=n 


THE 


Railway    Signal    Dictionary 


I'Z- 


'    - 


AN  ILLUSTRATED  VOCABULARY  OF  TERMS 
WHICH  DESIGNATE  AMERICAN  RAILWAY 
SIGNALS,  THEIR  PARTS,  ATTACHMENTS  AND 
DETAILS  OF  CONSTRUCTION,  WITH  DE- 
SCRIPTIONS OF  METHODS  OF  OPERATION 
AND  SOME  ILLUSTRATIONS  OF  BRITISH 
SIGNALS  AND  PRACTICE 


FIRST    EDITION 

COMPILED  1908  FOR 

THE    RAILWAY    SIGNAL   ASSOCIATION 

*  4 

By 

BRAMAN  B.  ADAMS  AND  RODNEY  HITT 
Associate  Editors  of  the  Railroad  Gazette 

UNDER   THE    SUPERVISION.  OF  THE    FOLLOWING    COMMITTEE  : 

C.  C.  ANTHONY,  Assistant  Signal  Engineer,  Pennsylvania  Railroad 

AZEL  AMES,  JR.,  Signal  Engineer,  Electric  Zone,  New  York  Central  &  Hudson  River  Railroad 

J.  C.  MOCK,  Electrical  Engineer,  Detroit  River  Tunnel  Company 


SECOND    EDITION 

RKVISED     1911    BY 

A.  D.  CLOUD,  Editor  of  The  Signal  Engineer,  and  H.  H.  SIMMONS,  Associate  Editor  of  the  Railway  Age  Gazette 

UNDER   THE   SUPERVISION    OF   THE    FOLLOWING    COMMITTEE1. 

J.  C.  MOCK,  Electrical  Engineer,  Detroit  River  Tunnel  Company 
C.  C.  ANTHONY,  Assistant  Signal  Engineer^  Pennsylvania  Railroad 
F.  P.  PATENALL,  Signal  Engineer,  Baltimore  iP'CVijo  Railroad'  :• 


1911 
RAILWAY   AGE  GAZETTE 

NEW  YORK:  83  Fulton  Street     CHICAGO:  Plymouth  Building 

THE   SIGNAL  ENGINEER 
CHICAGO  :  Plymouth  Building    NEW  YORK:  83  Fulton  Street 

THE    RAILWAY  GAZETTE 
LONDON:    Queen  Anne's  Chambers,  Westminster,  S.  W. 


RESOLUTION 


Adopted  by  the  Executive  Committee  of  the  Railway  Signal  Association,  January  8,  1907,  and 
approved  by  the  Association  at  its  annual  meeting  in  Milwaukee,  Wis.,  October  10,  1907: 

"WHEREAS,  The  Railroad  Gazette  has  proposed  to  publish  under  the  direction  of  the  Association,  an 
illustrated  dictionary  of  railroad  signals  and  signaling;  therefore  be  it 

"Resolved,  That  the  Railroad  Gazette  be,  and  hereby  is,  authorized  and  empowered  under  the 
supervision  of  a  committee  of  this  Association  to  publish  an  illustrated  dictionary  of  railroad  signals 
and  signaling." 

The  Executive  Committee  appointed  as  the  supervising  committee  the  members  of  the  Associa- 
tion's Committee  on  Definitions,  namely:  Charles  C.  Anthony,  Assistant  Signal  Engineer,  Pennsyl- 
vania Railroad;  Azel  Ames,  Jr.,  Signal  Engineer,  Electric  Zone,  New  York  Central  &  Hudson  River 
Railroad;  J.  C.  Mock,  Electrical  Engineer,  Detroit  River  Tunnel  Company. 

The  second  edition  was  prepared  under  the  supervision  of  the  Association's  Committee  on  Defi- 
nitions, for  1911,  namely:  J.  C.  Mock,  Electrical  Engineer,  Detroit  River  Tunnel  Company;  C.  C. 
Anthony,  Assistant  Signal  Engineer,  Pennsylvania  Railroad,  and  F.  P.  Patenall,  Signal  Engineer,  Bal- 
timore &  Ohio  Railroad. 


COPYRIGHT,  1912 
BY 

SlMAlONS-BoARDMAN    PUBLISHING    Co. 

NEW  YORK,  N.  Y. 


Ill 


THE    SIGNAL  DICTIONARY 


PREFACE  TO  THE  FIRST  EDITION 


Railway    signaling   is    a   comparatively   new   art,    and   a 

)idly  growing  one,  so  that  its  nomenclature  is  un- 
settled and  its  practices  varied;  and  numerous  changes 
of  a  somewhat  radical  nature  are  still  going  on.  The 
development  of  scientific  signaling,  as  distinguished 
from  the  earlier  and  empirical  methods  of  controlling 
the  movements  of  railway  trains,  has  proceeded  from 
a  curious  combination  of  motives ;  in  some  cases,  from 
the  enterprise  of  trained  men,  in  others  from  a  press- 
ing necessity  due  to  expansion  of  business,  and  in  still 
others  to  the  force  of  public  opinion,  both  the  public 
and  the  railway  officer  being  sometimes  actuated  by 
injudicious  haste.  That  w-e  are  not  yet  out  of  the  transition 
state  is  no  cause  for  surprise. 

In  making  a  signaling  dictionary  the  very  first  step 
calls  for  arbitrary  action.  Hand-motion  signaling,  with 
or  without  the  use  of  flags  and  lanterns,  is  excluded, 
because  those  features  have  no  need  of  the  services  of 
the  signal  engineer.  A  "slow-board"  is  a  fixed  signal, 
but  the  signal  engineer  scarcely  gives  it  a  thought.  On 
the  other  hand,  automatic  bells  at  highway  crossings 
logically  do  not  come  under  the  head  of  railway  signals, 
for  they  do  not  directly  affect  the  movement  of  trains; 
but  the  signal  engineer  does  take  cognizance  of  this  class, 
because  it  requires  skilled  attention  and  is  usually  put 
in  his  charge. 

In  fixed  signals,  which  constitute  the  subject  of  this 
work,  American  railway  officers  often  make  a  distinction 
which  is  wholly  arbitrary  and,  in  most  cases,  useless — 
that  between  interlocking  signals  and  block  signals. 
The  function  of  a  signal  being  clearly  stated,  the  Eng- 
lish nomenclature,  ignoring  this  distinction,  is  entirely 
adequate.  But  to  make  each  collection  of  drawings 
complete  in  itself,  we  recognize  this  distinction ;  and  the 
reader  will  find — under  the  two  different  heads — different 
illustrations  showing  semaphore  signals  exactly  alike. 

Other  uses  of  words  are  inexact,  yet  not  troublesome. 
The  noun  "signal"  usually  means  a  semaphore  signal  com- 
plete, yet  in  speaking  of  the  movements  of  a  signal,  espe- 
cially where  there  are  two  arms  on  a  single  post,  "signal" 
refers  to  the  movable  part  alone.  "Controlled  manual" 
means  signals  worked  by  hand  but  having  the  hand  levers 
fitted  with  electric  locks  by  which  the  man  working  the 
signals  is  subject  to  the  control,  under  certain  circum- 
stances, of  the  signalman  at  another  station,  and  also  to 
control  by  the  train  itself  through  track  circuits  connected 
with  the  lever  locks ;  but  there  are  now  at  least  three 
principal  divisions  of  this  subject,  so  that  the  simple  term 
'"controlled  manual"  has  little  meaning  until  it  is  explained. 
It  includes:  (i)  A  system  worked  without  track  circuits 
or  any  other  means  of  control  by  trains ;  (2)  one  worked 
with  a  short  track  circuit  at  each  block  station,  and  (3) 


with   a  track  circuit  throughout  the  length   of  the  block 
section. 

Practice  is  more  varied  than  nomenclature;  but  it  is 
not  so  inconsistent  as  it  seems,  for  with  suitable  limitations 
of  the  speeds  of  trains,  supplemented  by  careful  instruction 
of  enginemen,  the  extreme  requirements  of  the  uniformity 
enthusiasts  are  not  absolutely  essential.  For  example, 
thousands  of  miles  of  railway  equipped  with  home  block 
ngnals  have  very  few  distant  signals,  and  this  necessitates 
slackening  of  speed  in  snowstorms  and  fogs.  Many  block 
stations  on  single-track  lines  have  but  one  signal  for  each 
direction,  and  both  of  these  are  supported  on  a  single  post, 
opposite  the  station  office;  but  with  a  rule  requiring  trains 
to  approach  stations  with  speed  under  control,  this  ar- 
rangement is  workable.  On  many  roads  this  and  other 
deficiencies  of  the  block  system  are  overcome  by  con- 
tinuing in  force  the  time-table  regulations.  The  block 
system  is  a  valuable  means  of  safety  even  when  worked 
under  these  modifications. 

Semaphores  have  wholly  superseded  disks  for  signal- 
ing at  yards  and  terminals,  this  for  well-known  reasons ; 
but  disks  continue  in  favor  on  a  few  roads  for  automatic 
block  signaling,  and  their  use  is  not  inconsistent  with  the 
use  of  semaphores.  Likewise,  the  use  of  semaphores  to  be 
inclined  upward  to  indicate  "proceed,"  which  is  coming 
into  vogue  in  a  few  places,  is  not  inconsistent  with  the 
old  practice,  with  the  downward  inclination. 

In  those  drawings  which  show  the  color  indications 
used  in  signals  at  night,  "green  or  white,"  referring  to 
home  signals,  is  to  be  read  in  connection  with  "yellow  or 
green,"  referring  to  distant  signals.  Where  green  means 
clear,  yellow  is  the  color  for  caution  in  the  distant  signal 
(with  an  exception  as  shown).  The  long-standing  and  gen- 
eral practice  on  American  railways  at  night  is  white  for 
clear,  green  for  caution,  red  for  stop.  The  other  scheme, 
green  for  clear,  yellow  for  caution,  red  for  stop,  has  come 
into  favor  within  the  past  10  years  (in  England,  green 
for  clear  became  general  nearly  20  years  ago).  Signal  en- 
gineers are  practically  unanimous  in  their  view  that  the 
abolition  of  "white"  lights  for  giving  signal  indications  is 
desirable  everywhere. 

This  work,  like  the  Car  Builders'  and  the  Locomotive 
dictionaries,  is  necessarily  arranged  in  part  like  an  encyclo- 
pedia, for  on  many  subjects  the  drawings  may  be  called 
the  main  feature  and  the  text  secondary ;  and  in  signaling, 
far  more  than  in  these  other  arts,  extended  explanation 
is  necessary  in  connection  with  the  drawings.  The  reader 
will  at  once  recognize  the  propriety  of  the  arrangement. 

The  supervising  committee  and  the  editors  warmly  ap- 
preciate the  courtesies  of  the  railway  officers  and  manufac- 
turers who  have  furnished  drawings  and  information. 

B.  B.  A. 

NEW  YORK,  March,  1908.  R.  H. 


271650 


THE    SIGNAL    DICTIONARY 


IV 


PREFACE  TO  THE  SECOND  EDITION 


During  the  period  from  1908  to  1911,  inclusive,  the 
developments  in  railway  signaling  have  been  as  rapid, 
as  important,  and  as  extensive  as  in  any  other  previous 
period  of  twice  this  length.  The  aim  in  revising  this 
book  has  been  to  retain  descriptions  and  illustrations  of 
apparatus  which,  although  no  longer  made,  is  and  will 
remain  for  some  time,  in  rather  extensive  use,  as  well 
as  to  reflect  the  latest  work  of  the  manufacturers. 

Practically  all  of  the  standards  of  the  Railway  Signal 
Association  as  they  were  listed  in  the  report  of  the 
Committee  on  the  Manual  at  the  1911  convention,  with 
the  exception  of  some  designs  which  are  included  in 
the  specifications,  will  be  found  herein.  Some  of  the 
drawings  shown  were  submitted  for  the  approval  of  the 
association,  following  the  1911  meeting,  and  at  this 


writing  have  not  been  formally  approved.  Among 
these  are  the  standard  symbols  shown  on  pages  I  to 
13,  and  the  circuits  at  the  end  of  the  section  devoted 
to  electric  locking. 

The  arrangement  has  been  changed  to  mark  more 
distinctly  the  somewhat  arbitrary  division  of  the  sub- 
jects treated.  The  descriptive  matter  is  subordinate 
to  the  drawings,  which  form  the  main  feature  of  each 
section. 

The  supervising  committee  and  the  editors  warmly 
appreciate  the  courtesy  of  the  railway  officers  and 
manufacturers  who  have  furnished  drawings  and  in- 
formation for  their  assistance  in  the  work  of  revising 
the  dictionary.  A.  D.  C. 

CHICAGO,  November,  1911.  H.  H.  S. 


THE    SIGNAL    DICTIONARY 


A  BRIEF  RETROSPECT 


The  block  system  was  first  used  in  America  in  1863 
or  1864,  and  interlocking  about  1870.  Both  had  been 
well  developed  on  the  busy  railways  of  England,  so 
that  American  railway  officers  could  find  there  all  nec- 
essary examples;  but,  with  our  lighter  traffic,  progress 
was  rather  slow.  For  many  years  the  Pennsylvania, 
which  in  1872  leased  the  lines  east  of  Philadelphia,  on 
which  the  block  system  had  been  first  introduced,  was 
the  only  road  using  it.  A  few  roads  in  New  England 
began  using  wire-circuit  automatic  block  signals  about 
1871,  but  the  time-interval  rules  were  maintained  in 
full  force,  so  that  the  signals  were  of  little  use  in  in- 
creasing the  capacity  of  the  roads.  In  1879  the  track 
circuit  was  introduced,  making  automatic  block  signals 
effective  as  against  the  danger  of  false  clear  signals 
being  given  by  the  accidental  separation  of  a  train 
into  two  parts  (and  incidentally  affording  a  means  of 
detecting  broken  rails),  and  from  that  time  the  use 
of  the  automatic  system  has  progressed  as  fast  as  rail- 
ways have  found  themselves  able  to  make  the  heavy 
investment  necessary  to  install  it.  Automatic  block 
signals  are  now  in  use  on  about  20,000  miles  of  Ameri- 
can railways. 

Automatic  block  signals  must  work  without  the  care 
of  an  attendant,  and  most  of  them  at  places  remote 
from  a  source  of  power.  They  were  first  operated  by 
a  simple  electro-magnet  (the  enclosed  disk  signal), 
the  parts  being  made  very  light.  To  avoid  the  dis- 
advantage of  the  glass  enclosure  the  "clock-work"  was 
next  introduced,  this  apparatus  furnishing  power 
enough  to  move  a  disk  exposed  to  wind,  rain,  snow 
and  frost.  Disks,  however,  were  generally  regarded 
as  inferior  to  semaphores,  and  the  next  improvement 
was  the  electro-pneumatic  mechanism,  moving  full- 
sized  semaphores,  which  was  introduced  in  1885.  This 
system,  however,  with  its  air  pipe  the  whole  length  of 
every  line  which  is  signaled,  was  too  costly  for  roads 
with  any  but  the  heaviest  traffic,  and  it  was  not  until 
the  perfection  of  batteries  and  electric  motors  capable 
of  economically  operating  full-size  outdoor  semaphores 
(with  an  independent  source  of  power  at  each  signal) 
that  automatic  block  signals  became  universally  popu- 
lar. Since  1900  the  electric-motor  signal  has  made 
great  progress  and  is  now  used,  not  only  for  practically 
all  automatic  signaling,  but  also  at  the  majority  of 
power  interlocking  plants  and  at  a  good  many  mechani- 
cal plants,  the  introduction  of  the  electro-mechanical 
interlocking  machine  having  made  this  latter  applica- 
tion practicable.  Distant  signals  are  rapidly  coming 
to  be  motor-operated  instead  of  wire-connected,  espe- 
cially for  new  work. 

Until  within  the  past  10  years  single-track  lines — 
with  one  exception,  the  Cincinnati,  New  Orleans  & 
Texas  Pacific — made  little  use  of  automatic  signals,  for 
there  are  peculiar  difficulties  on  such  lines.  To  make 
the  signals  efficient  in  preventing  collisions  between 
trains  running  in  opposite  directions  the  controlling 
circuits  must  be  more  extended  and  complicated  than 
are  those  on  double  track,  for  each  of  two  trains  ap- 
proaching each  other  must  set  signals  at  "stop"  against 
the  opposing  train  so  far  in  advance  of  itself  as  to  insure 
that  both  trains  will  receive  stop  indications  in  time  to 
stop  before  meeting.  And,  in  addition,  when  a  train 
finds  a  signal  at  "stop"  it  must  not  proceed,  as  it  would 
on  double  track,  merely  looking  out  for  a  train  stand- 
ing or  moving  in  the  same  direction  as  itself,  but  must 
suffer  considerable  delay  by  sending  a  man  ahead  with 
a  red  flag  or  light,  because  there  is  the  possibility  that 
a  train  may  be  approaching  in  the  opposite  direction. 


In  spite  of  these  difficulties,  however,  automatic  sig- 
nals are  being  installed  in  large  numbers  on  single- 
track  lines. 

The  last  three  years  have  witnessed  considerable 
progress  in  this  respect  and  the  mileage  of  single- 
track  automatic  block  signals  has  much  more  than 
doubled  in  that  time.  Electric  railways  have  been 
the  cause  of  many  of  the  developments  in  the  appli- 
cation of  automatic  signals  to  single  track,  as  their 
conditions  have  required  such  a  thorough  study  of 
the  principles  involved  that  the  period  of  growth  and 
development  along  this  line  may  be  said  to  have  been 
fairly  well  completed. 

Automatic  signals  reach  their  highest  application  in 
such  installations  as  those  of  the  New  York  Subway 
and  the  Boston  and  Philadelphia  elevated  service, 
where  automatic  stops  are  provided  to  guard  against 
physical  or  mental  disablement,  or  carelessness,  on  the 
part  of  the  engineman  or  motorman.  The  service  per- 
formed by  the  sfgnals  in  such  intensive  situations  is 
decisively  shown  by  the  fact  that  during  the  last  year 
the  time-speed  signals  developed  in  the  New  York 
subway  have  effected  a  17  per  cent  increase  in  the 
passenger  carrying  capacity  of  the  subway  lines.  Be- 
cause of  the  difficulty  of  maintaining  the  auxiliary  ap- 
paratus generally  required  in  connection  with  an  auto- 
matic stop  on  lines  exposed  to  drifting  snow  and 
carrying  a  heavy  miscellaneous  traffic,  and  also  be- 
cause of  the  cost  of  maintenance  and  the  reduction 
in  the  traffic  capacity  of  the  railway  the  automatic 
stop  has  not  as  yet  been  used  except  in  special  con- 
ditions like  those  on  the  roads  named,  although  much 
experimenting  has  been  done  in  the  development  of 
these  auxiliaries. 

City  lines  of  dense  traffic,  worked  by  electric  power, 
have  also  adopted  costly  inventions,  marking  notable 
scientific  progress  in  signaling,  made  necessary  by  rea- 
son of  the  use  of  the  rails  of  the  track  as  conductors 
for  the  electric  current  which  propels  the  trains.  To 
work  track-circuit  signals  on  such  tracks  involves  the 
use  of  many  devices  not  employed  on  ordinary  rail- 
ways. 

Going  back  now  to  non-automatic  block  signals,  the 
first  extension  beyond  the  lines  of  the  Pennsylvania 
(except  about  15  miles  on  the  New  York  Central)  was 
on  single-track  lines  west  of  the  Alleghenies,  where  at 
first  the  "system"  was  little  more  than  a  rather  in- 
formal order  to  telegraph  operators  to  use  their  train- 
order  signals  as  block  signals.  A  train-order  signal  is 
ordinary  employed  to  stop,  for  the  delivery  of  written 
dispatcher's  orders,  trains  which  normally  would  pro- 
ceed, regardless  of  the  operator,  on  their  time-table 
rights;  and  the  change  was  simply  to  use  these  signals 
to  stop  every  train,  unless  the  last  preceding  train  had 
reached  the  next  station,  this  fact  being  reported  by 
telegraph  from  the  said  next  station.  But  this,  simple 
as  it  was,  and  though  frequently  suspended  as  regards 
freight  trains,  was  the  essence  of  the  main  feature  of 
the  block  system,  and  the  results  justified  the  practice. 
Block  signaling  is  not  complete  and  satisfactory  with- 
out interlocking  of  all  switches;  nor  without  distant 
signals;  nor  (if  not  automatic)  without  sufficiently  fre- 
quent stations  to  obviate  the  necessity  of  permissive 
signaling;  but  incomplete  signaling  has  proved  highly 
profitable.  The  least  complete  space  interval  system  is 
superior,  both  in  safety  and  economy,  to  any  scheme 
of  time  intervals,  with  its  dependence  on  complicated 
rules,  and  the  careful  use  of  flags,  torpedoes  and  fusees; 
on  a  high  degree  of  vigilance  in  conductors  and  flagmen 


THE    SIGNAL  DICTIONARY 


VI 


and  the  special  skill  of  dispatchers  and  station  op- 
erators. 

Since  1898  the  use  of  manual  block  signaling  has 
been  quite  rapidly  extended  throughout  the  country, 
and  it  now  covers  over  50,000  miles  of  road,  besides 
several  thousands  more  on  which  the  protection  is  less 
complete.  This  manual  signaling  is  on  lines  which 
carry  a  considerable  traffic,  but  which  yet  are  not 
profitable  enough  to  justify  the  initial  expenditure 
necessary  to  install  automatic  signals.  But  as  fast  as 
automatics  can  be  afforded  many  companies  are  sub- 
stituting them  for  the  other  system;  for,  once  installed, 
their  operation,  requiring  no  signalmen,  is  much  Ipss 
costly. 

The  alternating  current  has  been  applied  both  to 
steam  and  electric  railways  with  such  good  results 
from  the  standpoint  of  economic  installation  and  main- 
tenance that  its  future  is  very  promising  for  automatic 
signaling  in  general. 

From  the  beginning,  in  1870  or  1871,  interlocking 
made  slow  but  sure  progress.  In  the  large  passenger 
terminals  it  was  soon  seen  to  be  an  absolute  necessity, 
because  without  it  the  excessive  cost  of  the  wages  of 
signalmen  at  detached  switches,  the  danger  of  collisions 
due  to  imperfect  hand-signaling  and  to  fog,  and  the 
intolerable  delays  necessary  to  guard  against  these 
dangers,  often  put  a  serious  embargo  on  traffic.  The 
question  of  interlocking  thus  was  largely  one  of 
economy  rather  than  a  safety,  and  the  improvement 
was  introduced  mainly  at  terminal  yards  and  junctions 
and  crossings.  (At  crossings  it  economized  time,  fuel 
and  wear  by  making  unnecessary  the  stop  for  every 
train  formerly  required  at  all  grade  crossings.)  But 
as  speeds  of  trains  increased  interlocking  .was  found 
useful  at  all  stations  where  much  switching  was  done, 
for  it  obviates  the  slackening  of  the  speed  of  fast  trains, 
and  our  best  lines  now  have  interlocking  for  all  their 
busiest  stations. 

Power  operation  of  switches  (and  signals)  familiarly 
termed  "power  interlocking"  came  into  use  with  electro- 


pneumatic  block  signals.  Following  this,  machines 
working  wholly  by  electric  power  were  tried  as  soon 
as  electric  motors  were  sufficiently  developed,  and  the 
"low-pressure"  pneumatic,  with  no  electric  apparatus, 
came  soon  after.  The  "all-electric"  did  not  come  into 
general  use  until  about  1900;  but  it  has  now  supplanted 
the  "all-air."  At  small,  isolated  plants  it  is  economical 
because  of  the  simplicity  of  the  engine  (gasoline)  and 
generator  necessary  to  produce  the  electric  current. 

The  upper  quadrant  has  made  steady  progress,  and 
is  now  used  on  about  100,000  miles  of  railway.  Green 
for  clear  has  made  rapid  strides  in  replacing  the  white 
light,  and  its  application  covers  115,000  miles. 

The  work  of  both  the  signal  departments  and  manu- 
facturers in  late  years  has  been  along  the  line  of  im- 
proving what  already  exists  quite  as  much  as  in  ex- 
tending the  use  of  signaling  apparatus.  And  now  the 
interest  of  the  signal  department  in.  the  installation 
by  no  means  ceases  when  it  has  been  completed  and 
put  in  service,  for  the  question  of  economy  in  op- 
eration has  assumed  an  importance  almost  equivalent 
to  the  original  selection  of  the  material  to  be  used. 
It  has  become  a  matter  of  fact  that  some  of  the  old 
methods  of  handling  and  operating  signaling  apparatus 
are  not  as  economical  as  they  must  become  to  keep 
pace  with  the  efficiency  movement  in  all  lines  of  work. 

This  book  is  not  a  history;  and,  indeed,  much  of  the 
best  history  in  this  field  is  too  recent  to  be  satisfac- 
torily written;  but  the  foregoing  paragraphs  will  serve 
to  give  the  reader  who  is  not  familiar  with  the  subject 
some  idea  of  the  reasons  for  the  existence  of  the  ex- 
tensive and  varied  art  which  is  illustrated  in  the  fol- 
lowing pages.  Signaling  now  engages  the  attention 
of  the  best  engineering  talent  on  all  the  best  railways. 
The  signal  manufacturing  companies  of  the  country 
employ  millions  of  capital,  and  their  engineers  have 
met,  and  are  meeting,  innumerable  abstruse  and  in- 
tricate problems,  with  brilliant  success.  American 
signalmen  have  accomplished  both  progress  and  econ- 
omy, and  new  economies  are  still  being  effected. 


Vll 


THE    SIGNAL  DICTIONARY 


USE  OF  THE  BLOCK  SYSTEM   IN  THE  UNITED  STATES 

TABLE     PUBLISHED    BY    THE    INTERSTATE     COMMERCE     COMMISSION,    JANUARY    1,    191],     SHOWING    THE     AGi;i:K- 

GATE    LENGTH   OF   LINES    OR    PARTS    OF    LINES    OF    RAILROADS    IN    THE    UNITED    STATES    ON 

WHICH   THE    BLOCK    SYSTEM    IS    IN   USE    (MILES    OF    ROAD). 


The  use  of  alternating  current  in  connection  with  signal 
installations  is  reported  as  follows  : 

Auburn  &  Northern,  Cumberland  Valley,  Hudson  &  Man- 
hattan, and  Syracuse,  Lake  Shore  &  Northern.  All  automatic 
signals  are  controlled  by  a.  c.  track  circuits  and  operated  by 
a.  c.  signal  circuits. 

Long  Island :  77.7  miles  a.  c.  track  circuits ;  56.2  miles  of 
track  on  which  a.  c.  electric-motor  signals  are  used. 

New  York,  New  Haven  &  Hartford  :  71.4  miles  a.  c.  track 
circuits  with  automatic  signals ;  85.8  miles  a.  c.  track  circuits 
with  controlled  manual  signals  ;  8.1  miles  double  track  and  9.2 
miles  six-track  road  on  which  a.  c.  motor  signals  are  used. 

Northwestern  Pacific :  a.  c.  track  circuits  used  to  control 
all  automatic  signals ;  on  6  miles  of  track  a.  c.  electric-motor 
signals  are  used. 

Pennsylvania  :  33.5  miles  a.  c.  track  circuits  Philadelphia, 
Baltimore  &  Washington ;  5.2  miles  a.  c.  track  circuits  ;  West 
Jersey  &  Seashore,  76.3  miles  a.  c.  track  circuits. 


Automatic  train  stops  are  used  in  connection  with  block 
signals  on  the  Erie,  the  Hudson  &  Manhattan,  the  New  York 
City  Terminal  of  the  Pennsylvania,  and  the  suburban  lines  of 
the  Washington  Water  Power  Company.  On  the  Erie  the 
Harrington  automatic  stop  is  used  on  11.8  miles  of  one  track 
of  double  track  road.  On  the  Hudson  &  Manhattan  automatic 
stops  are  used  in  connection  with  all  signals.  In  the  Pennsyl- 
vania Terminal  in  New  York  automatic  stops  are  used  in  con- 
nection with  signals  throughout  the  tunnels,  covering  4.4  miles 
of  road,  or  13.7  miles  of  track.  The  Washington  Water  Power 
Company  uses  automatic  stops  In  connection  with  automatic 
signals  on  29  miles  of  track. 

The  Delaware,  Lackawanna  &  Western  and  the  Tide  Water 
Power  Company  operate  a  few  miles  of  road  by  means  of  the 
train  staff  without  electric  control.  So  far  as  known,  these 
are  the  only  two  installations  of  this  form  of  block  system. 
The  installation  on  the  Delaware,  Lackawanna  &  Western  is 
on  a  section  of  road  which  is  used  only  for  freight  trains. 


AGGREGATE  LENGTH  OF  LINES  AND   PARTS  OF  LINES  ON  WHICH  THE  BLOCK  SYSTEM  WAS  IN  USE 

ON  JANUARY  1,  1911 


Names  of  railroads. 

Permissive  signal- 
ing forbidden. 

Permissive  signaling  allowed. 

Rear-end    protec- 
tion only. 

Stop  at  station  rec- 
ognized  as   stop 
[for  signal   oppo- 
tsite  office. 

By  three-position 
signal. 

By     two-position 
signal   and   flag 
or  lantern. 

By  caution  card. 

Miles  of 
road. 

Miles  of 
track. 

Miles  of 
road. 

Miles  of 
track. 

Miles  of 
road. 

Miles  of 
track. 

Miles  of 
road. 

Miles  of 
track. 

Miles  of 
road. 

Miles  of 
track. 

Miles  of 
road. 

Miles  of 
track. 

1  4 

1  4 

Atchison,  Topeka  &  Santa  Fe: 

1841.9 
1559.9 

1,343.0 
561.1 

17.7 
•28.5 

7.7 
28.5 

* 

Coast  lines  

4.3 

4.3 

Gulf,  Colorado  &  Santa  Fe  

12.1 
418.3 

2.1 

464.9 

A  tlantic  Coast  Line  

56.5 
160.2 

105.6 
221.2 

373.1 

373.1 

474.8 

570.0 

Baltimore  &  Ohio  

886.5 
960.0 

1,626.7 
1,001.9 

Baltimore  &  Ohio  Southwestern  

960.0 

1,001.9 

960.0 

1,001.0 

4.7 

7.7 

.9 

4.8 

.9 
9.6 

193.8 

324.2 

Buffalo,  Rochester  <t  Pittsburgh  

2429.9 

558.7 

429.9 

558.7 

16.0 
59.7 

16.0 
67.1 

1  1  400  1 

1,526.0 

269.0 
>141.2 

269.0 
141.2 

Chicago  &  Alton  '.  

Chicago  &  Eastern  Illinois  

13.0 

13.0 

1218.4 

218.4 

Chicago  &  North  Western  

">2  524  6 

2,639.9 

2,524.6 
9.5 
8,690.6 
1,330.» 

2,639.9 
22.2 
9,327.5 
1,354.6 

Chicago  &  Western  Indiana  

9.5 

22.2 

18,637.3 

9,274.2 

6,303.3 

6,303.3 

1.5 

1.5 

11,329.4 

1,353.1 

525.0 

525.0 

187.3 
2.0 

187.3 
2.0 

13  619  7 

4  058.5 

Chicago,  Milwaukee  &  Puget  Sound  . 

»  1,362.  7 
19.0 

1,362.7 
9.0 

1  1  362.  7 

1,362.7 

Chicago,  Rock  Island  &  Pacific  

1988.7 
»»  656.0 

988.7 
720.1 

997.7 

997.7 

Chicago,  St.  Paul,  Minneapolis  &  Omaha...  . 

Cincinnati,  Hamilton  &  Dayton  

33.9 

47.8 

33.9 
99.0 

47.8 
99.0 

Cincinnati,  Indianapolis  &  Western..  . 

»99.0 

99.0 

Colorado  Midland  

2.0 

2.0 

Cornwall  &  Lebanon  .-...  . 

•22.0 

35.7 

Cumberland  &  Pennsylvania  

»7.3 
17.6 

13.3 
17.6 

Cumberland  Valley  

2.0 

5.8 

2.0 

5.8 

Delaware,  Lackawanna  &  Western  

Duluth  &  Iron  Range  

16.2 

17.6 

56.0 

56.0 

Elgin,  Joliet  &  Eastern  

11.3 

11.3 

Erie  

»  1,075.  8 

1,508.1 

1,075.8 
248.8 
22.4 
26.1 

1,508.1 
25T.2 
32.2 
26.1 

Chicago  &  Erie  

»248.8 
«22.4 
26.1 
«34.7 
108.5 

257.2 
32.2 
26.1 
53.4 
108.5 

Columbus  &  Erie  

New  Jersey  &  New  York  

Evansville  <fe  Terre  Haute  

108.5 
n  239.  8 

108.5 
239.8 

18.7 

18.7 

n  239.8 

239.8 

Hocking  Valley  

144.0 

144.0 

Illinois  Central  

14.0 
24.0 

19.0 
24.0 

Illinois  Traction  

Iowa  Central  

«11.0 

11.0 

1.3 
2.5 

1.3 

2.5 

Kansas  City,  Clinton  &  Springfield  

Kentucky  &  Indiana  Bridge  &  R.  R.  Co  

11.1 

17.9 

Kentwood  &  Eastern  

3.3 
3.4 
714.3 

3.3 

5.8 
77C.7 

Lackawanna  &  Wyoming  Valley  

Long  Island  

22.7 

45.4 

495.9 
3.7 

599.5 
3.7 

Marquette  &  Southeastern  

Minneapolis,  St.  Paul  &  Sault  Ste.  Marie 

54.9 
5.7 
12.7 

54.9 
5.7 
14.3 

J2,*396  3 

2,400.7 

Missouri  Pacific  

12.9 

19.9 

St.  Louis,  Iron  Mountain  &  Southern  

Missouri,  Kansas  &  Texas  

8.6 

8.6 

Mobile  &  Ohio    

»47.8 

47.8 

47.8 

47.8 

47.8 

47.8 

Nashville,  Chattanooga  &  St.  Louis  

1  104.  6 

116.4 

Newburgh  &  South  Shore  

6.2 

11.4 

6.2 

11.4 

6.2 

11.4 

New  York  Central  Lines: 
Boston  &  Albany  

1.9 

3.7 

Chicago,  Indiana  &  Southern... 

203.7 

263.6 

Cleveland,  Cincinnati,  Chicago  &  St.  Louis  
Lake  Erie  &  Western  

905.2 
18.6 

1,267.5 
18.6 

19.3 

19.3 

22.6 

22.6 

838.1 

1,188.6 

2853.3 

862.3 

Lake  Shore  &  Michigan  Southern  

11,056.1 
190.5 
•87.7 

1,128.0 
90.5 
87.7 

996.0 
90.5 
87.7 

996.0 
90.5 

87.7 

1,056.1 
90.5 
87.7 
920.3 

1,128.0 
90.5 

87.7 
939.7 

Dunkirk,  Allegheny  Valley  &  Pittsburg.  . 

Lake  Erie,  Alliance  &  Wheeling  

Michigan  Central  

920.3 
2,345.1 
82.2 
22.7 
6.3 
12.9 
1.3 
250.5 

939.7 
3,379.1 
84.7 
25.6 
6.3 
12.9 
1.3 
250.5 

New  York  Central  &  Hudson  River  

129.6 
4.3 

231.3 
4.3 

Peoria  &  Eastern  

84.0 

84.0 

Pittsburg  &  Lake  Erie  

New  York,  New  Haven  &  Hartford  . 

M29.5 

862.6 

87.5 
910.7 

87.5 
910.7 

177.5 

225.4 

Norfolk  &  Western  _  

U,056.5 

1,135.1 

1222.0 

229.1 

Northern  Pacific  

992.2 

1,277.7 

992.2 

1,277.7 

Northwestern  Pacific  

1  Permissive  signaling  is  practiced  only  in.  the  case  of  a  freight  train  following  a  freight  train,  or  in  similar  movements  where  neither  train  carries  passengers. 
1  By  dispatcher.  '  By  ruler 


THE    SIGNAL    DICTIONARY 


Vlll 


AGGREGATE  LENGTHS  OF  LINES  AND  PARTS  OF  LINES  ON  WHICH  THE  BLOCK  SYSTEM  WAS  IN  USE 

ON  JANUARY  1,  1911  — Continued 


Names  of  railroads. 

Automatic  block  signals. 

Nonautomatic  block  signals. 

Total  auto- 
matic and 
nonautomatic. 

Total  passenger 
lines  operated. 

Percentage  block-signaled 
(miles  of  track). 

33 

Double  track. 

EH 

Four  track. 

Total. 

Single  track. 

Double  track. 

EH 

M 
Si 

Total. 

•d 
"3 
S 

•ij 

"o 
S, 
1 

•d 
| 

J2 
1 

Miles  of  track. 

Miles  of 
road. 

Miles  of 
track. 

"3  . 
|| 

ll 

j-H    +J 

24.0 

24.0 
11.0 
1.3 
2.5 

24.0 
11.0 
1.3 
2.5 

24.0 
11.0 
2.1 
2.5 

24.0 
11.0 

2.1 
2.5 

415.0 
503.0 
162.9 
150.7 
11.1 
30.0 
22.6 
67.2 

415.0 
503.0 
162.9 
156.7 
17.9 
30.0 
43.4 
07.2 

5.7 
2.2 
1.3 
1.6 

100.0 
11.0 
13.3 

11.0 

.8 

.8 

.f 

1.3 

2.5 

4.S 

5.S 

5 

11.1 
3.3 

3.4 

17.9 
3.3 

5.8 

11.1 
3.3 

3.4 

17.9 
3.3 

5.8 

3.3 

1.0 

2.4 

.7 

.7 

.7 

Lehigh  Valley  
Long  Island  
Louisville  &  Nashville  

14.1 
4.0 
40.9 
415.1 

439.3 
96.8 
22.3 
57.7 

34.6 
3.3 

13.0 
8.8 

501.0 
112.9 
63.2 
472.8 

1,048.6 
242.7 
85.5 
530.5 

652.0 
'"392."  3 

62.3 
22.7 
103.6 

714.3 
22.7 
495.9 

776.7 
45.4 
599.5 

1,215.3 
135.6 
559.1 
472.8 
3.7 
2,451.2 
14.5 
99.5 
135.1 
52.5 
.5 
104.6 
6.2 
38.0 

208.5 
208.7 

924.5 
871.9 
1,574.9 

90.5 
87.7 
1,192.2 
2,856.2 
86.5 
171.5 
707.5 
147.6 
1,652.2 
1,231.7 
264.4 
2,624.4 
143.9 
11.4 
58.0 
427.7 
1,093.4 
373.1 

1,113.3 
173.5 
361.9 
6.0 
54.2 
626.8 
122.6 
6.2 
38.1 
7.1 
35.9 

305.0 
92.1 

334.8 
15.5 
87.7 

757^4 
84.7 
157.6 
61.6 
7.0 
.4 

3.9 

I  8^5  ^ 
'  28&1 
685.0 
530.8 
3.7 
2,455.6 
14.5 
131.6 
145.  3 
57.2 

116!  4 
11.4 
76.0 

614.3 
273.6 

1,286.8 
880.9 
2,  737.  7 

90.5 
87.7 
1;483.5 
4,599.1 
89.0 
417.2 
1,431.6 
259.2 
1,991.1 
1,653.9 
275.9 
4,  703.  2 
161.3 
11.4 
60.2 
609.3 
1,891.0 
682.7 

1,826.3 
306.2 
422.8 
12.0 
54.2 
1,173.9 
209.5 
8.0 
38.1 
11.9 
35.9 

305.0 
92.5 

404.1 
31.0 
166.4 
.3 
795.2 
84.7 
157.6 
61.6 
14.0 
.4 

7.8 
1.1 

1,171.5 
391.9 
4,372.0 
907.  (i 
50.8 
3,423.4 
3,072.0 
3,708.4 
3,  178.  5 
825.0 
66.7 
1,  230.  1 
Fn 
38.0 

351.6 
309.4 

1,832.9 
832.5 
1,452.7 

90.5 
87.7 
1,192.2 
2,873.7 
337.9 
183.9 
1,926.4 
492.8 
1,671.6 
5,303.4 
330.6 
3,261.0 
177.8 
148.4 
536.7 
439.7 
1,315.0 
639.4 

1,415.3 
318.2 
797.0 
15.4 
1,534.2 
875.3 
163.6 
25.5 
38.1 
21.7 
53.3 

305.0 
290.  C 

335.4 
15.5 
87.7 
251.6 
4,  726.  6 
117.0 
265.6 
61.6 
10.0 
622.7 

15.7 
904.4 

1,741.3 

549.5 
4,543.0 
967.2 
50.8 
3,  427.  8 
3,072.0 
3,767.0 
3,318.8 
825.0 
66.7 
1,241.9 
ight  line. 
76.0 

602.0 
374.3 

2,214.7 
841.5 
2,  596.  6 

90.5 
87.7 
1,483.5 
4,674.5 
340.4 
420.4 
2,967.1 
626.2 
2,025.5 
5,  752.  6 
342.0 
5,  479.  5 
195.8 
148.4 
547.3 
635.9 
2,  125.  6 
945.5 

2,  140.  7 
455.6 
868.1 
26.6 
1,541.4 
1,452.3 
251.6 
27.3 
38.1 
26.6 
53  3 

305.0 
295.4 

404.  6 
31.0 
166.4 
251.6 
4,764.4 
117.0 
265.6 
61.6 
19.8 
622.7 

27.7 
904.4 
2,782.9 
6,  898.  b 
9.2 

1,275.0 
140.3 
282.1 
441.8 
6,671.4 
20.1 
22.8 
432.0 
44.5 
25.5 
15.7 
220.0 
451.0 
126.3 
14.8 
4,088.2 
1,140.9 
1,468.1 
4.8 
435.6 
2,  056.  1 
63.9 
64.4 
20.4 
29.0 
921.6 

100.0 
52.4 
15.1 
54.8 
7.3 
71.6 
.2 
2.5 
4.4 
6.9 
.7 
9.3 

100.0 

85.4 
73.1 

59.9 
100.0 
100.0 

100.0 
100.0 
100.0 
98.4 
26.1 
99.2 
47.7 
41.4 
97.1 
28.7 
80.7 
85.8 
82.4 
7.7 
11.0 
95.7 
89.0 
72.2 

85.3 
67.2 
48.9 
48.8 
3.5 
80.8 
.83.3 
29.3 
100.0 
44.7 
67.4 

100.0 
31.7 

99.8 
14.7 
100.0 

16.7 
72.3 
60.5 
100.0 
77.7 

28.5 
.1 
7.6 
30.3 
100.0 

21.9 
73.9 
33.8 
24.9 
39.3 
96.5 
100.0 
4.6 
27.6 
55.7 
39.5 
.1 
41.7 
19.8 
17.6 
48.7 
37.0 
41.0 
12.5 
.5 
93.8 
12.8 
100.0 
100.0 
100.0 
1.2 

3.7 

3.7 

2,451.2 
8.6 
18.6 
12.7 

47.8 

3.7 
2,  455.  C 
8.6 
25.6 
14.3 
47.8 

Minneapolis,  St.  Paul  &  Sault  Ste.  Marie.. 

2,446.8 

4.4 

Missouri,  Kansas  &  Texas  

5.9 

5.9 
80.9 
122.4 
4.7 

5.9 
106.  0 
131.0 
9.4 

8.0 
ll.fi 
11.1 
47.8 

'i'.o 

1.6 

Missouri  Pacific  
St.  Louis,  Iron  Mountain  &  Southern.. 
Mobile  &  Ohio 

55.2 
113.8 

25.7 
8.6 
4.7 

.5 

.5 

.5 

92.8 

11.8 

104.6 
6.2 

116.4 
11.4 

1.0 

5.2 

38.6 

132.9 
5.0 

38  0 

76  0 

New  York  Central  lines: 
Boston  &  Albany  

50.1 

23.6 

206.6 
5.0 

510.6 
10.0 

"143.8 

1.9 
59.9 

1.9 

203.7 

924.5 

871.9 
1,056.1 

90.5 
87.7 
920.3 
2,474.7 
86.5 
22.7 
435.8 

3.7 
263.6 

1,286.8 
880.9 
1,128.0 

90.5 
87.7 
939.  6 
3,610.4 
89.0 
25.6 
868.9 

Cleveland,  Cincinnati,  Chicago  &  St. 

562.7 

361.8 

862.9 

9.0 

Lake  Shore  &  Michigan  Southern  
Dunkirk,    Allegheny    Valley    & 
Pittsburg 

6.9 

173.2 

98.4 

240.3 

518.8 

1,609.7 

996.0 
90.5 

48.3 

11.8 

Lake  Erie,  Alliance  &  Wheeling 

87.7 

Michigan  Central  '  
New  York  Central  &  Hudson  River.  .  . 
Peoria  &  Eastern 

""z.'o 

271.9 
262.4 

"6.3 

iio.'s 

27i.9 
381.5 

543.9 
988.7 

901.0 
1,632.0 
84.0 

19.3 
688.5 
2.5 

"is.  4 

13S.S 

Pittsburg  &  Lake  Eric 

101.8 

47.0 

148.8 

391.6 

19.8 

2.9 

New  York,  New  Haven  &  Hartford*...... 
New  York,  Ontario  &  Western  

17.5 
36.0 

245.0 
111.6 

9.2 

271.7 
147.6 

562.7 
259.2 

154.3 

205.7 

75.8 

Norfolk  &  Western  
Northern  Pacific  
Northwestern  Pacific  

68.0 
101.5 
2.5 

272.8 
136.7 
11.4 

340.8 
238.2 
13.9 

613.6 
374.9 
25.4 

1,245.3 
708.0 
250.5 

66.1 
285.5 

1,311.4 
993.5 
250.5 
2,361.5 
143.9 
11.4 
58.0 
427.7 
749.1 
333.9 

1,102.1 
80.1 
361.9 
6.0 
39.0 
240.5 
35.7 
1.6 
38.1 

1,377.5 
1,279.0 
250.5 
3,  769.  0 
161.3 
11.4 
60.2 
609.3 
1,084.5 
561.0 

1,797.1 
113.1 
422.8 
12.0 
39.0 
337.4 
35.7 
1.6 
38.1 

58.0 

4.9 

200.0 

262.9 

934.2 

1,  428.  2 
126.5 

708.3 
17.4 

25.8 

199.2 

Cleveland,  Akron  &  Columbus  . 

11.4 

Grand  Rapids  &  Indiana 

55.8 

2.2 

Northern  Central  

287.1 

120.1 

20.5 

"is."  3 

20.6 

Pennsylvania  Company  
Philadelphia,  Baltimore  &  Washington 
Pittsburg,  Cincinnati,  Chicago  &  St. 
Louis  

273.7 
18.2 

23.3 

47.3 
21.0 

3.4 

344.3 
39.2 

11.2 
93.4 

806.5 
121.7 

29.2 
193.1 

418.9 
154.5 

507.2 
47.1 
300.9 

325.0 
147.0 

515.4 
33.0 
61.0 

5.2 
17.1 

58.9 

7.8 

West  Jersey  &  Seashore  
Vandalia  

87.1 

6.3 

Peoria  &  Pekin  Union  

6.0 

Pere  Marquette  •  

15.2 

15.2 

15.2 

39.0 

Philadelphia  &  Reading  

6.2 

324.0 
86.9 

42.1 

14.0 

386.3 
86.9 

836.5 
173.8 

143.6 
35.7 

96.9 

Atlantic  City  

Northeast  Pennsylvania  
Perkiomen  

2.8 

1.8 

4.6 

6.4 

1.6 
38.1 

*  Philadelphia,  Newton  &  New  York  . 

3.8 

1.8 

1  5 

7.1 

11.  S 

Reading  &  Columbia  

35.9 

( 

35.9 

305.0 

35.9 
305.0 

Qulncy,  Omaha  &  Kansas  City  and  Iowa 
&  St.  Louis  

305.0 

Queen  &  Crescent  Route: 
Alabama  Great  Southern  

91.7 

.4 

92.1 

92.5 

Cincinnati,    New    Orleans    &    Texas 
Pacific  
New  Orleans  &  Northeastern  
Richmond,  Fredericksburg  &  Potomac  

2C4.9 

09.2 
15.5 

334.1 
15.5 

403.4 
31.0 

.7 

'"o.'o 

""78.'7 

.7 

""87.'7 

j 

157!  3 
84.7 
157.6 
61.6 
1.1 

.7 

"i&6.'4 
.      .3 
157.3 
84.7 
157.6 
61.6 
2.2 

St.  Joseph  <t  Grand  Island  

St.  Louis  &  San  Francisco 

562.3 

37.8 

600.1 

637.9 

157.3 
84.7 

Beaumont,  Sour  Lake  &  Western  .     .  . 

New  Orleans,  Texas  &  Mexico  

157.6 

Orange  &  Northwestern  

61  6 

St.  Louis  Merchants  Bridge  Terminal  

5.9 

5.9 

11.8 

1.1 

St.  Louis  Southwestern  

.4 

.4 

.4 

San  Francisco,  Oakland  &  San  Jose  Con- 
solidated   

3.9 

3.9 

7.8 

San  Pedro,  Los  Angeles  &  Salt  Lake  

1.1 

1.1 

1.1 

1.1 

Seaboard  Air  Line  

213  5 

213.5 

213.5 
2,082.9 

213.5 
1,838.6 
4.6 

279.1 
103.6 
95.3 
109.8 
2,  453.  1 
10.9 
12.7 
10.0 
6.5 

213.5 
2.088.9 
9.2 

279.1 
103.6 
95.3 
109.8 
2,621.0 
21.7 
22.8 
20.0 
13.0 
14.2 
6.2 
.3 
188.0 
24.4 
2.6 
1,990.5 
433.0 
602.9 
.6 
2.2 
1,929.1 
8.2 
64.4 
20.4 

2,782.9 
6,  619.6 
4.6 

1,270.5 
140.3 
241.9 
438.4 
6,  447.  7 
10.1 
12.7 
422.0 
33.0 
12.7 
11.3 
220.0 
451.0 
126.3 
7.4 
3,467.3 
1,140.9 
1,442.4 
4.8 
435.1 
1,954.9 
59.8 
32.2 
2.1 

Southern  

3.0 

3  0 

6  0 

1  588  3 

247  3 

1,835.6 

Southern  Illinois  &  Missouri  Bridge 

4.6 

4.6 

9.2 

Southern  Pacific,  Atlantic  System: 
Galveston,  Harrisburg  &  San  Antonio.. 

279.1 

279.1 

279.1 

Louisiana  Western  

103.6 

103  6 

103  6 

Morgan's  Louisiana  &  Texas  

95.3 

95.3 

MI 

Texas  &  New  Orleans...   . 

109.8 

109.8 

109.8 

Southern  Pacific:  Pacific  System  .  .  . 
Staten  Island  Rapid  Transit.  .  . 

2,189.2 

164.9 
10.9 

1.0 

2,  355.  1 
10  9 

2,523.0 
21  7 

98.0 

98.0 

98.0 

Staten  Island.  

2  5 

10.2 

12.7 
10.0 

22.8 
20.0 

Spokane,  Portland  <t  Seattle  

10.0 

Syracuse,  Lake  Shore  4  Northern  

C.  5 

6.5 
6.0 

13.0 
12.0 

Terminal  R.  R.  Association  of  St.  Louis 

C.  0 

1.1 

1.1 
6.2 

Q 

2.2 
6.5 

7.1 
6.2 

188.1 
24.4 

Tidewater  Power  Co  

6  2 

Toledo,  Peoria  &  Western  

Toledo,  St.  Louis  &  Western  

188  0 

188.0 

188.0 

Ulster  &  Delaware  

24.4 

24.4 

24.4 

Union  Pacific  
Oregon  R  .  R  .  &  Navigation  Co  ! 
Oregon  Short  Line  

871.0 
433.0 
551.5 

.6 
551.0 

25.7 

1.7 

.6 
1,423.7 
433.0 
577.2 

1.2 

1,979.1 
433.0 
602.9 

1.4 
11.4 

1.4 
11.4 

1.4 
11.4 

2.0 
1,435.1 
433.0 
577.2 
.6 
2.2 
1,827.9 
4.1 
32.2 
2.1 

Virginia  A  Kentucky  

6 

.6 
2.2 

1,820.7 

.6 
2.2 
1,914.7 

Virginian  

2  2 

Wabash  Pittsburg  Terminal'.  .... 

7.2 
4.1 

7.2 
4.1 

14.4 
8.2 

1,726.7 

94.  C 

Washington  Southern  

32  2 

32.2 

64.4 

Washington  Terminal2  

1.1 

1.0 

2.1 
29  0 

20.4 
29  0 

Washington  Water  Power  Co  

29.0 

29.  C 
11.2 

29.0 
11.2 

29.0 
921.  fj 

Western  Pacific  

11.2 

11.2 

11.2 

Total  

8,312.2 

8,225.4 

331.2 

34Z7 

17,711.5 

29,202.444,897.1 

7,913.  1 

257.  9 

489.5 

53,557.6 

63,505.5 

71,269.1 

92,707.9 

172,389.9 

195,922.4 

1  (Michigan  Central.)    243.1  miles  double  track  automatic  block  in  Canada  not  shown  in  these  tables. 

2  (Illinois  Central;  New  York,  New  Haven  &  Hartford;  Pennsylvania;  Washington  Terminal.)    Include  road  with  more  than  4  tracks. 


IX 


THE    SIGNAL    DICTIONARY 


KINDS  OF  AUTOMATIC  SIGNALS  IN  USE 


Names  of  railroads. 

Exposed  disk. 

Inclosed  disk. 

Semaphores. 

Normal 
clear 
(miles 
of 
track). 

Norma 
danger 
(miles 
of 
track). 

Total  automatic  signals. 

Electropneu- 
matic. 

Electric  motor. 

Electro-  gas. 

Miles  of 
road. 

Miles  of 

track. 

Num- 
ber of 
block 
sec- 
tions. 

Miles  of 
road. 

Miles  of 
track. 

Miles  of 
road. 

Miles  of 
track. 

Miles  of 
road. 

Miles  of 
track. 

Miles  of 
road. 

Miles  of 

track. 

Miles  of 
road. 

Miles  of 
track. 

Atchison,  Topeka  &  Santa  Fe: 
Eastern  lines,  i  

13.3 

26.6 

66.0 
35.8 
14.5 

126.3 
38.2 
15.5 

152.9 
38.2 
20.9 
10.8 
28.3 
6  5 

79.3 
35.8 
19.9 
10.8 
15.2 
6.5 
218.1 
10.8 
14.0 
697.1 
13.8 
7.9 
212.4 
183.0 
561.0 
107.1 
739.4 
17.8 
42.4 
125.9 
109.6 
1.3 
932.9 
32.6 
6.2 
34.3 
6.7 
410.0 
584.7 
5.0 
227.1 
42.3 
10.5 
2.7 
130.8 
312.2 
6.6 
.8 
.7 
501.0 
112.9 
63.2 
472.8 
5.9 
80.9 
122.4 
4.7 
.5 
38.0 

205.9 
5.0 
518.8 
261.3 
379.4 
148.8 
271.7 
147.6 
340.8 
238.  2 
13.9 
257.9 
344.  3 
39.2 
11.2 
93.4 
15.2 
401.6 
86.9 
4.6 
7.1 

92.1 
334.1 
15.5 

600.1 
5.9 
.4 

3.9 
1.1 
3.0 

4.6 

279.1 
103.6 
95.3 
109.8 
2,355.1 
10.9 
6.5 
6.0 
24.4 
.0 
1,423.7 
433.0 
577.2 
7.2 
4.1 
2.1 
29.0 
11.2 

152.9 
38.2 
20.9 
10.8 

6.5 
430.1 
20.8 
28.0 
1,273.7 
27.6 
7.9 
477.2 
366.0 
705.9 
210.6 
1,504.6 
35.6 
97.2 
190.8 
213.3 
1.3 
1,212.5 
32.6 
12.4 
48.6 
13.4 
696.3 
1.116.3 
8.0 
484.0 
84.6 
21.0 
4.3 
253.1 
620.9 
6.6 
.8 
.7 
1,048.6 
242.7 
85.5 
530.5 
5.9 
106.0 
131.0 
9.4 
.5 
76.0 

495.4 
10.0 
1,609.7 
522.5 
980.6 
391.6 
562.7 
259.2 
613.6 
374.9 
25.4 
906.0 
806.5 
121.7 
29.2 
193.1 
15.2 
859.4 
173.8 
6.4 
11.9 

92.5 
403.4 
31.0 

637.9 
11.8 
.4 

7.8 
1.1 
6.0 
9.2 

279.1 
103.6 
95.3 
109.8 
2,  523.  0 
21.7 
13.  I) 
12.0 
24.4 
1.2 
1,979.1 
433.0 
002.9 
14.4 
8.2 
20.4 
29.0 
11.2 

92 
36 
19 
8 
35 
3 
602 
32 
35 
1,615 
59 
7 
734 
262 
368 
165 
1,162 
59 
38 
182 
203 
1 
1,252 
50 
6 
78 
13 
1,013 
1,558 
5 
579 
88 
22 
3 
219 
535 
8 
1 
1 
1,068 
386 
132 
542 
8 
90 
122 
3 
1 
118 

634 
19 

1.611 
359 
1,282 
207 
591 
150 
594 
401 
42 
1,556 
1,082 
150 
70 
249 
11 
993 
03 
8 
10 

62 
326 
16 

553 
30 
1 

76 
1 

9 

18 

204 
73 
72 
77 
2,177 
50 
26 
16 
20 
2 
1,585 
308 
463 
25 
11 
13 
23 
S 

Western  lines  

Coast  lines  

5.4 

5.4 

Gulf,  Colorado  &  Santa  Fe  

8.3 

8.3 

2.5 

15.2 
6.5 
107.1 
9.8 
14.0 
687.4 
13.8 

2.5 

28.3 
6.5 
211.6 
18.8 
28.0 
1,254.3 
27.6 

Atlantic  Coast  Line.  ....              

Auburn  &  Northern  

Baltimore  &  Ohio  

9.9 

1.0 

9.9 
2.0 

7.5 

22.'  4 

93.6 

186.2 

430.1 

Baltimore  &  Ohio  Chicago  Terminal  

20.8 

Baltimore  &  Ohio  Southwestern  

28.0 
19.4 

Boston  &  Maine  

.8 

1.6 

8.9 

17.8 

1,254.3 
27  6 

Boston,  Revere  Beach  &  Lynn  

Butte,  Anaconda  &  Pacific  

7.9 

7.9 

7  9 

Central  of  New  Jersey  

29.7 

116.0 

163.3 
183.0 
561.0 

323.2 
366.0 
705.9 

19.4 

38.0 

439.2 
366.0 
183.0 
210.6 
1,504.6 

38.0 

Chesapeake  &  Ohio  

Chicago  &  Alton  

522.9 

Chicago  &  Eastern  Illinois  l  

8.7 
736.5 

13.8 
1,498.8 

-^ 

-5.'8 

98.4 

196.8 

Chicago  &  North  Western  ,  

Chicago  &  Western  Indiana  

17.8 

35.6 

35  6 

Chicago,  Burlington  &  Quincy  

23.0 

46.0 

2,0 

8.0 

17.4 
125.9 

43.2 
190.8 

97  2 

Chicago  Great  Western  

190.8 
197.4 
1.3 

Chicago,  Milwaukee  &  St.  Paul  
Chicago,  Peoria  &  St.  Louis  Ry.  of  111  

2.4 

2.4 

103.7 
1.3 

207.4 
1.3 

3.5 

3.5 

15.9 

Chicago,  Rock  Island  &  Pacific  

6.0 

12.0 

926.9 

1.200.5 

1,209.5 
32  6 

3.0 

Chicago,  Rock  Island  &  Gulf  

33.6 

32.6 

Chicago,  St.  Paul,  Minneapolis  &  Omaha  

6.2 

12.4 

12.4 
48.  « 
13  4 

Cincinnati,  Hamilton  &  Dayton  

34.3 

48.6 

Cumberland  Vallev  '  •.  

6.7 

13  4 

Delaware  &  Hudson  
Delaware,  Lackawanna  &  Western  
Elgin,  Joilet  &  Eastern  

.      38.4 
•     26.6 

76.8 

51.  a 

"'558.'!' 
5.0 

'i.'oes.T 

8.0 

371.6 

619.5 

I,'il6.'3 
8.0 
5.2 
84.6 

690.3 

Erie..  

227.1 

484.0 

478.8 

Erie  &  Jersey  

42.3 

84.6 

New  Jersey  &  New  York  

10.5 

21.0 

21.0 

Grand  Trunk  

2.7 

4.3 

4  3 

Great  Northern  

130.8 

253.1 

251.1 
254.6 
6.6 

8 

2.0 

366.3 

Illinois  Central  

29  5 

104  2 

118.8 
6.6 
.8 

186.9 
6.6 
.8 

163.9 

329.8 

Yazoo  A  Mississippi  Valley  „ 

Kanawha  &  Michigan  

Lehigh  &  New  England  

.7 

.7 

7 

Lehigh  Valley  „  
Long  Island  

251.2 

534.6 

233.8 
112.9 

482.0 
242  7 

16.0 

32.0 

""238."7 
85  5 

1,048.6 
4.0 

Louisville  &  Nashville  

63.2 

85.5 

Maine  Central  

472.8 

530.5 

530  5 

Missouri,  Kansas  &  Texas  

.5 

.5 

5.4 

5.4 

5.9 

Missouri  Pacific  

80.9 
122.4 

106.0 
131.0 

106.0 
131.0 

St.  Louis,  Iron  Mountain  &  Southern  

Mobile  &  Ohio  

4  7 

9  4 

9  4 

Monongahela  

.5 

.5 

.5 

New  York  &  Long  Branch  

38.0 

182,5 
5.0 
336.4 
193.8 
416.0 
148  8 

76.0 

447.7 
10.0 

928.9 
387.6 
944.7 
391  6 

76.0 

New  York  Central  Lines: 
Boston  &.  Albany  *  

16.2 

33.3 

7.2 

14.4 

154.9 
10  0 

850.5 

Chicago,  Indiana  &  Southern  

Lake  Shore  &  Michigan  Southern  

5.3 

5.3 

177.1 

""a.i 

675.5 

"ie.2 

934.2 
522.5 
695.4 
391  G 

675.5 
"285."2" 

Michigan  Central  »  

New  York  Central  &  Hudson  River  4  

67.5 
9.9 

134.9 
19.7 

Pittsburg  &  Lake  Erie  

New  York,  New  Haven  &  Hartford  
New  York,  Ontario  &  Western  
Norfolk  &  Western  

177.1 
65.  6 

338.3 
100.9 

64.7 

129.4 

.7 

29.9 
82.0 
340.1 

95.0 
158.3 
612.9 



562.7 
259.2 
612.9 
374.9 
25.4 

....... 

Northern  Pacific  
Northwestern  Pacific  

1.5 

1.5 

236.2 
13.9 

372.4 
25  4 

.5 

1.0 

Pennsylvania  •'•  
Pennsylvania  Co  

5.0 

10.0 

242.3 

874,8 

10.0 
344.3 

21.2 
806.5 

906.0 
806.5 

Philadelphia,  Baltimore  &  Washington  

39.2 

121.7 

121.7 

Pittsburg,  Cincinnati,  Chicago  &  St.  Louis. 
West  Jersey  &  Seashore  

11.2 

29.2 

29.2 

93.4 

193.1 

193.1 

Pere  Marquette  

10  0 

10  0 

5.2 

5.2 

15.2 

Philadelphia  &  Reading  6  
Atlantic  City  

386.6 
86.9 

837.3 
173.8 

1.0 

2.0 

14.0 

20.1 

2.0 

857.4 
173.8 
6.4 
11.9 

"'28."8' 

Northeast  Pennsylvania  

4.6 

6.4 

Philadelphia,  Newtown  &  New  York  

7.1 

11.9 

Queen  &  Crescent  Route: 
'.  Alabama  Great  Southern  
Cincinnati,  New  Orleans  &  Texas  Pacific.. 
New  Orleans  &  Northeastern  

29.0 
35.3 

29.0 
35.3 

9.0 
56.6 

9.0 
56.6 

54.1 
240.2 
15.5 

54.5 
309.5 
31.0 

'"i'6 

""i'o 

92.5 
374.6 
31.0 

St.  Louis  &  San  Francisco  

3.9 

7.8 

596  2 

630  1 

630.1 
11.8 

7.8 

St.  Louis  Merchants'  Bridge  Terminal  

5.9 

11.8 

St  Louis  Southwestern  

.4 

4 

4 

San  Francisco,  Oakland  &  San  Jose  Consoli- 
dated   

3  9 

7  8 

7  8 

San  Pedro,  Los  Angeles  &  Salt  Lake  

1.1 

1.1 

1  ] 

Southern  

3.0 

6.0 

6  0 

Southern  Illinois  &  Missouri  Bridge  

4.6 

9.2 

9.2 

Southern  Pacific—  Atlantic  System: 
Galveston,  Harrisburg  &  San  Antonio    .  .  . 

279.1 

279  1 

279  1 

Louisiana  Western  

103.6 

103.6 

103.0 

Morgan's  Louisiana  &  Texas.,  

95  3 

95  3 

95  3 

Texas  &  New  Orleans  

109  8 

109  8 

109  8 

Southern  Pacific—  Pacific  System  
Staten  Island  Rapid  Transit  

1.0 
10.9 

1.0 
21.7 

6.0 

14.0 

2,348.1 

2,  508.  0 

2,  523.  0 
21  7 

Syracuse,  Lake  Shore  &  Northern  

6.5 

13.0 

13.0 

Terminal  R  .  R.  Association  of  St.  Louis  

6/0 
24.4 

12.0 
24.4 

12  0 

Ulster  &  Delaware  

24.4 

Union  

.6 

1.2 

1.2 

Union  Pacific  

8  9 

15  1 

1,381.5 
433.0 
566.8 
7  2 

1,  902.  1 
433.0 
592.5 
14  4 

33.3 

61.9 

1,979.1 
433.0 
602  9 

Oregon  R.  R.  &  Navigation  Co  
Oregon  Short  Line  

16  4 

16  4 

Wabash  

14  4 

Wabash  Pittsburg  Terminal  

4  1 

8  2 

8.2 

Washington  Terminal  

2  1 

20  4 

20.4 

Washington  Water  Power  Co  

29.0 

29  6 

29  0 

Western  Pacific  

11  2 

11  2 

11  2 

Total  

323.2 

536.  8 

1,920.9 

3,866.1 

433.  6. 

1,391.4 

14,167.6 

21,339.4 

919.1 

2,017.9 

23,058.9  !  6,092.7 

17,709.8 

29,151.6 

29,881 

closed  disk  signals  used  in  manual  block  territory  which  are  not  shown  in  Table  1 
signals  not  shown  in  this  table. 

4  (New  York  Central  &  Hudson  River.)    2 Smiles  4-frack,  u'ght°s7gnais,  not ;  shown  in  this  table.    The  apparent  discrepancy  in  road  mileage  in  this  table  is  due  to  the  fact  that  dif- 
ferent types  of  signals  are  used  on  the  different  tracks  of  4-track  sections  of  road. 

5  (Pennsylvania.)    5  miles  of  road,  28.2  miles  of  track  protected  by  light  signals  not  shown  in  this  table. 

«  (Philadelphia  &  Reading.)    Includes  15.3  miles  of  road  used  exclusively  for  freight  trains  not  shown  in  Table  1. 


THE    SIGNAL    DICTIONARY 


x 


METHODS  AND  APPARATUS  USED  WITH  MANUAL  BLOCK  SYSTEM 


Names  of  railroads. 

Telegraph. 

Telephone. 

Electric  bells. 

Controlled  manual. 

Electric  train 
staff. 

Block  signal 
stations. 

No  track  cir- 
cuit. 

Track    circuit 
at  stations. 

Continuous 
track  circuit. 

Miles  o 
road. 

Miles  of 
track. 

Miles  of 
road. 

Miles  of 
track. 

Miles  of 
road. 

Miles  of 
track. 

Miles  of 
road. 

Miles  of 
track. 

Miles  of 
road. 

Miles  of 
track. 

Miles  of 
road. 

Miles  of 
track. 

Miles  of 
road. 

Miles  of 
track. 

Total 
num- 
ber. 

Num- 
ber 
closed 
part 
time. 

Ann  Arbor  

1.4 

1.4 

2 

175 
115 
4 
2 
121 
292 
187 
3 
48 
2 
98 
7 
19 

38 

24 
57 
434 
19 

Atchison,  Topeka  &  Santa  Fe: 
Eastern  lines  ,  

7.7 
28.5 
4.3 
2.1 

7.7 
28.5 
4.3 
2.1 

51 
16 

841.9 

1,343.0 

Western  lines  '  

559.9 

561.1 

;  Coastlines  

.1  

Gulf,  Colorado  &  Santa  Fe  

""is 

8 
69 

P 

Atlantic  Coast  Line  *  

180.2 

223.4 

294.6 

346.6 

Baltimore  &  Ohio  
Baltimore  &  Ohio  Southwestern  

1,035.8 
960.0 

1,837.0 
1,001.9 

3.7 

3.7 

7.2 

7.2 

Baltimore  &  Sparrow's  Point  

4.7 

7.7 

Bessemer  &  Lake  Erie  

190.2 

320.6 

4.5 

4.5 

Boston  &  Maine  

4.8 

9.6 

Buffalo,  Rochester*  Pittsburg  

429.9 

558.7 

48 

Central  New  England  *  

14.7 

14.,7 

1.3 

1.3 

Central  of  Georgia  

59.7 

67.1 

3 

24 
5 
17 
262 

Chesapeake  &  Ohio  
Chesapeake  &  Ohio  -Ry.  of  Indiana  .  . 
Chicago^*  Alton  
Chicago  &  Eastern  Illinois  
Chicago  &  North  Western  
Chicago  &  Western  Indiana  

1,080.6 
269.0 

161.1 
1,801.7 

1,132.3 
269.0 

217.3 
1,812.5 

69.3 

18.7 
8.9 
722.9 

69.3 

18.7 
10.2 
827.4 

• 

9.5 

22.2 

139.4 

103.9 
61.4 

139.4 

103.9 
61.4 

74.2 

148.4 

28.9 

28.9 

7.7 
18.5 

7.7 
18.5 

Chicago  Great  Western  
Chicago,  Indianapolis  &  Louisville.  .. 
Chicago,  Milwaukee  &  St.  Paul  
Chicago,  Milwaukee  &  Puget  Sound 
Chicago,  Rock  Island  &  Pacific  
Chicago,  St.  Paul.  Minneapolis  &  Omaha... 
Cincinnati,  Hamilton  &  Dayton  

1,329.4 
525.0 
3,793.9 

190.2 
33.9 
99.0 

1,353.1 
525.0 
4,232.7 

190.2 
47.8 
99.0 

1,362.7 
988.7 
465.8 

1,3627 
988.7 
529.9 

1.5 

13.1 
2.0 
9.0 

1.5 

13.1 
2.0 
9.0 

213 
71 
629 
123 
143 
119 
10 
20 
2 
7 
6 
12 
4 
9 
9 
2 
302 
60 
3 
11 
14 
21 
57 
40 
8 

10» 
44 
273 
34 
33 
53 

Cincinnati,  Indianapolis  &  Western  .  .  . 
Colorado  Midland  

10 

2.0 

2.0 

Cornwall  &  Lebanon  

22.0 
7.3 

35.7 
13.3 

7 
3 

Cumberland  &  Pennsylvania  

* 

Cumberland  Valley  
Delaware,  Lackawanna  &  Western  

17.6 

17.6 

17.6 

17.6 

2.0 

2.0 

1.5 

1.5 

4.3 

4.3 

Duluth  &  Iron  Range  ,..    . 

16.2 
56.0 

17.6 
56.0 

8 

Durham  &  Southern. 

56.0 
11.3 

56.0 
11.3 

Elgin,  Joliet  &  Eastern  

Erie  

404.7 
248.8 

659.2 
257.2 

143.4 

259.3 

427.7 

589.6 

74 
8 
3 
5 
5 
1 
3 

Chicago*  Erie  

Columbus  &  Erie  

22.4 

32.2 

New  Jersey  &  New  York  

26.1 

26.1 

New  York,  Susquehanna  &  Western.  .  . 
EvansvUle  &  Terre  Haute  

34.7 

53.4 

108.5 

108.5 

Great  Northern  

239.8 

239  8 

18.7 

18.7 

Hocking  Valley  

144.0 

144.0 

Illinois  Central  

7  0 

12.0 

7.0 

12.0 

7.0 
24.0 

7.0 
24.0 

Illinois  Traction  ,  

Iowa  Central  

11.0 

11  0 

3 

2 
2 
8 
2 
3 
162 
37 
103 
2 
242 
3 
9 
10 
10 
42 
4 

39 
21 

209 
153 

216 

19 
22 
140 
639 
24 
15 

163 
214 
191 
35 
650 
33 
3 
15 
54 
198 
97 

288 
24 
88 
3 
8 
92 
14 
2 
12 
12 

2 

47 
19 
1 
32 
5 
11 
5 

Kan&wh*  At  Michigan      .  .      ... 

1.3 

1.3 

Kansas  City,  Clinton  &  Springfield  

2.5 

2.5 

Kentucky  &  Indiana  Bridge  &  R.  R.  Co.  .  . 

11,1 

17.9 

Kentwood  &  Eastern  

3.3 

3.3 

2 
2 

US 
10 
10 
2 
192 
1 
1 

Lackawanna  &  Wyoming  Valley  

1.2 

2.4 

2.2 
17.3 

3.4 

17.3 

LehighVallev  

697.0 

759.4 

Long  Island  *  

14  1 

28.2 

8  6 

17  2 

Louisville  &  Nashville  

438.2 

541.8 

57.7 

57.7 

Marquette  &  Southeastern  

3.7 

3.7 

Minneapolis,  St.  Paul  &  Sault  Ste.  Marie.  .  . 

396.3    2  400.7 

54.9 

54  9 

Missouri,  Kansas  &  Texas  

8.6  I        8.6 

Missouri  Pacific  

7.0 

14.0 

1.9 

1.9 

1.2 

1.2 

8.5 
4.7 

8.5 
4.7 

St.  Louis,  Iron  Mountain  &  Southern.. 

5.2 

5.2 

2.8 

4.4 

Mobile  &  Ohio.   .  . 

47  8 

47  8 

3 

Nashville,  Chattanooga  &  St.  Louis  

95.5 

107.3 

9.1 

9.1 

Newburgh  &  South  Shore  

6.2 

11.4 

4 

1 

17 

25 
112 
110 

17 
10 
74 
28& 
11 
& 
38 
120 
14 
29 
100 

New  York  Central  Lines: 
Boston  &  Albany  

1.9 

3.7 

Chicago,  Indiana  &  Southern  

203.7 

263.6 

Cleveland,  Cincinnati,  Chicago  &  St. 

572  6 

760  4 

351  9 

526.4 

Lake  Erie  &  Western.           

871.9 

880.9 

571.4 

580.4 

Lake  Shore  &  Michigan  Southern  

967.9 
90.5 

1,039.1 
90.5 

88.2 

88.9 

Dunkirk,  Allegheny  Valley  &  Pitts- 
burgh   

87  7 

87.7 

Michigan  Central  

920.3 

939.7 

New  York  Central  &  Hudson  River  
Peoria  &  Eastern  .  . 

,151.2 
86.5 

2,685.8 
89.0 

169.1 

338.1 

290.1 

586.5 

Pittsburg  &  Lake  Erie 

22.7 

25.6 

New  York,  New  Haven  &  Hartford 

201.3 

254.6 

227.2 

606,0 

1.0 

2.0 

6.3 

6.3 

Norfolk  &  Western  ... 

.010.1 

1.058.6 

281.3 

318.5 

Northern  Pacific  '  
Northwestern  Pacific  .  .  . 

587.2 
.199.2 

735.2 
199.2 

510.6 
51.3 

647.9 
51.3 



1.3 

1.3 

Pennsylvania  
Cleveland.  Akron  &  Columbus  

,147.4 
143.9 

1,799.8 
161.3 

,198.3 

1,948.7 

.8 

1.6 

14.7 

17.1 

Cincinnati  &  Muskingum  Valley 

11.4 

11.4 

!J  rand  Rapids  &  Indiana  

55.8 

55.8 

2.2 

4.4 

4 
11 
3 

13 

11 
14 
8 

Northern  Central... 

366  2 

546.1 

60.8 

61.8 

.7 

1.4 

Pennsylvania  Company. 

736.5 

1,066.4 

12.6 

18.1 

Philadelphia,  Baltimore  &  Washington. 
Pittsburg,  Cincinnati,  Chicago  &  St. 
Louis  

238.7 
,085  5 

391.  6 
1,772.8 

95.2 
8.1 

169.4 
15  8 

8.5 

8.5 

West  Jersey  &  Seashore  .  . 

79.6 

112.6 

.5 

.5 

Vandalia  

355  9 

416  8 

6.0 

6.0 

Peoria  <t  Pekin  Union  

6.0 

12.0 

Pere  Marquette  

39  0 

39  0 

1 

29 
12 
2 
8 
12 

38 
3 

13 

a 

11 
5 

Philadelphia  &  Reading  

236.9 

333.5 

.7 

7 

1.1 

1.1 

1.8 

2.1 

Atlantic  City'.... 

35  7 

35  7 

13  1 

13  1 

Northeast  Pennsylvania  

1.6 

1.6 

Perkiomen  

38.1 
35.9 

38.1 
35  9 

Reading  &  Columbia  

Queen  &  Crescent  Route. 
Cincinnati,  New  Orleans  &  Texas  Pacific 
Quincy,  Omaha  &  Kansas  City  and 
Iowa  &  St.  Louis  

.7 

.7 

305.0 

305.0 

R  ichmond  ,  Fredericksburg  &  Potomac  
St.  Joseph  &  Grand  Island.  

9.0 

9.0 

78.7 

157.4 

3 

.3 

St.  Louis  &  San  Francisco  

140  7 

140  7 

16.6 

16.6 

Beaumont,  Sour  Lake  &  Western... 

84.7 

84.7 

New  Orleans,  Texas  &  Mexico  

157  6 

157.6 

Orange  &  Northwestern  

61.6 

61.6 

'  (Atchison,  Topeka  &  Santa  Fe:  Western  lines.)    These  figures  include  18.7  miles  of  double-track  road  on  which  the  electric  train  staff  is  used  for  trains  moving  in  one  direction 
(down  grade),  and  the  simple  manual  block  system,  by  means  of  the  telephone,  for  trains  moving  in  the  opposite  direction.   ej, 
1  (Long  Island;  Atlantic  Coast  Line.)    A  number  of  these  offices  are  closed  several  months  during  the  year. 

» (Central  New  England.)    The  1.3  miles  on  which  the  electric  train  staff  system  is  used  is  worked  jointly  with  the  Poughkeepsie  City  &  Wappingers  Falls  Electric  Ry. 
<! i? ^»0,rtJ^nV.?acific^    Botn  the  telegraph  and  the  telephone  are  used  in  connection  with  the  block  system  on  105.6  miles  of  road. 
!  City.)    Both  the  telegraph  and  the  telephone  are  used  in  connection  with  the  block  system  on  13.1  miles  of  single  track. 


XI 


THE    SIGNAL    DICTIONARY 


METHODS  AND  APPARATUS  USED  WITH  MANUAL  BLOCK  SYSTEM  — Continued 


Names  of  railroads. 

Telegraph, 

Telephone. 

Electric  bells. 

Controlled  manual. 

Electric  train 
staff. 

Block  signal 
stations. 

No  "track  cir- 
cuit. 

Track    circuit 
at  stations. 

Continuous 
track  circuit. 

Miles  of 
road. 

Miles  of 
track. 

Miles  of 
road. 

Miles  of 
track. 

Miles  of 
road. 

Miles  of 
track. 

Miles  of 
road. 

Miles  of 
track. 

Miles  of 
road. 

Miles  of 
track. 

Miles  of 
road. 

Miles  of 
track. 

Miles  of 
road. 

Miles  of 
track. 

Total 
num- 
ber. 

Num- 
ber 
closed 
part 
time. 

St.  Louis  Merchants'  Bridge  Terminal 

1.1 

2.2 

3 
46 

381 
38 
6 

*     I 

2 
2 
28 
2 
6 
1 
2 
269 
9 

Seaboard  Air  Line  

206  6 
10.1 

206.0 
10.1 

6.9 

5.9 
98.0 

6.9 
5.9 
98.0 

16 

137 

Southern  

1,819.6 

2,  066.  9 

Southern  Pacific,  Pacific  System  

Spokane,  Portland  &  Seattle 

10.0 

20.0 

Staten  Island  

12.7 

22.8 

2 

Terminal  R.  R.  Association  of  St.  Louis 

1.1 

2.2 

Tidewater  Power  Co.8  

6.2 

6.2 

Toledo,  Peoria  &  Western  . 

.3 

.3 

Toledo,  St.  Louis  &  Western  

188.0 

188.0 

15 

Union  .... 

5 

5 

9 

9 

Union  Pacific  

11.4 

11.4 

Virginia  &  Kentucky  

.6 

.6 

Virginian  

2.2 

2.2 

W  abash  

1  ,  820.  7 

1,914.7 

116 

Washington  Southern  

32.2 

64.4 

Total  

38,612.7 

44,541.9 

12,198.8 

15,038.1 

485.8 

680.0 

1,802.8 

1,817.7 

483.9 

1,119.3 

439.4 

739.9 

345.6 

347.1 

•9,912 

3,751 

'  (Tidewater  Power  Co.)    Stafl  system  without  electric  control. 


PRACTICES  IN  THE  OPERATION  OF  THE  MANUAL  BLOCK  SYSTEM 


Names  of  railroads. 

Automatic  block  signals. 

Nonautomatic  block  signals. 

Total  auto- 
matic and 
nonautomatic. 

Total  passenger 
lines  operated. 

Percentage  block-signaled 
(miles  of  track). 

Single  track. 

Double  track. 

Three  track. 

Four  track. 

Total. 

Single  track.. 

Double  track. 

M 

Four  track. 

Total. 

i 

s, 

M 

T> 

1 

a1" 

Miles  of 
track. 

Miles  of 
road. 

Miles  of 
track. 

Miles  of 

Miles  of 

Miles  of 

Miles  of 

Ann  Arbor  

1.4 

1.4 

849.6 
565.7 
4.3 
2.1 

474.8 

1.4 

1,350.7 
589.6 
.4.3 
2.1 
576.5 

1.4 

928.9 
601.5 
242 
12.9 
490.0 
6.5 
1,264.8 
10.8 
974.0 
4.7 
194.7 
701.9 
13.8 
429.9 
7.9 

iao 

59.7 
212.4 
1,583.1 
269.0 
702.2 
329.8 
3,264.0 
27.3 
8,  734.  8 
1,456.4 
525.0 
3,916.6 
1,364.7 
1.3 
1,930.6 
32.6 
662.2 
68.2 
99.0 
2.0 
22.0 
7.3 
26.3 
410.0 
590.5 
16.2 
56.0 
16.3 
1,302.9 
248.8 
22.4 
42.3! 
36.6 
34.7 
105.8 
2.7 
389.3 
144.0 
7.3 
326.2 
6.6 

1.4 

1,503.6 
627.8 
25.2 
12.9 
603.8 
6.5 
2,278.0 
20.8 
1,029.9 
7.7 
325.1 
1,283.3 
27.6 
558.7 
7.9 
16.0 
67.1 
477.2 
1,892.0 
269.0 
847.1 
485.7 
4,  144.  5 
57.8 
9,  430.  3 
1,  545.  4 
525.0 
4,  459.  1 
1,364.7 
1.3 
2,  210.  2 
32.6 
732.4 
96.4 
99.0 
2.0 
35.7 
13.3 
33.0 
696.3 
1,  122.  1 
17.6 
56.0 
19.3 
1,992.1 
257.2 
32.2 
84.6 
47.1 
53.4 
105.8 
4.3 
511.0 
144.0 
15.6 
639.9 
6.6 

291.9 

2,519.0 
2,797.8 
1,825.5 
1,540.0 
3,832.4 
6.5 
3,  140.  5 
45.8 
980.1 
4.7 
191.8 
2,238.6 
13.8 
429.9 
25.3 
275.0 
1,915.9 
464.1 
1.607.4 
269.0 
998.9 
693.0 
6,894.0 
27.3 
8,421.5 
1,472.2 
579.1 
7,511.6 
1,364.7 
226.9 
6,682.7 
468.9 
1,468.1 
527.9 
360.9 
258.4 
22.0 
31.3 
162.2 
743.9 
922.1 
168.0 
56.0 
223.9 
1,706.5 
248.8 

Frei 
51.8 
208.4 
143.3 
686.6 
7,020.4 
336.6 
7.3 
4,  462.  7 
1,193.0 

291.9 

3,097.1 
2,824.1 
1,872.3 
1,540.0 
3,957.9 
6.5 
4,205.1 
73.0 
1,039.7 
7.7 
322.2 
2,801.6 
27.6 
558.  7 
25.3 
296.9 
1,915.9 
742.9 
1,916.3 
269.0 
1,143.0 
849.5 
7,806.0 
57.8 
9,171.2 
1,568.4 
579.1 
8,081.5 
1,364.7 
226.9 
6,974.4 
468.9 
1,553.4 
563.4 
360.9 
258.4 
35.7 
*     34.8 
207.0 
1,042.4 
1,  465.  9 
240.0 
56.0 
281.  6j 
2,395.7! 
257.2 
32.2 
ght  line. 
01.3 
227.1 
143.3 
1,014.9 
7,  142.  7 
375.5 
15.6 
5,027.2 
1,200.7 

0.4 

48.5 
22.2 
1.3 
.8 
15.1 
100.0 
542 
28.5 
99.0 
100.0 

45.8 
100.0 
100.0 
31.2 
5.7 
3.5 
64.2 
98.7 
100.0 
74.1 
57.2 
53.1 
100.0 
100.0 
98.5 
90.6 
55.2 
100.0 
.6 
31.6 
6.9 
47.2 
17.1 
27.2 
.8 
100.0 
38.2 
15.9 
55.1 
76.5 
7.3 
100.0 
6.8 
83.1 
100.0 
100.0 

76.6 
23.5 
73.8 
.4 
7.2 
38.3 
100.0 
12.7 
.6 

Atchison,  Topeka  &  Santa  Fe:  l 

5.7 
33.4 

73.6 
2.4 

79.3 
35.8 
19.9 
10.8 
15.2 
6.5 
218.1 
10.8 
14.0 

152.9 
38.2 
20.9 
10.8 
27.3 
6.5 
430.1 
20.8 
28.0 

361.4 
541.8 
43 
2.1 
373.1 

475.3 
23.9 

12.9 

18.9 
10.8 

1.0 

Atlantic  Coast  Line  

3.1 

12.1 

10L7 

Auburn  &  Northern  

6.5 
15.2 
.8 

l"98.  3 
10.0 

4.6 

363.6 

580.4 

87.0 

15.7 

1,046.7 

1,847.9 

14.0 

922.8 
1.7 

64.4 

35.0 
3.0 
130.3 
4.8 

2.2 

960.0 
4.7 
1947 
4.8 

1,001.9 
7.7 
325.1 
9.6 

Bessemer  &  Lake  Erie  2  

124.7 

570.3 

2.1 

697.1 
13  8 

1,273.7 
27  6 

Boston,  Revere  Beach  &  Lynn  

13.8 

301.2 

128.7 

429.9 

558.7 

7.9 

7  9 

7  9 

Central  New  England  

16.0 
52.3 

16.0 
59.7 

16.0 
67.1 

Central  of  Georgia  ;  . 

7.'4 

Central  of  New  Jersey  .... 

13.0 

165.5 

2.4 

31.5 

212  4 

477  2 

Chesapeake  &  Ohio  '  

Chesapeake  &  Ohio  Ry.  of  Indiana  

183.0 

183.0 

366.0 

1,274.2       125.9 
269.  0  

1,400.1 
269.  0 
141.2 
231.4 
2,  524.  6 
9.5 
8,  692.  0 
1,330.9 
525.0 
3,807.0 
1,364.7 

1,526.0 
269.0 
141.2 
288.9 
2,  639.  9 
22.2 
9,333.1 
1,354.6 
525.0 
4,245.8 
1,364.7 

Chicago  &  Alton  

416.1 

144.9 
98.4 
719.6 
17.8 
35.4 
64.9 

"is."  8 
""i.'e 

""e.'o 

561.0 
9S.4 
739.4 
17.8 
42.4 
125.9 

706.9 
196.8 
1,  504.  6 
35.6 
97.2 
190.8 

141.2 
173.9 
2,409.3 

"  8,"  676."  8 
1,307.2 
525.  0 

57.5 
115.3 
6.3 

602.7 
23.7 

1/1 

1.4 

Chicago  &  North  Western  
Chicago  &  Western  Indiana  

Chicago  Great  Western  .".  "  
Chicago  ,  Indianapolis  &  Louisville  

61.0 

Chicago,  Milwaukee  &St.  Paul 

5.9 

103.7 

109.6 

213.3    3.368.2        438.8 

Chicago,  Milwaukee  &  Puget  Sound  

|  1.364.7  

1 

Chicago,  Peoria  &  St.  Louis  Ry.  of  Illinois. 
Chicago,  Rock  Island  &  Pacific  

Chicago,  Rock  Island  &  Gulf 

1.3 
653.3 
32.6 

1.3 

.      1.3  

279.6 

932.9 
32  6 

1,212.5 
32  6 

997.7 

997.7 

997.7 

Chicago,  St.  Paul,  Minneapolis  &  Omaha.. 
Cincinnati,  Hamilton  &  Dayton 

20.6 

6.2 
14  3 

6.2 
34.3 

12.4 

48.6 

591.9 
20.0 
99.0 

64.1 
13.9 

..:... 

656.0 
33.9 
99.0 
2.0 
22.0 
7.3 
19.6 

16^2 
56.0 
11.3 
1,075.8 
248.8 
22.4 

720.1 
47.8 
99.0 
2.0 
35.7 
13.3 
19.6 

""5.8 
17.6 
56.0 
11.3 
1,508.1 
257.2 
32.2 

Cincinnati.  Indianapolis  &  Western.. 

Colorado  Midland  

2.0 

Cornwall  &  Lebanon  

8.3 

13.7 

Cumberland  &  Pennsylvania  

4.3 

3.6 

Cumberland  Valley                     

6.7 

6  7 

13.4 

19.6 

Delaware  &.  Hudson  

163.1 
104.7 

225.1 
435.1 

4.3 
38.3 

17.5 
6.6 

410.0 
584.7 

696.3 
1,116.3 

14^8 

Duluth  &  Iron  Range  

1.4 

Durham  &  Southern 

56.0 

2.0 

3  0 

5.0 
227.1 

8.0 
484.0 

11.3 
643.5 
240.4 
12.6 

Erie  

212.2 

14.9 

432.3 
8.4 
9.8 

, 

Chicago  &  Erie 

Erie  &  Jersey 

42  3 

42  3 

84.6 

New  Jersey  &  New  York  

10.5 

10.5 

21.0 

26.1 
10.0 

is.7 

26.1 
34.7 
105.8 

20.1 
53.4 
105.8 

Evans\7ille  &  Terre  Haute  

105.8 

Grand  Trunk 

1  l 

1  6 

2  7 

4.3 

Great  Northern  

Hocking  Valley 

8.5 

122.3 

130.8 

253.1 

258.5 
144.0 

258.5 
144.0 

258.5 
144.0 

Hudson  &  Manhattan* 

7  3 

7.3 

15.6 

Illinois  Central  5  

Yazoo  &  Mississippi  Valley  

65.1 
6.6 

235.1 

12.0 

312.2 
6.6 

620.9 
6.6 

9.0 

5.0 

14.0 

19.0 

1  (Atchison,  Topeka  &  Santa  Fe. )    On  this  road  automatic  signals  are  used  to  protect  short  sections  of  track  in  manual  block  territory,  aggregating  80.7  miles  of  track. 

2  (Bessemer  &  Lake  Erie.)    These  figures  include  8.9  miles  of  road  on  which  no  passenger  trains  are  run. 

3  (Chesapeake  &  Ohio.)    Includes  Coal  River. 

«  (Hudson  &  Manhattan.)    Light  signals,  not  shown  in  Table  2. 

5  (Illinois  Central;  New  York,  New  Haven  &  Hartford;  Pennsylvania;  Washington  Terminal.)    Include  road  with  more  than  4  tracks. 


THE    SIGNAL    DICTIONARY 


XII 


PRACTICES  IN  THE  OPERATION  OF  THE  MANUAL  BLOCK  SYSTEM  — Continued 


Names  of  railroads. 

Permissive  signal- 
ing forbidden. 

Permissive  signaling  allowed. 

Rear-end    protec- 
tion only. 

Stop  at  station  rec 
ognized    as   stop 
for  signal   oppo- 
site office. 

By  three-position 
signal. 

By     two-position 
signal  and   flag 
or  lantern. 

By  caution  card. 

Miles  of 
road. 

Miles  of 
track. 

Miles  of 
road. 

Miles  of 
track. 

Miles  of 
road. 

Miles  of 
track. 

Miles  of 
road. 

Miles  of 
track. 

Miles  of 
road. 

Miles  of 
track. 

Miles  of 
road. 

Miles  of 
track. 

172.7 

381.1 

i«2,131.5 
'«  143.9 
»»1!  4 

3,202.1 
161.3 
11.4 

55.8 
278.8 
1,084  5 

157.3 

185.8 

33.8 

48.6 

143.9 
11.4 
55.8 

161.3 
11.4 
55.8 

2.2 
15.3 

4.4 

21.2 

55.8 
}  «  152.  4 
1  »  749.  1 

749.1 

1:084.5 

Philadelphia,  Baltimore  &  Washington  

'  *  333.  9 
n,l02.  1 

561.0 
1,797.1 

Plttsburg,  Cincinnati,  Chicago  &  St.  Louis  

1,102.1 

1,797.1 

•80.1 

113.1 

6.0 

6.0 

i  »  355.  9 
»6.0 

416.8 
12.0 

355.9 

416.8 

Peoria  &  Pekin  Union             

39.0 
28.8 
35.7 
1.6 

39.0 
47.5 
35.7 
1.6 

3Q  0 

39.0 

Philadelphia  &  Reading                           .  .. 

i  '211.7 

289.9 

Atlantic  City          

Northeast  Pennsylvania  

Perkiomen  

'  '  38.  1 
i  »  35.  9 

'.7 

305.0 
1*87.7 

38.1 
35.9 

.7 

305.0 
166.4 

Queen  &  Crescent  Route: 
Cincinnati,  New  Orleans  &  Texas  Pacific  

Quincy,  Omaha  &  Kansas  City  and  Iowa  &  St. 

305.0 

305.0 

305.0 

305.0 

Richmond,  Fredericksbure  &  Potomac  

'.3 

.3 

157.3 

157.3 

Beaumont,  Sour  Lake  &  Western  

'84.7 
'157.  6 
»61.6 

84.7 
157.6 
61.6 

Orange  &  Northwestern  

St.  Louis  Merchants'  Bridge  Terminal  

1.1 

2.2 

6.9 

10.1 
98.0 

6.9 
10.1 
98.0 

'206.6 
31,819.6 

206.6 
2,006.9 

Spokane,  Portland  &  Seattle  

10.0 

20.0 

10.0 
12.7 

20.0 
22.8 

Staten  Island  

'  12.7 
1.1 

22.8 
2.2 

»  12.7 

22.8 

Terminal  R.  R.  Ass'n  of  St.  Louis  . 

Toledo,  St.  Louis  <t  Western  

•188.0 

188.0 

Toledo,  Peoria  &  Western 

.3 
1.4 

.5 
.6 
2.2 

.3 
1.4 
.5 
.6 
2.2 

* 

10.9 

10.9 

Virginia  &  Kentucky  

Virginian  

Wabash          .                                 . 

1,820.7 

1,914.7 

769.1 

769.1 

Total... 

6,  526.  4 

8.378.2 

23.323.0 

28.498.7 

1.674.6 

1.972.3 

23.471.5 

25.856.9 

11,455.4 

11,641.3 

23,579.4 

26,878,7 

1  Permissive  signaling  is  practiced  only  In  the  case  of  a  freight  train  following  a  freight  train,  or  in  similar  movements  where  neither  train  carries  passengers. 
'By  dispatcher, 
a  By  rule. 


WIRE-CIRCUIT  BLOCK  SIGNAL  SYSTEMS  ON  ELECTRIC  INTERURBAN  RAILWAYS 


Names  of  companies. 

! 

Miles  of 
road 
equipped. 

Names  of  companies. 

Miles  of 
road 
equipped. 

63.8 

172.7 
7.1 
26.6 
9.0 
12.8 
14.8 
.3 

8.3 
25.9 
2.7 

New  Hampshire  electric  railways—  Continued. 
Haverhill  &  South  New  Hampshire  

7.8 
8.1 
26.9 
12.5 
3.1 
14.4 
11.2 
16.7 
85.4 

Haverhill,  Plaistow  &  Newton  

p..      .   „    il   J  Y.       R    'i            f  w     hinpton  " 

ronnprtip   t                                                               

Portland  Railway  Light  &  Power  

New  Hampshire  electric  railways: 
Amesbury  &  Hampton  

Trenton  Bristol  &  Philadelphia                                .             Tx  

Western  New  York  &  Pennsylvania  Traction  

Haverhill  &  Amesbury  

Total  

530.1 

DICTIONARY  OF 
WORDS,   TERMS    AND    PHRASES     USED 

RAILWAY  SIGNALING 

Page  and  Figure  Numbers  in  the  Dictionary 

Refer  to  the  Section  of 
Descriptions  and  Illustrations. 


IN 


A 

A,  C.    Abbreviation  for  Alternating  Current. 

A.  R.  A.  Abbreviation  for  American  Railway  Associa- 
tion. 

'Absolute  Block  Signaling.  The  rigid  adherence  to  the 
fundamental  principle  of  the  block  system  that  no 
train,  be  admitted  to  a  block  while  another  train 
occupies  it.  See  Permissive  Block  Signaling. 

Accumulator.  A  word  sometimes  applied  to  a  current 
accumulator  or  storage  battery.  See  Figs.  2250- 
2264. 

Active  Current.  A  working  component  of  a  current  in 
an  alternating  current  circuit  as  distinguished  from 
a  wattless  component  of  current.  The  component 
of  an  alternating  current  which  is  in  phase  with 
the  impressed  electromotive  force. 

Adjustable  Crank.     See  Figs.  1172-1173. 
Adjustable  Lock  Rod.     See  Figs.  1522-1527. 

Adjusting  Screw.  A  device  in  a  pipe  or  wire  line  used 
for  changing  its  length,  as  in  case  of  wires  subject 
to  expansion  and  contraction  due  to  changes  of 
temperature.  See  Figs.  1026-1046,  1307-1308. 

Admittance.  The  reciprocal  of  the  impedance  in  an 
alternating  current  circuit.  The  apparent  conduct- 
ance of  an  alternating  current  circuit  or  conductor. 

Advance  (adjective).  In  an  advanced  position,  as  a 
signal,  as  related  to  the  train  for  which  such  signal 
is  used.  A  train  approaching  a  station  which  has  a 
distant,  a  home,  and  an  advance  signal,  encounters 
first  the  distant,  then  the  home,  and  then  the  ad- 
vance. The  distant  is  in  the  rear  of  the  home,  and 
the  home  is  in  the  rear  of  the  advance  signal. 

Advance  Block  Signal.  A  fixed  signal  used  in  connec- 
tion with  the  home  block  signal  to  subdivide  the 
block  in  advance. 

Function.  To  govern  movements  of  all  trains  on  main 
tracks,  and  of  all  trains  moving  from  sidings  to 
main  tracks  between  home  and  advance  block  sig- 
nals into  block  ahead.  To  provide  for  closing  in 
trains. 

Location.  Governed  by  consideration  of  consistent 
and  convenient  operation.  If  the  advance  block  sig- 
nal is  located  close  ahead  of  the  trailing  switch  of  a 
passing  siding,  the  front  end  of  a  long  train  must 
pass  this  signal  in  order  to  back  in  on  the  siding. 
If  an  unlock  has  been  received  it  would  then  be 
taken  up  unless  a  special  circuit  arrangement  were 
provided  to  prevent  it.  If  the  unlock  has  been 
taken  up  the  following  train  must  be  carded.  If  the 
engine  and  first  part  of  a  train  are  permitted  to 
pass  an  advance  block  signal  indicating  stop,  when 
making  such  a  switching  movement,  the  absolute 
stop  indication  of  the  signal  is  violated,  introducing 


an  inconsistency  in  the  operation.  If  the  advance 
block  signal  is  located  a  sufficient  distance  ahead  of 
the  trailing  switch  nearest  to  it,  so  a  train  backing 
in  will  not  have  to  pass  the  signal,  its  location  will 
be  in  some  cases  3,500  ft.  from  the  block  station, 
and  if  the  signal  fails  to  clear  after  the  train  reaches 
it,  or  after  the  train  has  passed  the  home  signal, 
serious  delay  results. 

Advance  Signal.  A  signal  having  the  same  function  as 
a  home  signal,  placed  some  distance  in  advance  of 
the  home  signal  at  a  block  or  interlocking  signal 
station,  providing  in  effect  a  short  block  section 
in  which  the  signalman  may  hold  a  train  while  not 
interfering  with  the  movement  of  trains  in  the  main 
block  section,  either  in  advance  or  in  the  rear.  He 
can  accept  another  train  in  the  rear  block  as  soon 
as  the  arriving  train  has  passed  completely  beyond 
his  home  signal,  and  he  can  hold  the  arriving  train 
at  the  advance  signal  until  the  block  in  advance  is 
clear.  In  Great  Britain  a  signalman  is  forbidden, 
except  under  rigid  restrictions,  to  authorize  a  train 
to  proceed  toward  his  station  from  the  station  in 
the  rear,  unless  the  last  preceding  train  has  passed 
beyond  his  starting  signal;  or,  if  there  is  no  such 
signal,  until  it  has  passed  1,320  ft.  (%  mile)  be- 
yond his  home  signal.  The  restriction  is  that  he 
must  give  to  the  rear  station  a  special  authoriza- 
tion, "section  clear,  but  station  or  junction  blocked," 
and  this  information  must  be  given  to  the  engine- 
man  by  word  of  mouth.  See  Figs.  314,  318,  766-769, 
787. 

Advance  Starting  Signal.  (British.)  See  Starting  Sig- 
nal. 

Air  Gap.  The  space  between  the  ends  of  the  poles  of 
an  electro-magnet  and  the  armature  of  the  magnet. 
Any  break  occupied  wholly  by  air  in  a  magnetic 
circuit. 

Alligator  Jaw.    See  Escapement  Crank. 

"All  Right."  An  oral  signal  commonly  given  by  a  con- 
ductor to  an  engineman,  meaning  proceed  to  the 
next  station  or  regular  stopping  place;  used  also, 
loosely,  in  speaking  of  the  "proceed"  indication  of 
a  fixed  signal.  In  British  practice  the  oral  signal, 
"right  away,"  has  a  meaning  similar  to  the  Ameri- 
can "all  right." 

Alternating  Current.  A  current  of  electricity  which 
flows  alternately  in  opposite  directions,  its  magni- 
tude varying  from  maximum  in  one  direction 
through  zero  to  maximum  in  the  opposite  direction 
and  back  again  according  to  the  laws  of  simple  har- 
monic motion,  as  distinguished  from  continuous  or 
Direct  Current,  which  see.  A  complete  change 
from  any  value  to  the  corresponding  value 
in  the  opposite  direction  and  back  again  is 
called  an  alternation  or  cycle,  and  the  number 
of  such  alternations  in  a  second  is  called  the 


THE   SIGNAL  DICTIONARY 


Alt-Ano 


frequency  of  the  current.  In  commercial  applica- 
tions frequency  usually  varies  between  25  and  120 
cycles  per  second.  Two  alternating  currents  equal 
in  magnitude  and  frequency  may  not  attain  equal 
values  simultaneously.  The  interval  between  the 
assuming  of  a  given  value  by  one  current  and  of 
the  same  value  by  the  other  current  is  called  the 
phase  difference  between  the  two.  It  is  usually 
spoken  of  in  terms  of  the  angular  difference  be- 
tween the  rotating  parts  generating  the  two  cur- 
rents. Referred  to  a  given  current,  another  cur- 
rent which  passes  through  stated  values  ahead  of 
the  reference  current  is  said  to  lead,  and  onef  which 
reaches  these  values  after  the  reference  current  is 
said  to  lag.  A  single  alternating  current  consists  of 
two  single  phase  currents  flowing  in  opposite  di- 
rections at  a  given  instant,  a  three-phase  current 
consists  of  three  currents  a  third  of  a  cycle  apart, 
four-phase,  four  currents  a  quarter  of  a  cycle  apart, 
and  so  on  for  any  number  of  phases.  The  value  of 
an  alternating  current,  which  is  commonly  used  in 
referring  to  it,  is  not  the  maximum  value  it  reaches, 
but  a  value  equal  in  magnitude  to  that  of  a  direct 
current  which  would  produce  the  same  heating  ef- 
fect. This  value  is  I_  or  .707  times  the  maximum 

V2 
value. 

Alternating  Current  Relay.  A  relay  designed  to  re- 
spond to  alternating  current.  See  Figs.  608-609,  680- 
684,  696,  3087,  3103. 

Alternation.  A  change  in  direction.  A  change  or  re- 
versal in  the  direction  of  an  electromotive  force  or 
current.  A  single  vibration  or  oscillation  as  dis- 
tinguished from  a  complete  cycle  or  double  vibra- 
tion. 

Alternator,  or  Alternating  Current  Generator.  One 
which  produces  alternating  currents,  either  single- 
phase  or  polyphase. 

American  Wire  Gauge.  The  name  generally  given  to 
the  Brown  and  Sharpe  wire  gauge,  in  which  the 
largest  wire,  No.  oooo,  has  a  diameter  of  .46  in., 
the  smallest  wire,  No.  36,  .005  in.,  and  all  other 
diameters  are  in  geometrical  progression. 

Ammeter.  An  instrument  for  measuring  in  terms  of 
amperes,  the  current  flowing  in  an  electrical  cir- 
cuit. It  consists  of  a  fixed  coil  of  heavy  wire  carry- 
ing the  current  to  be  measured  and  a  pivoted  mag- 
netic core,  to  which  is  attached  a  pointer  sweeping 
over  a  fixed  scale.  The  force  tending  to  displace 
this  core  from  its  normal  position  varies  with  the 
current  passing  through  the  coil  and  is  resisted  by 
some  opposing  force  (usually  gravity,  a  spring, 
or  a  powerful  permanent  magnet),  which  brings  the 
pointer  into  a  new  position  of  equilibrium  for  each 
value  of  the  current.  See  Figs.  3515,  3520,  3523, 
3525,  3526.  3528,  3529,  3534- 

Ampere.  The  practical  unit  of  measurement  of  electric 
current  or  the  rate  of  flow.  Such  a  current  as  will 
pass  with  an  electromotive  force  of  one  volt 
through  a  circuit  of  one  ohm  resistance.  The 
analogy  of  water  flowing  through  a  pipe  will  make 
this  clear.  That  which  causes  the  water  to  flow 
is  the  pressure  or  head;  that  which  resists  the 
flow  is  the  friction  of  the  water  against  the  pipe, 
and  the  rate  of  flow  may  be  represented  by  so  many 
cubic  inches  of  water  per  second.  Electrically,  the 
pressure  corresponds  to  electromotive  force,  the 
friction  to  resistance  and  the  quantity  per  second  or 
the  number  of  amperes  to  the  rate  of  flow.  As  the 


pressure  increases  the  flow  increases  proportion- 
ally; as  the  resistance  increases  the  flow  decreases. 
The  relation  between  amperes,  volts  and  ohms  is 

E 
represented  by  Ohm's  law,  1=  — ,  in  which  I  is  the 

R 

current,  R  the  resistance  and  E  the  electromotive 
force.  The  standard  of  measurement  for  an  ampere 
is  such  a  current  as  will  deposit  4.024  grammes  of 
silver  in  one  hour  on  one  of  the  plates  of  a  silver 
volt-ammeter  from  a  solution  of  silver  nitrate  con- 
taining from  15  to  30  per  cent  of  the  salt. 

Ampere-hour.  A  unit  of  electrical  quantity  equal  to  the 
quantity  of  electricity  conveyed  by  one  ampere 
flowing  for  one  hour.  A  quantity  of  electricity 
equal  to  3,600  coulombs. 

Ampere-hour  Meter.  An  instrument  giving  the  total 
time  integral  of  the  amperes. 

Ampere  Turn.  A  unit  of  magneto-motive  force  equal 
to  that  produced  by  one  ampere  flowing  around  a 
single  turn  of  wire. 

Angle  Bar.  A  term  used  to  denote  a  common  form  of 
fastening  used  to  connect  together  and  hold  in  line 
the  ends  of  two  rails  which,  placed  end  to  end, 
form  a  part  of  a  railway  track.  A  modification  of 
the  fish  bar,  or  fish  plate.  * 

Angle  Cock.  In  an  automatic  air-brake  system,  the 
stopcock,  one  at  each  end  of  each  car,  by  which, 
when  a  car  is  to  be  detached  from  the  train,  the 
compressed  air  in  the  train  pipe  of  that  car  is  con- 
fined. The  undesired  automatic  application  of  the 
brakes  is  thereby  prevented.  In  a  train  made  up 
for  operation  every  angle  cock  except  that  at  the 
extreme  rear  of  the  train  and  that  at  the  front  of 
the  engine  must  be  open.  The  accidental  closing" 
of  such  a  cock,  by  cutting  off  the  engineman's  con- 
trol of  the  brakes  in  that  part  of  the  train  in  the 
rear  of  the  closed  cock,  may  cause  disaster. 

Angle  of  Lag.  The  angular  difference  in  position  of 
a  point  on  a  curve  representing  values  of  an  alter- 
nating current  behind  the  corresponding  point  on 
a  curve  representing  other  values  of  the  same  cur- 
rent or  the  same  values  of  another  current.  An 
angle  whose  tangent  is  equal  to  the  ratio  of  the 
inductive  to  the  ohmic  resistance  and  whose  cosine 
is  equal  to  the  ratio  of  the  ohmic  resistance  to 
the  impedance  in  the  alternating  current  circuit. 

Angle  of  Lead.  The  angular  difference  in  position  of 
a  point  on  a  curve  representing  values  of  an  alter- 
nating current  ahead  of  the  corresponding  point 
on  a  curve  representing  other  values  of  the  same 
current  or  the  same  values  of  another  current.  Op- 
posed to  angle  of  lag,  which  see. 

Anion.  The  electro-negative  ion  or  radical  of  a  mole- 
cule. 

Annunciator.  A  device,  audible  or  visual,  to  announce 
the  approach  of  a  train.  Visual  annunciators  are 
either  of  the  drop  type  or  of  the  same  general  form 
and  appearance  as  indicators;  see  Figs.  2550-2629. 
Audible  annunciators  are  usually  electric  bells.  See 
Approach  Indicator. 

Anode.  The  conductor  or  plate  of  a  decomposition 
cell  connected  with  the  positive  terminal  of  a  bat- 
tery or  other  electric  source.  The  terminal  of  an 
electric  source  out  of  which  the  current  flows  into 
the  electrolyte  of  a  decomposing  cell,  or  volt- 
ammeter.  In  an  electrolyte  cell,  bath,  or  receptive 


Ans-Ave 


device,  the  terminal  at  which  the  current  enters, 
as  distinguished  from  the  cathode,  at  which  the 
current  leaves. 

Answer  Back.  A  circuit-interrupting  device  used  with 
electric  selectors  or  signals  in  a  selective  telephone 
or  telegraph  train  dispatching  or  signal  system,  so 
arranged  as  to  indicate  over  the  telephone  or  tele- 
graph circuit  to  the  dispatcher  the  operation  of  the 
bell  or  signal  at  the  desired  station.  See  pages 
126-132.  ' 

Apparent  Efficiency.  The  efficiency  of  a  generator, 
motor,  or  other  apparatus  in  an  alternating  cur- 
rent circuit  which  equals  the  ratio  of  net  power 
output  to  volt-ampere  input. 

Apparent  Electromotive  Force.  The  E.M.F.  apparently 
acting  in  a  circuit  as  measured  by  the  drop  of  pres- 
sure due  to  the  resistance  of  the  circuit  and  the 
current  strength  passing  through  it. 

Apparent  Power.  In  an  alternating  current  circuit,  the 
apparent  watts,  or  the  product  obtained  by  multi- 
plying the  volts  by  the  amperes,  as  read  directly 
from  a  voltmeter  and  ammeter. 

Apparent  Resistance.  The  impedance  of  an  alternat- 
ing current  circuit  containing  both  resistance  and 
reactance.  The  quotient  obtained  from  dividing 
voltage  by  current  in  such  a  circuit. 

Approach  Indicator.  A  block  indicator  for  an  approach 
locking  or  other  track  circuit. 

Approach  Locking.  Electric  locking  effected  by  the 
approach  of  a  train,  the  train  actuating  a  track- 
circuit  relay  or  a  track  instrument.  The  arrange- 
ment is  such  that  the  levers  are  locked  as  soon  as 
a  train  approaches  the  signals;  that  is,  while  it  is 
yet  some  distance  away,  as  one  or  two  miles.  If 
an  approaching  train  by  this  means  locks  switches 
and  then  is  stopped  and  detained  and  does  not  use 
the  route,  the  signalman  can  unlock  his  levers  by 
closing  the  unlocking  circuit  by  means  of  a  "time 
release."  The  releasing  device  is  arranged  to  en- 
force deliberation  (and  thus  prevent  errors)  by 
an  automatic  time  device;  by  a  slow-moving  circuit 
closer  operated  by  making  a  number  of  turns  of 
a  screw;  or  by  a  hand  switch  fixed  in  some  in- 
accessible place,  requiring  some  time  for  the  sig- 
nalman to  get  to  it.  Thus  the  signalman  will  be 
prevented  from  hastily  taking  away  a  route  which 
has  been  set  up  for  an  approaching  train.  Ap- 
proach locking  may  be  used  for  only  one  or  two 
movements  through  an  interlocking,  or  it  may  be 
expanded  to  cover  any  possible  movement.  Typical 
approach  locking  circuits  are  shown  and  explained 
in  Figs.  2055-2068,  2073.  See  Screw  Release,  Lock. 
Electric,  Time  Release. 

Arm.  The  principal  movable  part  of  a  semaphore,  con- 
sisting of  a  blade  of  wood  or  metal,  fastened  to  a 
casting,  which  turns  on  the  supporting  pivot.  See 
Figs.  229,  etc.,  and  Figs.  3224-3478. 

Arm  Casting.  That  part  of  a  semaphore  arm  which 
contains  the  bearing  and  the  spectacles  for  holding 
the  glasses  which  give  the  night  color  indications. 
To  it  is  fastened  the  blade.  See  Figs.  3224-3478. 

Armature.  A  mass  of  iron  or  other  magnetizable  ma- 
terial placed  on  or  near  the  pole  or  poles  of  a 
magnet.  In  .the  case  of  a  permanent  magnet  the 
armature  may  be  of  soft  iron,  placed  directly  on  the 
magnetic  poles,  in  which  case  it  preserves  or  keeps 


the  magnetism  by  closing  the  lines  of  magnetic 
force  of  the  magnet  through  the  soft  iron  of  the 
armature.  It  is  then  called  a  keeper.  In  the  case 
of  an  electromagnet  the  armature  is  placed  near 
the  poles  and  is  moved  toward  them  whenever  the 
magnet  is  energized  by  the  passage  of  the  current 
through  the  magnetizing  coils.  This  movement  is 
made  against  the  action  of  a  spring  or  gravity,  so 
that  on  the  loss  of  magnetism  by  the  magnets,  the 
armature  moves  from  the  magnetic  poles.  When 
the  armature  is  of  soft  iron  it  moves  toward  the 
magnet  on  the  completion  of  the  circuit  through 
its  coils,  no  matter  in  what  direction  the  current 
flows,  and  is  then  called  a  non-polarized  or  neutral 
armature.  When  made  of  steel  or  of  another 
electromagnet  it  moves  from  or  toward  the  poles 
according  to  whether  the  poles  of  the  armature  are 
of  the  same  or  of  a  different  polarity  from  these 
of  the  magnet.  Such  an  armature  is  called  a  polar- 
ized armature  (Houston).  The  term  armature  is 
applied  to  the  rotor  or  stator  of  a  motor  or  gen- 
erator. See  Magnet. 

Arm  Sweep.  The  segment  of  a  circle  defining  the 
limits  of  the  movement  of  a  semaphore  signal 
arm. 

Asbestos.  A  hydrous  silicate  of  magnesia,  i.  e.,  silicate 
of  magnesia  combined  with  water.  A  fireproofing 
material  sometimes  used  by  itself  or  in  connection 
with  other  material  for  insulating  purposes. 

Automatic  Block  Signal.  A  block  signal,  worked  by 
electric  or  pneumatic  agency,  which  is  controlled 
by  the  passage  of  a  train  into,  through  and'out  of 
the  block  section  to  which  the  signal  is  connected. 
The  entrance  of  a  train  sets  the  home  signal  at 
stop,  and  the  clearing  of  the  block  section  by  the 
passage  of  the  train  out  of  it  sets  that  signal  clear. 
The  apparatus  is  so  arranged  that  the  misplacement 
of  a  switch  or  the  accidental  entrance  of  a  car 
from  a  side  track  will  set  the  signal  at  stop.  See 
Track  Circuit,  Distant  Signal. 

Automatic  Block  Signal  System.  A  series  of  consecu- 
tive blocks.  Automatic  block  signals  were  invented 
and  developed  in  America,  the  first  installation 
being  16  miles  of  the  Eastern  Railroad  of  Massa- 
chusetts (now  the  Boston  &  Maine)  equipped  with 
automatic  signals  in  1871.  These  signals  were  con- 
trolled by  Track  Instruments,  which  see.  In  1879 
the  Track  Circuit,  which  see,  was  introduced  as  a 
method  of  control  on  10  miles  of  the  Fitchburg 
Railroad,  and  is  now  universally  used  in  automatic 
signaling. 

Automatic  Circuit-Breaker.  A  device  for  automatically 
opening  a  circuit  when  the  current  passing  through 
it  is  excessive. 

Automatic  Stop.  An  apparatus,  mechanical  or  electro- 
magnetic, for  stopping  trains  by  means  actuated 
from  outside  the  train  (as  at  a  signal  post).  In  the 
simplest  form  a  trip,  fixed  on  the  roadway  and 
moving  in  unison  with  the  usual  visual  signal,  is 
made  to  open  an  air  valve  on  the  engine,  or  car, 
thereby  applying  the  powe'r  brakes  or  shutting  off 
the  propelling  power,  or  both,  independently  of  the 
engineman  or  motorman.  See  Figs.  653,  658,  667, 
668,  669,  675,  686-688,  701,  703-709,  3691-3700. 

Average  Efficiency  of  Motor.  The  efficiency  of  an  elec- 
tric motor  based  on  its  average  or  mean  load.  The 
ratio  of  all  the  work  that  a  motor  delivers  in  a 


THE   SIGNAL  DICTIONARY 


B-Blo 


given   time   to  the  electric  energy  it  has  absorbed 
in  that  time. 

B 

B.    &    S.      Abbreviation    for    Brown    &    Sharpe's    wire 

gauge. 
B.  W.  G.     Abbreviation  for  Birmingham  wire  gauge. 

Back  Contact.  (Of  a  relay.)  An  electric  contact  which 
is  made  by  the  armature  of  a  relay  when  it  falls 
away  from  the  pole  piece  of  the  magnet  coils  con- 
sequent on  the  cessation  of  the  current  flowing 
through  the  coils.  See  Relay  and  Front  Cbntact. 

Back  Electromotive  Force.  A  term  sometimes  used 
for  counter  electromotive  force. 

Back  Light.  A  small  glass-covered  opening  in  the  back 
of  a  signal  lamp.  It  is  to  enable  the  signalman 
to  keep  watch  of  the  light  and  be  assured  that  it  is 
always  burning.  The  back  light  (spectacle)  on  the 
semaphore  arm,  usually  carries  a  purple  glass,  so 
arranged  that  when  the  signal  is  at  stop  the  back 
light  shows  purple,  and  when  it  is  not  in  that 
position  the  back  light  shows  white. 

Back  Locking.  The  mechanical  locking  in  a  "Stand- 
ard" interlocking  machine,  which  acts  in  the  same 
plane  as  the  tappets.  See  Figs.  851-902. 

Back  Spectacle.  A  small  casting  containing  a  roundel 
at  one  end  and  fastened  at  the  other  to  the  sema- 
phore shaft  of  a  signal  in  such  a  manner  as  to 
change  the  visible  color  of  the  back  light,  which 
see,  by  passing  before  it.  Sometimes  instead  of 
carrying  a  roundel  the  back  spectacle  is  solid  or 
carries  a  disk  of  metal  to  obscure  the  back  light. 
See  Figs.  3472-3476. 

Back  Wire.  The  wire  connected  to  the  back  tail  lever 
of  an  interlocking  machine  to  pull  a  signal  to  the 
stop  position.  Used  to  insure  that  the  movements 
of  the  signal  arm  shall  follow  the  movements  of  the 
lever.  Sometimes,  especially  in  Europe,  only  one 
wire  (the  pulling  wire,  which  see)  is  used. 

Balance  Lever.  The  lever  which  carries  the  signal 
counterweight.  See  ig-igA,  and  26,  Figs.  1639- 
1646,  and  14,  Figs.  1672-1675. 

Balanced  Circuit.  A  telephonic,  telegraphic  or  other 
circuit  which  has  been  so  erected  and  adjusted  as 
to  be  free  from  mutual  inductive  disturbances  from 
neighboring  circuits. 

Balancing  Relay.    A  differentially  wound  relay. 

Banjo  Signal.  A  common  name  for  the  Enclosed  Disk 
Signal,  which  see.  So  called  because  in  general 
appearance  it  resembles  a  huge  banjo. 

Banner  Signal.  A  common  name  for  the  Clockwork 
Signal,  which  see. 

Basket.  A  term  sometimes  applied  to  a  Switch  Adjust- 
ment, which  see. 

Basket  Rod.  A  term  sometimes  applied  to  a  Throw 
Rod,  which  see. 

Battery.  A  source  of  electricity.  See  Primary  Battery; 
Storage  Battery.  See  Figs.  2243-2351. 

Battery  Chute.  A  small  receptacle  for  batteries,  de- 
signed to  be  set  in  the  ground  below  frost  level 
in  order  to  prevent  freezing  of  the  battery.  Chutes 
are  usually  circular  or  oval  and  may  hold  one  or 
two  tiers  of  batteries.  They  are  commonly  made 
of  cast  iron  and  sometimes  of  reinforced  concrete 


or  fibre.     See  also  Well  and  Vault.     See  Figs.  2370- 
2387,  2394-2399. 

Battery  Jar.  A  jar  provided  for  holding  the  electro- 
lyte of  each  of  the  separate  cells  of  a  primary  or 
secondary  battery.  See  Figs.  2256-2261,  2276,  2278,. 
2281-2283,  2323-2325,  2329,  2330-2334,  2337-2349. 

Bell  Code.  A  code  in  which  are  set  forth  the  number 
of  strokes  of  an  electric  bell  to  be  sounded  to  give 
each  of  the  necessary  station-to-station  communi- 
cations in  manual  block  signaling.  See  Manual 
Block  System. 

Bell  Crank.     See  Crank. 

Bell,  Electric.  A  bell  actuated  by  electromagnets. 
Used  for  long-distance  communication  and  to  an- 
nounce trains  either  at  a  cabin  or  a  highway  cross- 
ing. See  Manual  Block  System,  Controlled  Man- 
ual Block  System,  Highway  Crossing  Signal,  Tele- 
graph Block  System.  See  Figs.  2146-2231. 

Binding  Post.  A  terminal  of  metal  to  which  a  wire 
may  be  attached  to  make  an  electric  connection. 
The  wire  is  usually  clamped  in  place  by  a  set  of 
nuts  screwed  to  a  threaded  projection  on  the  post, 
or  is  inserted  in  a  hole  and  held  in  place  by  a  screw 
entering  the  post  at  right  angles  to  the  wire  hole. 
See  Fig.  2358. 

Bipolar.     Having  two  poles. 

Blade.  A  signal  arm  consists  of  a  spectacle  casting 
and  a  blade.  The  blade  may  be  of  wood  or  metal 
and  is  of  various  shapes  and  painted  with  various- 
stripes  to  indicate  the  function  of  the  signal,  as 
distant,  home,  interlocking  or  automatic.  The 
blade  is  the  extended  part  of  the  arm  which  gives 
the  day  indications.  See  Figs.  225-228,  3341-3343, 
3361-3369. 

Blade-Grip.  That  part  of  a  semaphore  arm  or  spec- 
tacle which  is  formed  to  receive  the  blade  and  to 
which  the  blade  is  fastened. 

Blind  Siding.  A  familiar  term  for  a  side  track  situated 
at  a  place  where  there  is  no  station  agent  and  no- 
telegraph  office. 

Block  (noun).  A  length  of  track  of  defined  limits,  the 
use  of  which  by  trains  is  governed  by  block  signals. 
The  common  name  for  a  block  section. 

Block  Indicator.  An  electromagnetic  device  (in  a 
signal  cabin)  controlled  by  a  track  circuit  to  in- 
dicate to  the  signal  man  whether  or  not  that  track 
circuit  is  occupied  by  a  train.  The  electromagnet, 
actuated  directly,  or  through  a  relay  by  the  track 
circuit,  has  on  its  armature  a  miniature  semaphore 
arm,  the  movements  of  which  give  the  indications. 
See  Figs.  2550-2629. 

Block  Instrument.  The  instrument  used  in  controlled 
block  signaling  to  compel  the  co-operation  of  the 
signalmen  at  both  ends  of  the  block  in  allowing  a 
train  to  enter  from  either  end.  The  arrangement 
is  such  that  this  can  be  done  only  when  the  block 
is  clear.  See  Figs.  346-405. 

Block  Section.  A  section  of  track  of  defined  length, 
the  use  of  v/hich  by  trains  is  regulated  by  a  fixed 
signal  at  the  entering  end;  or,  on  a  single  track 
l<ne,  by  such  signals  at  both  ends.  See  Figs.  314- 
324- 

Block  Signal.  A  fixed  signal  at  the  entrance  to  a 
block  section  used  to  give  indications  regulating 
the  movement  of  trains  into  that  section.  If  there 


Blo-Blo 


THE  SIGNAL  DICTIONARY 


is  a  switch  immediately  in  advance  of  the  signal  it 
may  be  an  interlocked  signal  also.  See  Home 
Signal. 

Block  Signaling  for  Maximum  Traffic.  The  conditions 
that  determine  the  length  of  a  block  section  and 
consequently  the  number  of  tiains  that  may  be  run 
in  a  given  time  are: 

(1)  The  speed. 

(2)  The   braking   power   and   consequent   distance 
required  in  which  to  stop  a  train  running  at  maxi- 
mum speed. 

(3)  The  grade  of  the  track. 

(4)  The   time  required  for  the   signals   to  change 
from    the    position   indicating   "Stop"   to   that   indi- 
cating "Proceed." 


home  signal  is  the  length  of  the  shortest  block  that 
may  be  used  with  safety. 

The  speed  of  a  train  is  affected  by  gravity  assist- 
ing or  retarding  its  motion  according  to  the  grade 
of  the  track.  Any  force  affecting  the  speed  of  the 
train  will  have  a  corresponding  effect  on  the  brak- 
ing power,  and  the  length  of  the  block  must  there- 
fore be  proportioned  to  the  grade. 

The  length  of  time  required  for  a  signal  to  chang; 
from  the  stop  to  the  proceed  position  has  an  im- 
portant bearing  on  the  efficiency  of  a  signal  system 
and  the  consequent  spacing  of  trains.  The  time 
required  for  a  signal  to  assume  the  clear  position 
is  only  a  few  seconds;  but,  as  the  home  signal  does 
not  commence  to  clear  until  the  train  has  passed 


T/me   -Spacing  of  Trains 
l'30"  2  2'3O'  3' 


e 
33O 


430 


(^     The  length  of  the  train. 

(6)  The  position  of  interlocking  plants,  stations 
and  other  local  conditions  which  cause  an  irregular 
spacing  of  the  signals. 

The  number  of  trains  that  may  be  run  in  a  given 
time  is  dependent  on  the  speed.  The  greater  the 
speed  the  greater  the  number  of  trains  that  may  be 
run.  To  provide  for  a  maximum  train  service  it 
must  be  possible  to  run  trains  at  the  greatest  speed 
local  conditions  permit,  and  the  blocks  must  be  of 
such  length  as  to  allow  this  speed  to  be  attained 
with  safety. 

To  run  a  train  safely  at  a  given  speed  it  is  nec- 
essary to  keep  the  engineman  informed,  at  al) 
times,  of  the  condition  of  the  track  in  front  of  him 
and  if  it  is  proper  for  the  train  to  proceed.  If  it  is 
not  safe  to  proceed  the  engineman  must  be  warned 
at  a  point  sufficiently  far  away  from  the  stopping 
point  to  enable  him  to  bring  the  train  to  a  stop 
before  passing  it.  The  higher  the  speed  the  greater 
the  distance  from  the  stopping  point  the  indication 
to  stop  or  to  proceed  must  be  given. 

The  distant  indication  is  given  by  the  distant 
signal,  and  it  is  therefore  necessary  that  this  signal 
be  placed  far  enough  from  the  home  signal  to  en- 
able a  train  to  be  brought  to  a  stop  in  the  distance 
between  the  two  signals.  The  braking  power  then 
becomes  as  importaftt  an  element  in  determining 
the  length  of  the  block  for  a  maximum  train  serv- 
ice under  safe  working  conditions  as  are  the  factors 
of  speed  and  grade.  With  good  practice  demand- 
ing that,  as  a  regular  thing,  the  indication 'of  a 
home  signal  shall  be  repeated  by  one  and  not  by 
two  distant  .signals,  it  follows  that  for  the  average 
conditions  the  distance  between  the  distant  and  the 


out  of  the  block,  the  next  following  train  is  delayed, 
while  the  home  and  the  distant  signals  are  clear- 
ing. The  practical  result  is  the  same  as  if  the 
block  had  been  lengthened  the  distance  the  train 
will  run  in  the  time  the  two  signals  are  clearing.  A 
maximum  train  service  requires  a  minimum  time  for 
the  clearing  of  the  signals.  A  change  from  one 
second  to  five  seconds  in  the  time  required  to  clear 
a  signal — lengthening  the  time  four  seconds — will 
reduce  by  10  per  cent  the  number  of  trains  it  is 
possible  to  run  when  the  speed  is  60  miles  an  hour 
and  the  length  of  block  equal  to  the  braking  dis- 
tance. 

The  length  of  a  train  will  affect  the  number  it 
is  possible  to  run  in  a  given  time,  for  the  signals  do 
not  commence  to  clear  until  the  rear  of  the  train 
has  passed  out  of  the  block.  The  train  must  run- 
its  length,  in  addition  to  the  length  of  the  block,, 
before  the  signals  will  clear  for  the  following  train. 
Trains  running  at  speed  are  spaced  the  length  of 
the  train,  plus  the  length  of  the  block,  plus  the 
distance  between  the  distant  and  the  home  signals, 
for  with  the  short  blocks  necessary  for  a  maximum 
train  movement  the  application  of  the  brakes  at  the 
distant  signal,  as  will  be  necessary  if  the  signal, 
when  passed,  is  indicating  caution,  will  reduce  the 
speed  so  materially  that  trains  will  be  spaced  a 
greater  distance  than  if  they  were  run  far  enough 
apart  to  get  a  clear  indication  at  each  distant  signal. 

The  position  of  interlocking  plants,  stations  and 
similar  local  conditions,  the  situation  of  which  is 
fixed  and  cannot  be  changed  to  permit  of  the  best 
placing  of  signals,  will  affect  somewhat  the  time- 
spacing  of  trains.  Where  the  interlocking  and  sta- 
tion signals  occur  at  such  intervals  that  the  blocks 


THE   SIGNAL  DICTIONARY 


Blo-Bre 


are  of  equal  length,  the  regular  spacing  of  trains 
can  be  maintained,  but  where  the  blocks  are  of  un- 
equal length  trains  will  be  kept  further  apart  and 
the  situation  must  be  carefully  studied.  At  those 
places  where  the  blocks  will  be  shorter  than  the 
required  distances  between  the  distant  and  the 
home  signal  the  indication  of  the  home  signal  must 
be  repeated  by  two  distant  signals,  and  the  furthest 
of  the  two  is  likely  to  be  found  a  greater  distance 
from  the  home  signal  than  the  necessary  braking 
distance,  thus  giving  an  indication  so  far  away  that 
the  train  may  be  stopped  some  time  before  reach- 
ing the  home  signal. 

Having  the  information  at  hand  in  regard  tf>  lay- 
out of  tracks,  grades,  curvature,  station  locations, 
etc.,  it  is  necessary  before  the  signals  can  be  located 
on  the  plan  that  an  assumption  be  made  as  to  the 
maximum  speeds  which  trains  will  be  allowed  to 
attain  on  the  different  parts  of  the  line.  The  ac- 
companying chart  shows,  in  minutes  and  seconds, 
at  the  top  of  the  diagram,  the  necessary  time  in- 
terval between  trains  at  various  speeds,  with  block 
signals  fixed  at  different  distances  apart,  as  shown 
at  the  left  of  the  diagram.  The  length  of  a  train 
is  assumed  to  be  520  ft.,  and  provision  is  made  for 
having  at  all  times  two  home  signals  in  the  stop 
position  behind  a  train.  (This  is  to  provide  for  an 
overlap,  as  is  done  on  the  New  York  City  subway 
and  the  New  York  Central  Electrified  Lines.) 
Therefore,  to  give  each  train  a  clear  distant  signal, 
the  time  intervals  between  trains  must  be  equal  to 
the  time  required  to  run  three  times  the  length  of 
one  block,  plus  the  length  of  the  train,  plus  the 
distance  run  during  the  time  (assumed  to  be  -4 
seconds)  required  for  the  home  and  the  distant 
signals  to  move  from  the  stop  to  the  clear  position, 
plus  a  sufficient  time  for  an  approaching  engineman 
to  see  conveniently  the  distant  signal,  say  20  sec- 
onds. W.  H.  E. 

Block  Sheet.  At  a  block-signal  station,  the  sheet  on 
which  the  movements  of  trains  are  recorded. 

Block  Station.  A  place  from  which  manual  block  sig- 
nals are  operated.  On  important  lines  the  block 
station  is  generally  a  "tower" — that  is,  a  two-story 
building,  with  the  signal  levers  and  telegraph  in- 
struments in  the  second  story. 

Block  System.  "A  series  of  consecutive  blocks" 
(A.  R.  A.).  The  method  of  regulating  the  move- 
ment of  railway  trains,  so  as  to  maintain  an  in- 
terval of  space  between  trains  moving  in  the  same 
direction  (on  the  same  track).  It  was  first  used  on 
double-track  lines,  where  a  given  track  is  used 
wholly  by  trains  moving  in  one  direction,  but  it  is 
equally  applicable  to  single-track  lines  used  by 
trains  moving  in  both  directions.  Given  a  line  with 
stations,  A,  B,  C,  D,  etc.,  a  train  is  held  (blocked) 
at  A  until  the  last  preceding  train  has  arrived  at 

B,  and  at  B  until  the  preceding  train  has  arrived  at 

C,  and   so   on.      Thus  the   normal    "space   interval" 
between    trains    following   one    another   is    the    dis- 
tance   between    stations;    but    the    minimum    space 
is  the  thickness  of  the  signal  post,  except  as  modi- 
fied by  the  overlap  (which  see)  in  automatic  block 
signaling  and  by  rigid  rules  of  procedure  in  man- 
ual   block    signaling.       Signalmen    are    usually    re- 
quired to  see  that  the  rear  end  of  a  train  has  passed 
300  ft.  beyond  the  home  signal   (say  at   B)   before 
giving  permission  to  A  to  send  on  another  train. 
This  gives  300  ft.  leeway  as  a  provision  against  the 


danger  of  a  train  running  past  a  stop  signal  and 
striking  the  rear  of  a  preceding  train  which  has 
been  stopped  immediately  after  entering  a  block 
section.  The  rules  also  require  that  if  a  train  is  un- 
expectedly stopped  the  rear  trainman  shall  go  back 
with  hand  signals  to  stop  any  following  train.  The 
block  system  was  first  used  in  England,  about  1842. 
It  was  first  used  in  America  on  the  line  between 
Kensington  (Philadelphia),  Pa.,  and  Trenton,  N.  J., 
about  1863.  In  1872,  when  the  Pennsylvania  took 
over  this  and  other  lines  in  New  Jersey,  the  aggre- 
gate length  of  these  lines  worked  by  the  space 
interval  was  90  miles.  The  simplest  form  of  the 
block  system  is  the  Manual  Block  System,  which 
see.  Other  forms  are  the  Controlled  Manual  Block 
System,  Electric  Train  Staff  and  Automatic  Block 
Signal  System. 

Bolt  Lock  (verb).  To  control  a  switch  by  means  of  a 
bolt  lock. 

(noun).  A  lock  at  a  switch,  consisting  of  a  bolt 
controlled  by  the  pipe  or  wire  that  operates  the 
signal,  which  is  used  to  permit  trains  to  pass  over 
that  switch,  so  arranged  that  if  the  switch  is  not  in 
proper  position  the  signal  connection  cannot  be 
moved  to  clear  the  signal.  See  Figs.  1710-1725. 

Bond.     See  Rail  Bond. 

Bond  Wire.     See  Rail  Bond. 

Bonding  Plug.  A  piece  of  metal,  somewhat  like  a  rivet, 
used  to  fasten  a  wire  to  a  rail.  See  Channel  Pin. 
See  Figs.  3594-3627. 

Bonding  Tube.  A  tapered  iron  or  steel  tube,  coated 
with  tin  or  copper,  and  having  a  longitudinal  slit 
for  fastening  a  bond  wire  to  a  rail.  It  is  of  the  same 
general  size  and  is  used  for  the  same  purpose  as  a 
Channel  Pin,  which  see.  See  Figs.  3594-3627. 

Bootleg.  On  track-circuit  connections,  a  short  piece  of 
wooden  trunking,  conduit,  or  conduit  encased  in 
concrete,  enclosing  the  wire  leading  from  the  rail 
down  to  the  horizontal  part  of  the  wire  which 
leads  to  the  battery  box  or  the  relay  box.  The  term 
is  also  sometimes  used  to  include  the  wire  itself. 
See  Figs.  3722-3772,  3851-3883. 

Box  Crank.  Two  or  more  cranks  assembled  in  a  com- 
mon frame,  each,  crank  having  an  independent 
bearing.  See  Figs.  1154-1160. 

Box  Wheel.  A  group  of  chain  wheels  mounted  in  one 
frame.  See  Figs.  1371-1386.  , 

Boxing.  Wooden  covering  for  pipe  or  wire  lines.  Used 
to  exclude  dirt  or  to  prevent  persons  from  stepping 
on  the  pipe  or  wire;  also  used  to  enclose  pipe  01 
wire  lines  when  laid  beneath  streets. 

Bracket  Mast.  The  upright  above  the  crosspiece  of  a 
bracket  signal  structure.  See  Figs.  3224-3273,  3282- 
3285. 

Bracket  Post.  An  arrangement  for  supporting  two  or 
more  signals,  side  by  side,  on  a  single  foundation. 
See  Figs.  3224-3273,  3302-3305. 

Break-down  Switch.  A  panel  switch  employed  in  small 
three-wire  systems,  for  connecting  the  positive  and 
negative  bus-bars  so  as  to  convert  the  system  int'> 
a  two-wire  system,  and  thus,  in  case  of  a  break- 
down, to  permit  the  system  to  be  supplied  with 
current  from  a  single  dynamo. 

Breaking  Down  of  Insulation.  The  failure  of  an  in- 
sulating material,  as  evidenced  by  the  disruptive 
passage  of  an  electric  discharge  through  it. 


Bri-Cap 


THE   SIGNAL  DICTIONARY 


Bridge  Circuit  Controller.  A  device  for  connecting  and 
disconnecting  circuits  at  a  drawbridge  actuated  by 
the  same  lever  that  moves  the  bridge  lock  or  un- 
*  couples  the  pipe  lines,  or  by  a  separate  lever  when 
the  bridge  is  set  in  position  (and  locked),  or  when 
it  is  unlocked.  See  Figs.  2538-2549. 

Bridge  Coupler.  The  coupling  at  the  end  of  a  draw- 
bridge in  a  pipe  line,  which  extends  from  a  cabin  on 
the  drawbridge  to  a  function  not  on  the  draw- 
bridge, or  vice  versa,  designed  to  be  quickly  dis- 
engaged when  the  bridge  is  to  be  opened  and 
quickly  engaged,  when  the  bridge  is  again  closed. 
See  Figs.  1739-1744. 

Bridge  Lock.  A  device  for  locking  a  drawbridge  in  its 
closed  position,  so  interlocked  with  the  signals  ap- 
proaching the  bridge  that  they  cannot  be  cleared 
unless  the  bridge  is  in  proper  position  and  locked. 
See  Figs.  1742-1751. 

Bridge  Mast.  The  upright  on  a  signal  bridge.  See 
6,  7,  Figs.  3224-3263,  and  Figs.  3274-3277. 

Bridging  Coils.  In  telephony,  coils  which  are  con- 
nected across  a  telephone  circuit,  as  distinguished 
from  coils  placed  in  series  in  the  circuit. 

Bridle  Rod.     See  Front  Rod. 

Brushes  of  Dynamo-electric  Machines.  Strips  of  metal, 
bundles  of  wire  or  wire  gauze,  slit  plates  of  metal, 
or  plates  of  carbon,  that  bear  on  the  commutator 
cylinder  of  a  dynamo,  and  carry  off  the  current 
generated. 

Buffer.     See  Dash  Pot. 

Bus  Bar.  On  a  switchboard  or  other  terminal,  a  com- 
mon conductor,  usually  a  rectangular  copper  bar, 
from  which  taps  may  be  made  for  connecting  up 
recording  instruments,  such  as  ammeters,  watt- 
meters, etc.,  or  for  taking  off  current  for  local  cir- 
cuits. 

Butt  End.  A  term  applied  to  a  jaw  or  bar  whose  end 
is  cut  off  without  tang  or  thread.  See  Figs.  1047- 
1133- 

Butt  Strap.  An  iron  block,  riveted  to  a  tie  plate,  which 
see,  to  take  the  side  thrust  of  the  rail  through  a  rail 
brace,  which  see. 

Butting  Collision.  A  collision  between  meeting  trains 
- — trains  moving  toward  each  other  on  the  same 
track. 

Buzzer,  Electric.  A  call,  not  as  loud  as  that  of  an 
electric  bell,  employing  a  humming  sound  by  the 
use  of  a  sufficiently  rapid  automatic  contact- 
breaker.  A  telephone  receiver  for  Morse  circuits 
employing  a  vibrating  contact  key. 

c 

C.  M.     Abbreviation  for  Circular  Mil. 

C.  R.  Abbreviation  for  Cold  Rolled.  Used  in  connec- 
tion with  steel  and  iron. 

Cab  Signal.  A  signal  in  the  cab  of  a  locomotive.  The 
term  is  used  to  include  all  arrangements  for  pro- 
ducing visual  or  audible  indications  on  moving  en- 
gines or  cars  by  means  of  mechanical,  electrical  or 
magnetic  devices  situated  on.  at  the  side  of  or 
above  the  roadway,  and  producing  effects  on  mov- 
ing vehicles.  Such  devices  have  not  come  into 
general  use  and  have  been  tried  on  but  few  rail- 
ways. See  Automatic  Stop. 

Cabin.     A  common  name  for  a  signal  tower,  which  see. 


Cable  Box.  A  box  provided  for  the  reception  and 
protection  of  a  cable  head. 

Cable,  Electric.  An  electrical  conducting  wire,  or,  more 
commonly,  a  collection  of  such  wires,  embedded 
in  an  insulating  covering.  Cables  are  used  to  con- 
duct electric  currents  beneath  rivers,  as  at  draw- 
bridges; for  connections 'from  poles  to  offices  or 
cabins,  or  in  any  situation  where  a  multiplicity  of 
separate  wires  is  objectionable,  or  where  the  con- 
ductors must  be  protected  from  gases,  or  other 
injurious  substances,  and  in  electric  interlocking 
for  connections  from  cabins  to  switches  and  sig- 
nals, usually  under  ground.  See  Figs.  3919-3924. 

Cable  Head.  A  rectangular  board  provided  with  bind- 
ing posts  and  fuse  wires  for  the  purpose  of  re- 
ceiving the  wires  of  overhead  lines  where  they  enter 
a  cable. 

Cable  Tracer.  One  of  the  wires  in  a  cable  marked  in 
such  a  manner  as  to  be  readily  distinguishable  from 
the  other  wires  and  used  in  tracing  circuits  through 
the  cable. 

Cage.  A  term  sometimes  applied  to  a  Switch  Adjust- 
ment, which  see. 

Cage  Rod.     A  term  sometimes  applied  to  a  Throw  Rod. 

which  see. 

Calling-On  Arm.  A  semaphore  signal  arm  used  to  au- 
thorize a  train  to  move  (toward  the  signal  cabin) 
past  a  home  signal  when  the  principal  arm  of  the 
signal  has  to  be  left  at  "stop"  because  the  block 
section  is  not  clear  or  because  for  any  reason  it 
would  not  be  allowable  to.  permit  the  train  to  pass 
the  signal  unconditionally.  The  calling-on  arm  is 
usually  smaller  than  the  standard  semaphore  arm, 
and  is  placed  below  the  standard  size  arm  or  arms. 
In  England  the  calling-on  arm  is  common,  and  it 
is  rapidly  finding  favor  in  America.  On  the  Penn- 
sylvania the  term  has  been  applied  to  the  dwarf- 
size  arms,  which  are  used  on  full-size  posts  (or  on 
bridges)  in  the  scheme  for  "speed  signaling"  which 
has  been  introduced  in  connection  with  three-p^>si- 
tion  signals  for  interlocking,  and  which  is  illus- 
trated in  Figs.  265-276.  In  this  scheme  the  small 
lower  arm  is  inclined  to  the  45-deg.  position  to 
give  the  "calling-on"  indication.  Besides  this  indi- 
cation that  speed  is  to  be  controlled,  the  function 
of  the  arm  is  limited  by  the  rules,  which  say  that 
it  is  to  be  used  only  for  low  speed  routes.  Being 
thus  limited,  the  calling-on  arm  can  be  used,  for 
example,  to  move  a  train  (or  part  of  a  train)  past 
a  home  signal,  forward,  on  the  main  line,  to  be 
coupled  to  the  rear  of  a  train  which  is  stopped  a 
short  distance  in  advance. 

Cantilever  Bracket  Post.  A  substitute  for  a  bracket 
post.  See  Figs.  3224-3263,  in  which  the  cantilever 
signal  14  is  a  substitute  for  and  conveys  the  same 
information  as  the  bracket  signal  21;  likewise  18 
may  be  substituted  for  27.  See  Bracket  Post. 

Capacity  Circuit.  A  circuit  containing  capacity  but  no 
inductance. 

Capacity  of  Cable.  The  quantity  of  electricity  required 
to  raise  a  given  length  of  cable  to  a  given  potential, 
divided  by  the  potential.  In  a  multiple  cable,  the 
amount  of  charge  at  unit  potential  which  any  sin- 
gle conductor  will  take  up,  the  rest  of  the  con- 
ductors being  grounded.  The  ability  of  a  con- 
ducting wire  or  cable  to  permit  a  certain  quantity 


8 


THE   SIGNAL  DICTIONARY 


Cap-Cir 


of  electricity  to  be  passed  into  it  before  acquiring 
a  certain  potential. 

Capacity  of  Line.  The  ability  of  a  line  to  act  as  a 
condenser,  and,  therefore,  like  it,  to  possess  capac- 
ity. 

Capping.     Covering  for  Trunking,  which  see. 

Cathode.  The  conductor  or  plate  of  a  decomposi- 
tion cell  connected  with  the  negative  terminal 
of  a  battery  or  other  electric  source.  The  ter- 
minal of  an  electric  source  into  which  the  cur- 
rent flows  from  the  electrolyte  of  a  decomposi- 
tion cell  or  voltmeter.  The  electrode  of  a  bath, 
tube,  body  or  device  by  which  the  current  Reaves 
the  same.  The  negative  electrode. 

Caustic  Soda  Battery.  A  primary  battery  using  caustic 
soda  solution  for  the  electrolyte. 

Caution  Card.  In  block  signaling  a  written  order  is- 
sued by  a  signalman  to  authorize  a  train  to  enter 
a  block  which  is  not  clear.  See  Permissive  Block 
Signaling.  Form  B,  of  the  Standard  Code  of  the 
American  Railway  Association,  is  shown,  reduced 
in  size,  below: 


COMPANY. 


Block  Station ,     M 190 

to  ENOINEMAN.  train  No on track. 

Block  is  not    clear.      You  may  proceed    witn    caution   expecting    to    find    track 
obstructed. 


.Signalman 


Enginemen  receiving  this  card  properly  filled  'out  and  signed  by  the  signalman, 
may  proceed  with  the  train  under  control  prepared  to  itop  short  of  any  obstruction 
in  the  block. 

[PRINT  NAME.] 


.Superintendent. 


Another  form  (Form  D)  is  used  when  the  com- 
municating wire  from  station  to  station  is  broken 
or  otherwise  unavailable. 

Caution  Signal.  A  signal  indication  denoting  that  a 
train  may  proceed  under  some  restriction  usually 
(in  permissive  block  signaling)  with  the  under- 
standing that  a  preceding  train  moving  in  the  same 
direction  may  be  overtaken  at  any  point  in  the 
block  section,  and  that  therefore  the  speed  must  be 
very  low,  except  as  the  engineman  is  able  to  see  a 
clear  track  for  a  considerable  distance  ahead.  Thus, 
on  a  long,  straight  track,  in  clear  weather,  "cau- 
tionary" speed  is  not  necessarily  low  speed.  "Cau- 
tion" is  used,  but  with  a  different  meaning,  as  the 
name  of  the  indication  of  a  distant  signal  which 
says  "proceed,"  expecting  to  find  the  next  home 
signal  indicating  stop.  As  the  home  signal  referred 
to  may  be  a  mile  or  more  away  the  distant  signal 
does  not  require  speed  to  be  reduced  or  limited  at 
any  specific  point,  the  reduction  or  limitation  must 
be  applied,  wherever  it  may  be  necessary  in  order  to 
•  insure  a  stop  at  the  home  signal.  If,  when  the 
home  signal  is  seen,  it  proves  to  have  been  put  in 
the  clear  position,  the  "caution"  indication  at  once 
becomes  void. 

Cell.     One  unit  of  an  electric  battery. 

Centimeter.     The  hundredth  of  a  meter;  or,  0.3937  inch. 

Chain  Wheel.  A  grooved  wheel  about  10  in.  in  diame- 
ter, mounted  in  vertical  or  horizontal  bearings, 
about  which  ]^-'\n.  chain  is  passed  to  change  the 


direction  of  a  signal  wire  line.  For  a  short  dis- 
tance a  chain  is  used  in  place  of  the  wire  and  the 
chain  is  guided  by  the  groove  in  the  rim  of  the 
wheel.  See  Figs.  1338-1408. 

Chain  Wheel  Stand.  A  casting  carrying  one  or  more 
chain  wheels.  A  one-way  chain  wheel  stand  carries 
one  wheel;  a  two-way  stand  carries  two  wheels. 

Channel  Pin.  A  device  used  to  fasten  a  wire  to  a  rail; 
a  truncated  cone,  in  which  is  cut  a  longitudinal  slot 
of  radius  equal  to  that  of  the  wire.  The  pin  is  in- 
serted in  a  hole  in  the  rail  with  the  wire  and  driven 
home,  thereby  wedging  the  wire  firmly  in  place. 
See  Figs.  3603-3609,  3613,  3615. 

Charging  Current.  The  current  employed  in  charging 
a  storage  battery  or  accumulator. 

Check  Lock  Lever.  In  an  interlocking  machine,  a 
separate  lever  which  is  used  for  Check  Locking, 
which  see.  Also  called  traffic  lever.  See  Figs. 
2079,  2082. 

Check  Locking.  A  method  of  interlocking  electric- 
ally the  levers  in  two  adjacent  interlocking  plants 
to  permit  train  movements  to  be  made  against 
the  current  of  traffic.  In  electric  and  electro-pneu- 
matic interlocking  plants  there  is  usually  provided 
in  each  tower  a  separate  lever  for  each  track  over 
which  reverse  movements  are  to  be  made.  These 
levers  are  connected  with  the  mechanical  locking 
in  such  a  way  that,  when  they  are  in  their  normal 
position,  the  signal  for  reverse  movements  is  locked 
in  the  stop  position  and  the  signal  for  movements 
with  the  current  of  traffic  is  free  to  be  moved. 
When  both  check  lock  levers  are  reversed  the 
signal  for  normal  movements  is  mechanically 
locked  in  the  stop  position  and  the  dwarf  signal 
(for  reverse  movements)  at  the  adjacent  interlock- 
ing is  unlocked  to  allow  reverse  movements.  See 
Figs.  2079-2082. 

Choke  Coil.  A  reactance  used  in  connection  with  light- 
ning arresters  and  placed  in  series  with  the  line 
to  be  protected. 

Chute.     See  Battery  Chute. 

Circuit  Breaker.  A  switch,  controlling  an  electric  cir- 
cuit, which  normally  is  closed.  See  Figs.  2416- 
2549- 

Circuit  Closer.  A  switch,  controlling  an  electric  cir- 
cuit, which  normally  is  open.  See  Figs.  2416-2549. 

Circuit  Controller.  A  switch,  push-button,  plug,  or  any 
similar  means  for  conveniently  opening  and  closing 
an  electric  circuit.  See  Figs.  2416-2549. 

Circuit,   Electric.     See  Electric   Circuit. 

Circuit,  Multiple.  A  compound  circuit  in  which  a 
number  of  separate  sources  or  separate  electro- 
receptive  devices,  or  both,  have  all  their  positive 
poles  connected  to  a  single  positive  lead  or  conduc- 
tor, and  all  their  negative  poles  to  a  single  nega- 
tive lead  or  conductor. 

Circuit,  Open.  A  broken  circuit.  A  circuit,  the  con- 
ducting continuity  of  which  is  broken. 

Circuit,  Parallel.  A  name  sometimes  applied  to  circuits 
connected  in  multiple.  See  Circuit,  Multiple. 

Circuit,  Series.  A  compound  circuit  in  which  the 
separate  sources,  or  the  separate  electro-receptive 
devices,  or  both,  are  so  placed  that  the  current 
produced  in  each,  or  passed  through  each,  passes 
successively  through  the  entire  circuit  from  the 
first  to  the  last. 


Cir-Col 


THE  SIGNAL  DICTIONARY 


Circuit,  Short.  A  shunt  or  by-path  of  comparatively 
small  resistance  around  the  poles  of  an  electric 
source,  or  around  any  portion  of  a  circuit,  by  which 
so  much  of  the  current  passes  through  the  new 
path,  as  virtually  to  cut  out  the  part  of  the  circuit 
around  which  it  is  placed,  and  so  prevent  it  from 
receiving  an  appreciable  current. 

Circuit,  Shunt.  A  branch  or  additional  circuit  provided 
at  any  part  of  a  circuit,  through  which  the  current 
branches  or  divides,  part  flowing  through  the 
original  circuit,  and  part  through  the  new  branch. 

Circular  Mil.  A  unit  of  area  employed  in  measuring 
the  cross-sectional  area  of  wires,  equal  to  .7854  sq. 
mil.  The  area  of  a  circle,  i  mil.,  or  .001  in.  in 
diameter.  One  circular  mil.  equals  .000000785  sq. 
in.  The  area  of  cross-section  of  a  wire  in  circular 
mils,  is  equal  to  the  square  of  its  diameter  in  mils. 

Clear  (verb).  To  put  a  signal  in  the  position  or  aspect 
to  indicate  that  a  train  may  proceed. 

Clear  Signal.  A  common  term  to  denote  the  indica- 
tion of  a  signal  in  the  "proceed"  position.  It  may 
refer  to  a  home  signal  indicating  proceed  at  unlim- 
ited speed;  or  to  such  a  signal  indicating  proceed  at 
limited  speed  (over  a  diverging  track);  or  to  a 
distant  signal  indicating  proceed,  expecting  to  find 
the  next  signal  clear.  In  Great  Britain  "all-clear" 
is  used  in  the  same  sense. 

Clearance  Card.  In  block  signaling  a  written  order 
issued  by  a  signalman  to  authorize  a  train  to  enter 
a  block  when  the  signal  cannot  be  cleared.  Form 
C  of  the  Standard  Code  of  the  American  Railway 
Association  is  shown,  reduced  in  size,  below: 


.COMPANY. 


PILE  A  "R  A  TTOB3   O-AJEWD. 


BLOCK  STATION ,  1»#  ,    H. 

To  ESQINEMAV 

Train  No on track.     Signal  cannot  be  cleared;  proceed. 


,  Signalman. 

This  card  must  be  used  only  in  case  of  failure  of  block  signal  apparatus,  and  when 
block  has  been  duly  reported  clear  by  the  signalman  at  the  block  station  in  advance.  The 
engineman  receiving  it  duly  dated,  timed,  and  signed,  may  proceed. 


[PRINT  NAME.) 


.Superintendent. 


Clearance  Point.  At  a  convergence  of  two  tracks  that 
point  beyond  which  the  widest  cars  or  engines, 
proceeding  in  the  converging  direction,  cannot  run 
without  a  possibility  of  fouling  vehicles  on  the 
other  track. 

Clockwise  Motion.  A  rotary  motion  whose  direction 
is  the  same  as  that  of  the  hands  of  a  clock,  viewed 
from  the  face. 

Clockwork  Signal.  One  of  the  early  forms  of  auto- 
matic block  signal  mechanism;  still  in  use  to  * 
limited  extent  in  New  England.  It  is  a  disk  signal 
revolving  on  a  vertical  spindle.  When  the  disk  or 
target  is  visible  to  the  engineman  it  indicates  stop, 
and  when  turned  with  the  edge  toward  an  ap- 
proaching train  (disk  not  visible)  it  indicates  clear. 
A  common  form  has  a  second  target  of  different 
shape  mounted  on  the  spindle  at  right  angles  to 
the  stop  target  which  serves  for  the  clear  indica- 
tion. The  Stop  target  is  usually  painted  red,  and 
the  proceed  target,  when  used,  is  painted  white  or 
green.  See  Night  Signal  Indication.  The  spindle 


is  rotated  through  a  chain  of  gears  similar  to  the 
works  of  a  clock,  by  a  weight  suspended  inside 
of  the  iron  signal  post.  A  detent  operated  by  a 
magnet  controlled  by  the  track  circuits  prevents 
the  disk  from  revolving  more  than  one-quarter  of 
a  revolution  for  each  operation  of  the  signal. 

Closed  Circuit.  An  electric  circuit  which  is  complete. 
The  term  is  familiarly  used  to  denote  a  circuit 
which  is  normally  complete.  In  railway  signaling 
the  normal  condition  of  the  apparatus  is  that  which 
exists  when  no  train  is  on  the  line.  For  example, 
in  automatic  block  signaling  of  the  simplest  form 
the  signal  stands  normally  at  "clear"  or  "proceed." 
in  readiness  for  the  next  train.  It  is  held  in  that 
position  through  the  instrumentality  of  an  electro- 
magnet, energized  by  a  battery.  To  change  the 
signal  from  this  to  the  stop  position,  the  current 
from  the  battery  is  cut  off  by  opening  the  circuit 
at  the  track  relay,  thus  de-energizing  the  signal 
magnet.  With  the  apparatus  arranged  in  this  way 
the  breaking  of  the  circuit  at  any  point,  as  by  the 
unobserved  corrosion  of  a  wire  or  the  failure  of 
the  current  by  the  exhaustion  of  the  battery,  will 
result  in  setting  the  signal  at  stop,  thus  leading 
to  the  stopping  of  any  train  that  may  come  along 
the  line,  and  thereby  calling  attention  to  the  fault. 
This  is  the  only  safe  arrangement.  If  the  circuit 
were  arranged  normally  open  (that  is,  normally 
broken  at  some  point)  so  that  it  would  require  to 
be  closed  to  set  the  signal  in  the  stop  position, 
any  such  failure  of  wire  or  battery  would  introduce 
a  condition  of  danger,  as  the  signal  might  stand 
at  "clear"  (because  of  the  failure  of  the  electric 
apparatus  to  move  it  to  the  stop  position)  when 
it  ought  to  indicate  "stop."  See  Open  Circuit. 

Closed-circuit  Voltmeter.  A  voltmeter  intended  to  be 
in  permanent  connection  with  the  pressure  it  is 
designed  to  measure. 

Closed  Switch.  A  switch  (in  a  railway  track)  which 
is  set  for  the  normal  current  of  traffic;  an  outlying 
or  siding  switch,  set  for  the  main  track. 

Coil,  Induction.  An  apparatus  consisting  of  two  paral- 
lel coils  of  insulated  wire  employed  for  the  produc- 
tion of  currents  by  mutual  induction.  A  rapidly 
interrupted  battery  current,  sent  through  a  coil 
of  wire  called  the  primary  coil,  induces  alternating 
currents  in  a  coil  of  wire  called  the  secondary  coil. 
As  heretofore  made,  the  primary  coil  consists  of  a 
few  turns  of  a  thick  wire,  and  the,  secondary  coil  of 
many  turns,  often  thousands,  of  fine  wire.  Such 
coils  are  generally  called  Ruhmkorff  coils,  from  thr 
name  of  a  celebrated  manufacturer  of  them. 

Colors  of  Signals.  A  semaphore  arm  gives  its  indica- 
tion by  form  and  position,  independent  of  its  color, 
but  for  convenience  the  blades  are  usually  painted 
red  for  home  signals  and  yellow  or  green  for  the 
distant  signals.  A  white  transverse  stripe  is  com- 
mon (see  Figs.  225-228).  On  a  few  roads  all  signal 
arms  are  painted  one  color  (yellow).  The  back 
sides  of  blades  are  painted  white  or  a  neutral  color. 
In  enclosed  disk  signals  the  disk  is  red  for  home 
(stop)  signal,  and  for  the  distant  it  is  green  or  yel- 
low, according  to  the  colors  used  in  the  light  at 
night.  The  efficiency  of  an  enclosed  disk  signal 
depends  on  the  contrast  between  the  appearance 
of  the  disk  and  that  of  the  surrounding  surface 
of  the  case.  When  the  signal  is  cleared  (the  disk 
withdrawn  from  sight)  the  inner  surface  of  the 


IO 


THE   SIGNAL   DICTIONARY 


Col-Con 


back  of  the  case  (white)  constitutes  the  clear  signal. 
See  Night  Signal  Colors. 

Coleman  Lock  and  Block  Instrument.  An  improved 
form  of  the  Sykes  lock  and  block  instrument  for  a 
controlled  manual  block  system,  devised  by  J.  P. 
Coleman.  See  pages  27-45. 

Common  Wire.  A  wire  used  jointly  or  "in  common" 
by  two  or  more  electric  circuits,  through  part  of 
the  route  of  each.  When  two  or  more  circuits  are 
supplied  with  current  from  one  source,  as  a  battery, 
the  main  leads  from  the  battery,  are  "common"  to 
all  such  circuits; 

In  early  signal  practice  it  was  customary  to 
economize  in  the  use  of  wire  by  making  the  ground 
a  "common"  return  conductor  for  nearly  all  cir- 
cuits in  the  same  manner  as  is  still  done  in  the 
telegraph.  But  on  account  of  difficulty  in  maintain- 
ing good  ground  connections  this  practice  has  been 
discontinued  to  a  large  extent,  the  "common"  re- 
turn wire  being  substituted. 

NOTE. — This  practice,  although  at  present  in  gen- 
eral use,  has  certain  undesirable  features.  Its  use 
results  in  complications  in  circuits,  and  occasionally 
trouble  is  caused  by  the  common  wire  being  over- 
loaded, resulting  in  a  drop  in  potential  between 
different  points.  Again,  if  the  common  wire,  as, 
for  instance,  at  a  power  interlocking  plant,  be- 
comes disconnected  or  broken  it  is  likely  to  inter- 
fere with  the  operation  of  the  entire  plant,  and  also 
under  certain  conditions  is  liable  to  cause  func- 
tions to  operate  improperly.  Foreign  currents  also 
are  sometimes  collected  or  distributed  by  the  com- 
mon wire,  especially  where  it  extends  several  miles, 
as  in  automatic  block  signaling,  and  to  limit  the 
effects  of  such  disturbing  elements  it  is  the  prac- 
tice on  some  roads  to  limit  the  length  of  common 
wires  to  a  few  miles. 

Commutator.  Any  device  for  changing  in  one  portion 
of  a  circuit  the  directions  of  electromotive  forces 
or  currents  in  another  portion.  A  device  for  chang- 
ing alternating  into  continuous  currents,  or  vice 
versa. 

Compensator.  A  device  for  increasing  and  decreasing 
the  length  of  long  lines  of  pipe  or  wire  to  adjust 
them  to  changes  in  the  temperature  of  the  atmos- 
phere, so  as  to  keep  the  length  of  the  pipe  or  wire 
constant.  In  pipe  lines  this  is  accomplished,  where 
the  direction  of  the  line  is  changed,  by  different 
arrangements  of  cranks,  and  in  straight  lines  by  a 
"Lazy  Jack."  For  wire  lines  various  automatic 
compensators  have  been  tried  and  have  been  re- 
jected as  unsatisfactory.  See  Pipe  Compensator; 
Wire  Compensator.  See  Figs.  1162-1175,  1409- 
1410. 

Condensance.     Capacity  reactance. 

Condenser.  A  device  for  increasing  the  capacity  of  an 
insulated  conductor  by  bringing  it  near  another 
earth-connected  conductor  but  separated  therefrom 
by  any  medium  that  will  permit  electrostatic  induc- 
tion to  take  place  through  its  mass.  Any  variety 
of  electrostatic  accumulator. 

Conductance.  A  word  sometimes  used  in  place  of 
conducting  power.  The  reciprocal  of  resistance. 
In  a  continuous-current  circuit  the  ratio  of  the 
current  strength  to  the  E.M.F.  In  an  alternating- 
current  circuit  the  quantity  whose  square  added 
to  the  square  of  the  susceptance  is  equal  to  the 
square  of  the  admittance. 


Conduction,  Electric.  The  so-called  flow  or  passage 
of  electricity  through  a  metallic  or  other  similar 
substance.  The  ability  of  a  substance  to  determine 
the  direction  in  which  electric  energy  shall  be 
transmitted  through  the  ether  surrounding  it.  The 
ability  of  a  substance  to  determine  the  direction  in 
which  a  current  of  electricity  shall  pass  from  one 
point  to  another. 

Conductivity.  The  capacity  of  a  substance,  as  a  wire, 
for  conveying  electric  current;  the  reciprocal  of 
electric  Resistance,  which  see. 

Conductor.  Any  substance  which  will  permit  the  so- 
called  passage  of  an  electric  current.  A  sub- 
stance which  possesses  the  ability  of  determining 
the  direction  in  which  electric  energy  shall  pass 
through  the  ether  in  the  dielectric  surrounding  it. 

Conduit.  A  tube  of  wood,  clay,  iron  or  fiber,  enclosing 
electric  wires,  usually  under  ground.  See  Figs. 
3822-3850. 

Constant-potential  Circuit.  A  circuit  whose  potential 
is  maintained  approximately  constant.  A  multiple- 
arc  or  parallel-connected  circuit. 

Contact  Finger.     See  Front  Contact  and  Back  Contact. 

Contact  Rail.  In  automatic  train-stopping  or  cab-sig- 
naling systems,  a  bar  of  metal,  similar  to  or  per- 
haps consisting  of  a  piece  of  track  rail,  which  is 
fixed  on  the  ties,  alongside  of  one  of  the  rails 
of  the  track,  or  perhaps  midway  between  the  two 
rails,  in  such  a  way  as  to  be  rubbed  by  an  electrical 
conductor  fixed  on  the  engine  or  the  other  vehicle. 
With  suitable  insulation  and  insulated  connections 
the  contact  of  the  moving  with  the  fixed  part  is 
made  to  complete  an  electric  circuit  as  the  train 
passes.  Cab-signal  systems  have  been  proposed 
in  which  there  would  be  a  continuous  contact  rail 
throughout  the  length  of  the  railway. 

Continuous  Current.  An  electric  current  which  flows 
in  one  and  the  same  direction.  A  steady  or  non- 
pulsating  direct,  current. 

Controlled  Manual  Block  System.  The  manual  block 
system  safeguarded  by  the  addition  of  electric 
locks,  attached  to  the  signal  levers  and  controlled 
from  the  adjoining  block  stations,  so  arranged  that 
a  clear  signal  cannot  be  displayed  to  admit  a  train 
into  a  block  without  the  simultaneous  action  and 
consent  of  the  signalmen  at  both  ends  of  the  block. 
The  controlled  manual  system  was  developed  in 
England  by  W.  R.  Sykes,  where  it  is  known  as 
"Lock  and  Block."  In  1882  a  few  Sykes  instru- 
ments were  installed  on  the  New  York  Central  in 
and  near  New  York  City.  Coleman's  controlled 
manual  instrument  is  an  improved  form  of  the 
Sykes  instrument,  devised  by  J.  P.  Coleman,  and 
the  few  original  Sykes  instruments  installed  in 
the  United  States  have  been  replaced  by  it.  Track 
circuit  control  (at  each  station)  is  an  important 
element  of  the  system,  but  in  some  cases  it  is  not 
used.  By  the  addition  of  a  complete  track  cir- 
cuit throughout  the  length  of  the  block  sections 
the  controlled  manual  system  can  be  made  to  more 
surely  provide  against  a  collision  due  to  the  acci- 
dental breaking  of  a  train.  If,  by  accident  or 
otherwise,  the  rear  car  of  a  train  should  be  detached 
and  left  in  a  section,  while  the  rest  of  the  train 
passed  out  of  it,  and  if  in  such  a  case  the  signalman 
at  the  outgoing  end  should  carelessly  assume  that 
the  whole  of  the  train  had  passed  him,  it  would 
be  possible  for  him  to  empower  the  station  at  the 


Con-Dan 


THE   SIGNAL  DICTIONARY 


ir 


entering  end  to  send  forward  a  second  train.  The 
continuous  track  circuit  prevents  this,  as  in  auto- 
matic block  signaling.  See  Electric  Train  Staff. 
See  pages  27-45. 

Converter.  A  dynamo-electric  machine  having  one 
armature  and  one  field  for  converting  alternating 
current  to  direct  current,  or  direct  current  to  alter- 
nating current.  The  term  to  be  preceded  by  the 
words  "alternating  current-direct  current"  (A.C.- 
D.C.)  orv'direcl  current"  (D.C.). 

Convertible  Lantern.  A  lantern  equipped  for  the  use 
of  either  oil  or  electric  lamps. 

Copper-clad  Wire.  An  electrical  conductor  made  with 
a  steel  center,  surrounded  by  copper.  For  lines 
strung  on  poles,  by  the  use  of  copper  and  steel  in 
the  right  proportions,  copper  for  conductivity  and 
steel  for  mechanical  strength,  wire  of  a  given  con- 
ductivity can  be  made  at  a  cost  less  than  that  for 
either  copper  wire  or  steel  wire.  The  welding  of 
the  steel  and  the  copper  is  done  by  the  "Monnot" 
process. 

Core,  Lamination  of.  Structural  subdivisions  of  the 
cores  of  magnets,  armatures  and  pole-pieces  01 
dynamo-electric  machines,  electric  motors,  or 
similar  apparatus,  in  order  to  prevent  heating  and 
subsequent  loss,  of  energy  from  the  production 
of  local,  eddy  or  Foucault  currents. 

These  laminations  are. obtained  by  forming  the 
cores  of  sheets,  rods,  plates,  or  wires  of  iron  insu- 
lated from  one  another. 

Coulomb.  The  practical  unit  of  electric  quantity.  Such 
a  quantity  of  electricity  as  would  pass  in  one  second 
through  a  circuit  conveying  one  ampere. 

Counter-electromotive  Force.  An  opposed  or  reverse 
electromotive  force  which  tends  to  set  up  a  current 
in  the  opposite  direction  to  that  actually  produced 
by  a  source.  In  an  electric  motor,  an  electromotive 
force  produced  by  the  rotation  of  the  armature  and 
opposed  to  that  produced  by  the  driving  current. 

Counterweight.  In  a  semaphore,  a  weight  so  con- 
nected that,  in  case  of  breakage  of  the  wire  or  the 
pipe  controlling  the  signal,  the  weight  will  fall  and 
pull  the  signal  to  the  horizontal  (stop)  position. 
Any  failure  of  a  signal  should  result  in  an  indica- 
tion adverse  to  the  movement  of  trains,  thus  tend- 
ing to  safety  and  to  the  discovery  and  repair  of  the 
defect  which  has  caused  the  failure.  Semaphores, 
in  which  the  arm  is  inclined  upward  for  the  pro- 
ceed indication,  need  no  counterweight.  See  Figs. 
i 409- 14 i o^  1639-1646,  i 700. 

Crane.     See  Staff  Crane. 

Crank.  In  interlocking  work,  a  lever  used  to  change 
the  alinement  or  direction  of  travel  of  a  pipe. 
Cranks  are  straight  when  the  arms  make  an  angle 
of  180  deg.  with  each  other.  See  Equalizer  and 
Straight  Arm  Compensator.  "T"  cranks  have  three 
arms  and  are  shaped  like  the  letter  T.  When 
the  arms  are  at  90  deg.  to  each  other  the  term 
"crank"  is  used  alone.  See  Figs.  1134-1145,  1154- 
1160,  1177-1178. 

Crank  Stand.  The  frame  in  which  cranks  (in  a  pipe 
line)  arc  supported.  See  Crank. 

Cross  (of  wires).  The  accidental  contact  of  electrical 
conducting  wires.  In  signaling,  such  an  accident, 
by  increasing  the  current  in  a  wire  or  reversing  its 
polarity,  or  by  energizing  a  wire  which  should  be 
dead,  may  produce  derangements  of  apparatus. 
Circuits  controlling  signals  should  always  be  so 


arranged  that  either  a  cross  6r  a  break  will  cause 
the  signal  to  indicate  stop,  or  if  already  thus  indi- 
cating to  remain  so  until  the  fault  is  corrected. 

Cross  Arm.  An  arm,  usually  of  wood,  fastened  to  a 
telegraph  pole,  near  the  top,  at  right  angles  to  the 
pole;  designed  to  carry  the  pins  and  insulators  to 
which  line  wires  are  attached.  See  Figs.  3002-3043. 

Cross  Locking.  In  Saxby  &  Farmer  interlocking,  the 
transverse  bar  which  is  moved  by  the  locking  dog. 
See  26,  Fig.  794. 

Crossing  Bar.  A  detector  bar  used  near  a  crossing  and 
operated  by  a  separate  lever  in  an  interlocking  ma- 
chine. By  its  use  a  train  on  the  crossing  is  pro- 
tected against  the  wrongful  clearing  of  signals  for 
trains  on  conflicting  routes.  See  Fouling  Ear.  See 
Figs.  750-753- 

Crossover.  A  short  track  leading  from  one  to  the 
other  of  two  parallel  tracks.  See  Figs.  439-441, 
756,  760-763,  7/0-771,  780-785,  1176,  1563-1567. 

Crowfoot  Zinc.  A  form  of  zinc  plate  used  in  a  Gravity 
Cell,  with  a  vertical  stem  and  several  radiating 
spokes  or  toes,  resembling  the  foot  of  a  bird.  See 
.Fig.  2320. 

Current,  Electric.     See  Electric  Current. 

Current  of  Traffic.  On  a  double-track  railway  the 
normal  movement  of  trains  in  a  given  direction,  as 
for  example,  eastward  on  the  south  track,  and  west- 
ward on  the  north.  To  move  westward  on  the 
south  track  or  eastward  on  the  north  track,  in  that 
case,  is  "against  the  current  of  traffic." 

Current  Strength.  In  a  direct  current  circuit  the 
quotient  of  -the  total  electromotive  force  divided 
by  the  total  resistance.  The  time-rate-of-flow  in 
a  circuit  expressed  in  amperes,  or  coulombs  per 
second.  In  an  alternating  current  the  quotient  of 
the  total  electromotive  force  divided  by  the  im- 
pedance. See  Alternating  Current. 

Cutout.  In  an  electric  circuit  a  switch  for  changing 
or  stopping  the  flow  of  current,  so  that  a  piece  of 
apparatus,  as,  for  example,  an  electromagnet,  which 
has  formed  a  part  of  the  circuit  is  left  de-energized 
— cut  out  of  the  circuit.  A  safety  fuse. 

Cut  Section.  In  automatic  block  signaling,  a  familiar 
term  used  in  cases  where  a  block  section  is  too  long 
to  maintain  a  single  track  circuit  (by  reason  of  the 
tendency  for  leakage  through  ties  and  roadbed  to 
reduce  the  difference  in  potential  between  the  run- 
ning rails).  The  block  section  •  is  divided  at  the 
middle — or  in  extreme  cases  is  divided  into  three 
parts — and  is  called  a  "cut  section."  A  section 
which  does  not  reach  to  the  signal  may  repeat  into 
the  adjacent  section  by  a  relay,  or  it  may  be  made 
to  control  the  home  signal  directly  by  a  line  wire. 
See  Figs.  406-483,  485,  487,  493-494,  498,  501,  505. 

Cycle.  In  an  alternating  current  a  complete  change  in 
direction  from  any  given  value  through  zero  to 
an  equal  value  in  the  opposite  direction  and  back. 
The  frequency  is  expressed  as  the  number  of  cycles 
per  second. 

D 

D.  C.     Abbreviation  for  Direct  Current. 

Danger.  A  term  formerly  used  to  denote  the  "stop" 
indication  of  a  signal;  still  used  in  the  combined 
term  "normal  danger,"  meaning  an  automatic  block 
signal  system,  in  which  the  signals  indicate  stop 


12 


THE   SIGNAL  DICTIONARY 


Dar-Dia 


(or,  in  the  case  of  a  distant  signal,  caution)  at  all 
times  except  when  a  train  is  approaching. 
d'Arsonval  Galvanometer.  The  class  of  galvanometers 
in  which  the  needle  or  mirror  is  attached  to  and 
actuated  by  a  small  coil  which  is  suspended  by 
means  of  a  fine  wire  between  the  poles  of  a  per- 
manent magnet.  The  axis  of  the  coil  is  normally 
at  right  angles  with  the  lines  of  the  field.  Current 
is  lead  into  the  coil  by  means  of  the  small  suspen- 
sion wire  and  Leaves  the  coil  by  a  flexible  wire 
usually  in  the  form  of  a  helical  spring  attached  un- 
derneath the  coil. 

Dash  Pot.  A  cylinder  with  a  piston,  designed  *to  act 
as  an  air  cushion  for  a  falling  weight,  the  piston 
being  attached  to  a  rod  supporting  the  weight.  See 
6,  Figs.  523-526;  8,  Fig.  537;  4,  Fig.  580. 

Dead-beat  Galvanometer.  An  aperiodic  galvanometer, 
or  one  whose  needle  comes  quickly  to  rest  instead 
of  repeatedly  swinging  to-and-fro.  A  heavily 
damped  galvanometer. 

Deflecting  Bar.  A  device  for  changing  the  direction  of 
a  line  of  pipe.  See  Figs.  1179-1204. 

Deflecting  Bar  Leadout.     See  Figs.  1007-1009. 

Deflecting  Stand.    See  Figs.  1179-1204. 

Derail  (noun).  Any  device  in  a  fixed  location,  for 
throwing  cars  and  engines  off  the  track.  A  short 
name  for  Derailing  Switch,  which  see.  See  Figs. 
740,  744,  750,  754,  756,  760,  762,  770,  784,  786,  787, 
1621-1625;  and  Hayes  Derails,  Figs.  1626-1638, 
pages  196-197. 

Derailing  Switch.  A  switch  designed  to  turn  a  train  off 
the  track  for  the  purpose  of  preventing  it  from  run- 
ning into  danger;  used  in  connection  with  stop 
signals  on  lines  approaching  grade  crossings  of 
other  railways,  or  drawbridges,  or  any  particularly 
dangerous  place.  It  may  be  interlocked  with  a  stop 
signal  so  that  when  the  derail  is  "open,"  to  derail, 
the  signal  must  indicate  stop;  and  before  the  signal 
can  be  cleared  the  derailing  switch  must  be  set  so 
as  not  to  derail  an  approaching  train.  See  Figs. 
740-787.  A  diverging  track,  if  not  too  sharply 
curved,  serves  the  same  purpose  without  causing 
derailment.  Derailing  switches  worked  by  hand 
(sometimes  not  interlocked  with  the  switch)  are 
used  near  the  ends  of  outlying  side  tracks,  espe- 
cially where  a  movement  from  the  siding  to  the  main 
line  has  the  benefit  of  a  descending  grade.  Such  a 
derailing  switch  is  regularly  left  open,  so  as  to  de- 
rail any  cars  which  may  by  accident  run  from  the 
siding  toward  the  main  line  when  no  attendant  is 
near. 

Detector  Bar.  A  device  for  preventing  the  movement 
of  switches  under  trains.  A  long,  thin  strip  of 
metal  is  mounted  on  pivoted  links  alongside  of  the 
track  rail,  on  its  outer  side,  in  such  a  way  that 
when  moved  longitudinally  the  bar  is  lifted  higher 
than  the  top  of  the  rail.  The  bar  is  so  connected 
to  the  switch  movement,  with  which  it  is  used,  that 
it  must  be  lifted  before  the  switch  is  moved.  It  is 
located  either  in  advance  or  in  rear  of  the  switch, 
and  sometimes  both.  If  any  pair  of  wheels  is  on 
the  rail  along  which  it  is  mounted  the  bar  is  pre- 
vented from  moving  by  coming  in  contact  with  the 
wheel  tread  which  projects  over  the  edge  of  the 
rail.  If  the  detector  bar  cannot  move,  the  switch 
cannot  be  moved,  and  the  arrangement  therefore 
prevents  throwing  a  switch  under  a  car.  Detector 
bars  are  used  with  both  mechanical  and  power- 


operated  switches.  They  derive  the  name  "detector 
bar"  from  the  fact  that  the  signalman  in  a  mechan- 
ical interlocking  can  detect  by  the  pull  on  the  lever, 
whether  the  detector  bar  is  blocked.  In  power  in- 
terlocking they  are  now  being  replaced  in  many 
installations  with  electric  track  circuits  controlling 
electric  locks  on  the  switch  levers.  See  Detector 
Bar,  Inside;  also  Electric  Detection;  Detector 
Track  Circuit,  Detector  Locking.  See  Figs.  1479- 
1485,  1543-1617. 

Detector  Bar  (inside).  An  arrangement  for  preventing 
the  movement  of  a  switch  while  it  is  occupied  by  a 
car.  The  common  Detector  Bar,  which  see,  keeps 
the  switch  locked  by  the  pressure  of  the  outer  part 
of  the  treads  of  the  wheels  of  the  car.  The  inside 
bar  is  controlled  by  the  flanges  of  the  wheels.  The 
older  form  of  inside  bar  was  arranged  normally  to 
lie  flat,  and  in  moving  was  turned  upward  by  the 
movement  of  a  long  rod  lying  parallel  to  the  bar 
and  fixed  to  it,  the  rod  being  turned  on  its  axis.  A 
later  form  is  worked  in  about  the  same  way  as  the 
outside  bar.  The  effectiveness  of  the  outside  bar 
depends  on  having  car  wheels  with  treads  wide 
enough  always  to  extend  a  good  distance  outside  of 
the  head  of  the  rail.  With  wide-headed  rails  this 
is  an  uncertain  factor. 

Inside  detector  bars  are  objectionable  because, 
by  reason  of  the  presence  of  switch  rods  and  other 
track  accessories,  it  is  impossible  in  many  situa- 
tions to  put  the  bars  where  they  are  needed,  and 
also  because  wheel  flanges  are  not  of  uniform 
depth.  For  this  and  other  reasons  the  outside  bar 
is  more  generally  used.  But  the  introduction  of 
rails  with  very  wide  heads  has  lessened  the  effec- 
tiveness of  outside  bars;  because  with  the  width  of 
the  wheel  treads  only  a  little  greater  than  the 
width  of  the  rail  head  the  bar  may  not  be  properly 
held  down.  This  has  led  to  the  introduction  of 
"electric  detection"  for  this  purpose,  and  also 
"switch  guards,"  designed  to  approach  the  wheel 
from  the  side  instead  of  from  below,  as  in  Figs. 
1604-1607,  and  1608-1611. 

Detector  Bar  Driving  Piece.  A  stud  and  plate,  or  eye, 
bolted  to  a  detector  bar,  on  which  is  attached  the 
driving  rod  connected  with  the  switch  movement 
with  which  the  detector  bar  is  used.  See  Figs. 
1557-1559. 

Detector  Bar  Link.  A  short  link  supporting  a  detector 
bar,  and  so  pivoted  on  a  clip  fastened  to  the  rail 
that  the  detector  bar  in  moving  longitudinally  must 
also  move  upward  and  above  the  top  of  the  rail. 
See  Figs.  1543-1544,  1568-1603. 

Detector  Bar  Stop.  A  lug  bolted  to  the  rail  on  which 
the  detector  bar  rests  when  the  stroke  is  completed. 
See  Figs.  1545-1561. 

Detector  Locking.    See  Electric  Detection. 

Detector  Track  Circuit.  A  track  circuit  used  in  con- 
nection with  electric  detection,  which  see.  So  called 
because  used  to  perform  the  same  function  as  a 
detector  bar. 

Diagram,  Track.     See  Track  Indicator,  Track  Model. 

Diaphragm  Valve.  A  valve,  controlling  the  admission 
of  compressed  air  from  an  operating  pipe  to  a 
switch  or  signal  cylinder,  which  is  itself  worked  by 
compressed  air  in  another  pipe — the  control  pipe. 
The  pressure  in  the  control  pipe,  increased  or  di- 
minished by  the  signalman  in  the  cabin,  moves  a 
flexible  leather  diaphragm  up  or  down  and  thereby- 


Die-Dwa 


THE   SIGNAL  DICTIONARY 


actuates  the  valve  stem.     See  Pneumatic  Interlock- 
ing, Figs.  2029,  2031,  2033. 

Dielectric.  Any  substance  which  permits  electrostatic 
induction  to  take  place  through  its  mass. 

The  substance  which  separates  the  opposite  coat- 
ings of  a  condenser  is  called  the  dielectric.  All 
dielectrics  are  non-conductors. 

All  non-conductors  or  insulators  are  dielectrics, 
but  their  dielectric  power  is  not  exactly  propor- 
tional to  their  non-conducting  power. 

Substances  differ  greatly  in  the  degree  or  ex- 
tent to  which  they  permit  induction  to  take  place 
through  or  across  them.  Thus,  a  certain  amount 
of  inductive  action  takes  place  between  the  in- 
sulated metal  plates  of  a  condenser  across  the  layer 
or  air  between  them. 

A  dielectric  may  be  regarded  as  pervious  to 
rapidly  reversed  periodic  currents,  but  opaque  to 
continuous  currents.  There  is,  however,  some  con- 
duction of  continuous  currents. 

Differential  Relay.  A  relay,  the  coils  of  which  have 
two  or  more  different  windings;  or  a  relay  having 
two  or  more  magnets  acting  in  certain  relation  to 
each  other.  See  Figs.  500,  502,  504,  505. 

Direct  Current.  A  current  of  electricity  constant  in 
direction  as  distinguished  from  an  Alternating  Cur- 
rent, which  see.  A  continuous  current.  The  cur- 
rent derived  from  all  primary  and  storage  batteries 
is  direct  current. 

Direct  Current  Converter.  Converts  from  a  direct  cur- 
rent to  a  direct  current  of  different  voltage. 

Disengaging  Lever.  A  lever  hung  by  shackles  from 
the  balance  lever  of  a  signal  when  the  signal  is  wire 
connected.  The  pulling  and  back  wires,  which  see, 
are  hooked  to  the  disengaging  lever  in  such  a 
manner  that  should  the  back  wire  break  the  disen- 
gaging lever  would  be  released  and  fall  to  the 
ground,  thereby  disconnecting  the  signal  from  its 
operating  mechanism  and  allowing  it  to  go  to  the 
stop  position.  See  Figs.  1409-1410. 

Disk  Signal.  A  signal  in  which  the  day  indications  are 
given  by  the  color  or  position  of  a  circular  disk. 
The  term  is  commonly  restricted  to  an  Enclosed 
Disk.  Signal,  which  see.  A  Clockwork  Signal,  which 
see,  is  a  disk  signal  in  which  the  day  indications 
are  given  by  the  position  of  the  disk  as  it  is  turned 
to  one  or  another  of  two  positions  by  the  revolution 
on  its  axis  of  a  vertical  spindle.  See  Figs.  512-520. 

Distant  Signal.  A  fixed  signal  situated  1,500  ft.  to  3,000 
ft.  or  more  in  the  rear  of  a  home  signal  to  indicate 
to  an  engineman  whether  or  not  he  may  expect  to 
find  the  home  signal  in  the  clear  position.  It  is 
distinguished  from  home  signals  by  a  notch  in  the 
end  of  the  blade.  Finding  the  distant  signal  in  the 
"clear"  position,  trains  may  proceed  at  unchecked 
speed,  while  if  it  shows  "caution"  it  is  a  warning 
that  the  train  must  be  prepared  to  stop  at  the  home 
signal.  On  a  line  where,  by  reason  of  curves  and 
intervening  buildings,  hills  or  trees,  the  home  sig- 
nal cannot  be  seen  by  the  approaching  engineman 
until  he  is  quite  near  it;  or  on  any  line,  curved  or 
straight,  when  the  engineman's  view  is  obscured 
by  fog  or  by  falling  snow,  distant  signals  are  nec- 
essary in  order  to  avoid  delay  to  fast  trains,  as 
without  this  preliminary  information  the  speed  of 
such  trains  would  have  to  be  materially  slackened 
in  order  to  enable  the  engineman  to  be  sure  of  the 
reading  of  the  home  signal  before  he  passed  it.  A 
mechanical  distant  signal  is  so  interlocked  that  it 


can  never  be  cleared  until  the  home  signal  is 
cleared,  and  if  there  are  other  signals  for  that 
route  at  that  station  on  that  track  the  distant  is  so 
interlocked  that  all  of  them  must  be  cleared  before 
it  can  be  cleared.  A  distant  signal  may  be  fixed 
on  the  same  post  with  the  home  signal  for  the  next 
section  in  the  rear,  and  in  that  case  it  is  arranged 
to  be  controlled  by  the  latter  in  such  a  way  that 
whenever  the  home  goes  to  stop  the  distant  will 
go  to  caution,  even  if  its  own  home  signal  (a  block 
in  advance)  does  not  require  it  to  do  so.  This  is 
done  to  avoid  giving  to  enginemen  what  might 
seem  to  be  two  inconsistent  indications  at  the  same 
point.  In  the  automatic  block  signal  system  the 
distant  signal  is  controlled  by  the  home  signal,  and 
is  usually  mounted  on  the  same  post  with  the  first 
home  signal  in  the  rear.  In  a  system  of  Three- 
Position  Automatic  Block  Signals,  which  see,  each 
signal  gives  a  distant  indication  for  the  next  signal 
in  advance.  The  various  forms  and  indications  of 
distant  signals  are  shown  in  Figs.  226,  231-235,  252, 
253,  257-259,  264,  310-318.  See  Home  Signal. 

Distant  Switch  Signal.  A  signal,  arranged  like  a  me- 
chanical distant  signal,  but  used  only  to  indicate 
the  position  of  an  outlying  switch.  Its  lever  is 
usually  interlocked  with  the  lever  of  the  switch. 
Distant  switch  signals  (for  trains  running  in  the 
"facing"  direction)  were  used  considerably  before 
block  signals  were  common;  but  when  the  block 
system  and  interlocking  are  introduced  the  switch 
signal  usually  is  either  removed  or  is  made  a  part 
of  the  new  system.  See  Figs.  1692-1695. 

Dog  Chart.  A  diagrammatic  representation  of  the 
mechanical  locking  for  an  interlocking  machine; 
used  as  a  working  plan  in  making  up  and  fitting  the 
locking.  See  Figs.  741-1006. 

Dog  Locking.     See  Locking. 

Doll.  A  word,  of  doubtful  origin,  sometimes  used  to 
designate  a  short  signal  post,  as  the  bracket  masts 
of  a  bracket  signal. 

Double  Jaw.     See  46-53,  Figs.  1047-1121. 

Double-Pole  Switch.  A  switch  which  simultaneously 
breaks  the  circuit  of  both  positive  and  negative 
leads. 

Dummy.  Literally,  a  counterfeit;  used  to  designate  a 
bracket  mast  on  a  bracket  signal,  bearing  no  signal 
arm  and  designed  merely  to  aid,  by  its  position 
relative  to  the  other  bracket  masts  in  showing  to 
which  of  two  or  more  tracks  a  signal  applies.  A 
dummy  may  carry  a  light  of  distinctive  color  to 
fulfil  its  function  at  night. 

Duplex  Lock.  A  lock  for  a  switch  with  two  plungers, 
one  of  which  locks  the  switch  in  its  normal  posi- 
tion and  the  other  in  the  reversed  position.  It  is 
so  arranged  that  both  cannot  enter  the  same  hole 
in  the  lock  rod.  See  F,  Figs.  1467-1478. 

Dwarf  Interlocking  Machine.  A  small  interlocking  ma- 
chine often  set  out  of  doors.  In  a  common  form  of 
two-lever  machine  one  lever  works  the  switch  and 
the  other  a  distant  switch  signal.  See  Fig.  1004. 
Except  in  this  case  these  machines  are  used  only 
on  low-speed  tracks,  as  in  freight  yards,  and  the 
locking  is  lever-locking  (not  "preliminary").  See 
Figs.  1703-1705,  3405-3510. 

Dwarf  Semaphore  Signal.  Commonly  abbreviated  to 
"dwarf."  A  low  semaphore  signal  used  for  giving 
indications  for  low-speed  movements,  as  through 
an  interlocking  plant  in  the  reverse  direction  to  th? 


THE- SIGNAL  DICTIONARY 


Dyn-Ele 


normal  current  of  traffic  or  on  or  from  a  side  track- 
Dwarf  semaphore  signals  are  used  also  to  give  in- 
dications in  the  normal  direction,  as  in  the  case  of 
movements  from  a  main  track  to  a  side  track  in 
the  normal  direction,  the  dwarf -being  set  close 
to  the  high  signal  post.  •  Dwarfs  are  frequently 
used  at  terminals  for  movements  in  the  normal 
direction.  See  Figs.  1668-1686.  The  arm  of  a  dwarf 
is  about  three  inches  wide  and  nine  inches  long, 
and  is  usually  about  2  feet  above  the  level  of  the 
rail.  It  is  often  made  of  rubber  or  thin  sheet  metal 
to  prevent  damage  in  case  of  fouling  with  cars  or 
locomotives.  The  day  indications  of  dwarf  arms 
are  the  same  as  for  full-size  semaphore  arms,  as 
shown  in  Figs.  225-276.  For  the  night  indications 
by  color,  see  Night  Signal  Indications.  Figs.  277- 
307,  show  usual  arrangements  of  dwarf  and  high 
signals  with  the  routes  which  they  control. 
Dynamo.  An  electro-mechanical  machine  for  trans- 
forming mechanical  energy  to  electric  energy  and 
vice  versa.  When  used  to  furnish  electric  energy 
it  is  called  a  generator  and  when  used  to  furnish 
mechanical  energy,  a  motor. 

Dynamometer.  A  general  name  given  to  a  variety  of 
apparatus  for  measuring  power. 

E 

E.  M.  F.     Abbreviation  for  Electromotive  Force. 

Eddy  Currents.  Induced  currents  produced  in  the 
armature  core  of  a  dynamo  or  any  small  closed  cir- 
cuit in  the  presence  of  a  changing  magnetic  field. 
See  Induced  Currents.  See  Figs.  680-684. 

Effective  Current  Strength.  The  strength  of  an  alter- 
nating or  sinusoidal  electric  current,  determined  by 
its  heating  effect;  or,  in  other  words,  the  thermally 
effective  current  strength.  That  value  of  the  cur- 
rent strength  of  a  sinusoidal  or  alternating  current 
which  is  equal  to  the  square  root  of  the  mean 
square  of  the  instantaneous  values  of  the  current 
during  one  or  more  cycles.  The  square  root  of  the 
time  average  of  the  square  of  the  current. 

Effective  Reactance.  In  an  alternating  current  circuit, 
the  ratio  of  the  wattless  component  of  an  electro- 
motive force  to  the  total  current.  Apparent  re- 
actance. 

Effective  Resistance.  In  an  alternating  current  circuit, 
the  ratio  between  the  energy  component  of  an  elec- 
tromotive force  and  the  total  current. 

Effective  Value.  That  instantaneous  value  of  alternat- 
ing current  which  is  equal  to  a  direct  current  hav- 
ing the  same  heating  power  as  the  given  alternat- 
ing current.  This  value  is  f or  .707  times  the 

maximum  value.  * 

Efficiency.  The  efficiency  of  an  apparatus  is  the  ratio 
of  its  output  to  its  input.  The  output  and  input 
may  be  in  terms  of  watt-hours,  watts,  volt-amperes, 
amperes,  or  any  other  quantity  of  interest,  thus 
respectively  defining  energy  efficiency,  power  effi- 
ciency, apparent  power  efficiency,  current  efficiency, 
etc.  Unless  otherwise  specified,  however,  the  term 
efficiency  is  ordinarily  assumed  to  refer  to  power 
efficiency. 

When  the  input  and  output  are  expressed  in 
terms  of  the  same  unit,  the  efficiency  is  a  numeri- 
cal ratio,  otherwise  it  is  a  physical  dimensional 
quantity. 

Electric  Bell.     See  Bell,  Electric. 


Electric  Circuit.  A  simple  electric  circuit  consists  of  a 
source  of  electrical  energy,  a  conductor  to  carry 
the  current  to  some  form  of  electrical  device  or 
machine  to  utilize  the  current  and  another  con- 
ductor to  complete  the  circuit  to  the  source  of 
energy.  In  D.  C.  circuits  the  source  may  be  a 
battery,  either  primary  or  storage,  a  dynamo- 
machine  or  a  converter.  In  A.  C.  work  the  source- 
may  be  an  alternator  or  transformer.  The  con- 
ductors for  either  current  may  be  any  of  the  metals 
or  other  substances  having  the  property  of  con- 
ductivity. The  most  common  conductors  in  com- 
mercial use  are  copper  or  iron  wire.  The  earth 
is  a  conductor,  or  more  properly  a  reservoir  of  elec- 
tricity, and  by  providing  good  ground  connections 
may  be  made  to  form  a  portion  of  a  closed  circuit. 
This  is  not  always  feasible  in  signal  work,  however, 
on  account  of  the  difficulty  in  maintaining  good 
ground  connections  and  also  on  account  of  the  in- 
terference caused  by  other  circuits  which  depend  on 
ground  return.  In  signaling  the  devices  to  be  oper- 
ated are  very  numerous.  They  include  relays,  sig- 
nal, switch,  and  derail  operating  mechanisms,  in- 
dicators, annunciators,  locks,  signal  lights,  electric 
bells,  and  staff  and  controlled  manual  signal  ap- 
paratus. 

Circuits  may  be  normally  open  or  normally 
closed,  and  a  number  of  devices  may  be  used  either 
to  open  a  closed  circuit  or  to  close  an  open  circuit. 
Some  such  device  is  ordinarily  included  in  every 
circuit.  In  D.  C.  circuits  the  calculation  of  the  value 
of  the  current  flowing  can  be  made  by  the  appli- 
cation of  Ohm's  Law,  which  see,  or  the  value  can  be 
measured  by  means  of  instruments  included  in  the 
circuit.  In  A.  C.  circuits  it  is  necessary  to  calculate 
the  inductance  and  capacity  of  the  circuit,  then  the 
inductive  and  capacity  reactances  and  obtain  the- 
relation  of  current  to  voltage  by  the  use  of  -both 
these  reactances  and  the  resistance. 

For  divided  circuits  the  current  flowing  in  each, 
branch  is  inversely  proportional  to  its  resistance. 

Electric  Current.  The  quantity  of  electricity  per  sec- 
ond which  passes  through  any  conductor  or  circuit,, 
when  the  flow  is  uniform.  The  rate  at  which  a 
quantity  of  electricity  flows  or  passes  through  a 
circuit.  The  ratio,  expressed  in  terms  of  electric 
quantity  per  second,  existing  between  the  electro- 
motive force  causing  a  current  and  the  resistance 
which  opposes  it. 

The  unit  of  current,  or  the  ampere,  is  equal  to 
one  coulomb  per  second.  (See  Ampere,  and  Cou- 
lomb.) 

The  word  current  must  not  be  confounded  with 
the  mere  act  of  flowing;  electric  current  signifies 
rate  of  flow,  and  always  supposes  an  electromotive 
force  to  produce  the  current,  and  a  resistance  to 
oppose  it. 

The  electric  current  is  assumed  to  flow  out  from 
the  positive  terminal  of  a  source,  through  the  cir- 
cuit and  back  into  the  source  at  the  negative  term- 
inal. It  is  assumed  to  flow  into  the  positive  term- 
inal of  an  electro-receptive  device  such  as  a  lamp, 
motor,  or  storage  battery,  and  out  of  its  negative 
terminal;  or,  in  other  words,  the  positive  pole  of 
the  source  is  always  connected  to  the  positive 
terminal  of  the  electro-receptive  device. 

The  current  that  flows  or  passes  in  any  circuit 
is,  in  the  case  of  a  constant  current,  equal  to  the 


Ele-Ele 


THE   SIGNAL  DICTIONARY 


electromotive   force,   or  difference   of  potential,   di- 
vided by  the  resistance,  as: 

E 
C  =  (See  Ohm's  Law.)     The  flow  of  an  elec- 

R 

trie  current  may  vary  in  any  manner  whatsoever. 
A  current  which  continues  flowing  in  the  same 
direction  no  matter  how  its  strength  may  vary,  is 
called  a  continuous  current,  or  sometimes  a  direct 
current.  If  the  strength  of  such  a  current  is  con- 
stant, it  is  called  an  unvarying  current;  if  its 
strength  is  not  constant,  it  is  a  varying  continuous 
current.  A  regular  varying  continuous  current  is 
called  a  pulsatory  current.  A  current  which  alter- 
nately flows  in  opposite  directions,  no  matter  how 
its  strength  may  vary,  is  called  an  alternating  cur- 
rent. This  may  be  periodic  or  non-periodic. 

Electric  Detection.  The  use  of  track  circuits  and  re- 
lays for  controlling  electric  locks  on  the  switch  or 
signal  levers  of  an  interlocking  machine,  or  open- 
ing the  controlling  circuits  of  switches  to  prevent 
switches  from  being  thrown  under  cars,  a  function 
originally  performed  by  a  Detector  Bar,  which  see. 
Electric  detection,  however,  is  usually  extended  to 
the  fouling  points  of  the  switch  controlled,  and 
may  be  used  instead  of  or  in  addition  to  detector 
bars.  See  Figs.  2055-2088. 

Electric  Interlocking.  Interlocking  apparatus,  in  which 
the  switches  and  signals  are  worked  by  electric 
motors  or  electromagnets.  See  Figs.  1762-1954. 

Electric  Lock.     See  Lock,  Electric. 

Electric  Locking.     See  Locking,  Electric. 

Electric  Motor.     See  Motor,  Electric. 

Electric  Railway.  A  railway  operated  by  electric 
power.  Street  railways  extending  many  miles,  from 
town  to  town,  are  called  interurban.  These  and 
all  electric  lines  operated  by  power  drawn  from  a 
power  house  through  an  overhead  wire  by  a  wheel 
contact  are  called  trolley  roads.  On  many  electric 
lines  in  the  streets  of  large  cities  power  is  taken 
from  a  conductor  laid  in  a  conduit  beneath  the 
surface  of  the  street.  On  many  elevated  and  un- 
derground city  railways  and  on  electrified  lines  of 
some  steam  roads  power  is  taken  from  a  third  rail. 
On  a  few  interurban  lines  and  on  certain  steam 
lines  high-tension  power  is  taken  from  overhead 
conduits  by  sliding  contacts.  On  the  majority  of 
interurban  roads  the  signaling  is  incomplete  or  en- 
tirely lacking,  the  moderate  speeds  and  the  absence 
of  large  terminals  and  junctions  being  held  to  war- 
rant dependance  on  less  costly  methods.  As  speeds 
are  increased  standard  signals  and  signaling  meth- 
ods are  found  necessary. 

Electric  Selector.  An  electromechanical  device  by 
which  the  electric  circuit  of  any  one  of  a  number 
of  audible  or  visible  signals  or  other  devices  may 
be  controlled  from  a  distant  point  without  affect- 
ing any  of  the  other  apparatus  or  devices.  One 
form  of  selector  is  used  for  selective  calling  in 
telephone  or  telegraph  train  dispatching  or  mes- 
sage service;  also  for  the  control  of  signals  from 
a  distant  point.  See  Selective  Signaling,  pages  126- 
132,  Figs.  7I4-739-  Another  form  of  selector,  com- 
monly called  a  switch  box,  is  controlled  by  the 
points  of  a  switch  and  used  to  determine  which 
arm  of  a  signal  or  which  signal  of  a  group  shall  be 
cleared  when  the  switch  is  moved  to  a  given  posi- 
tion. See  Figs.  2416-2486. 

Electric  Slot.  A  device  in  which  the  connection  be- 
tween a  signal  arm  and  its  operating  mechanism  is 


controlled  by  an  electromagnet,  the  connection  be- 
ing broken  when  the  magnet  is  de-energized  and 
established  when  the  parts  are  in  proper  mechan- 
ical relation  and  the  magnet  energized.  Commonly 
used  in  semi-automatic  block  signaling  to  prevent 
the  clearing  of  a  signal,  or  to  cause  it  to  assume 
the  stop  position  when  the  route  or  track  section, 
the  use  of  which  by  trains  is  governed  by  the  sig- 
nal, is  obstructed.  In  telephone  train  dispatching 
it  is  used  to  prevent  the  clearing  of  the  signal  with- 
out the  consent  and  co-operation  of  the  dispatcher. 
See  Figs.  3479-3492. 

Electric  Switch  Lock.  An  electric  lock  controlled  from 
a  signal  cabin  and  attached  to  the  operating  con- 
nection of  an  outlying  switch  to  prevent  the  switch 
from  being  moved  without  the  knowledge  and  con- 
sent of  the  signalman  in  the  cabin.  A  telephone 
or  a  key  and  bell  are  usually  added  in  the  mechan- 
ism case  to  provide  a  means  of  communication  be- 
tween the  switch  and  the  cabin.  With  a  telephone 
attachment  a  condenser  is  sometimes  employed 
and  the  bell  circuit  or  switch  lock  control  circuit 
is  used  for  the  telephone  circuit.  See  Figs.  2813- 
2830. 

Electric  Train  Staff  System.  A  method  of  regulating 
the  movements  of  trains  used  commonly  on  single 
track  lines.  In  the  absolute  staff  system  only  one 
train  at  a  time  is  allowed  in  a  section  between 
block  stations.  This  is  accomplished  by  requiring 
an  engineman  to  have  as  his  authority  for  enter- 
ing a  section  a  staff  or  small  metal  rod,  the  staffs 
being  kept  in  machines  at  the  stations  so  elec- 
trically locked  between  adjacent  stations  that  only 
one  staff  from  the  two  machines  can  be  removed 
at  one  time.  In  the  permissive  staff  system  addi- 
tional trains  may  be  allowed  to  follow  the  first 
one  into  the  section,  the  engineman  of  such  fol- 
lowing trains  having  for  his  authority  to  proceed 
a  section  of  a  divisible  staff  known  as  a  permissive 
staff.  This  staff  must  be  reassembled  and  locked 
in  the  instrument  at  the  outgoing  end  of  the  sec- 
tion before  a  staff  c'an  be  removed  from  that  in- 
strument to  allow  a  train  to  proceed  in  the  op- 
posite direction.  The  pusher  attachment  for  the 
train  staff  system  provides  a  staff  for  the  engine- 
man  on  the  pusher  engine  at  the  same  time  the 
staff  for  the  engineman  on  the  through  engine  is 
released.  The  circuits  are  arranged  to  lock  both 
machines  until  the  pusher  staff  has  been  returned 
to  the  instrument  from  which  it  was  taken,  and  the 
through  engine  staff  locked  in  the  instrument  at 
the  other  end  of  the  section.  The  staff  may  also 
be  designed  to  serve  as  a  key  for  switches  within 
the  section.  See  pages  27-45;  Figs.  346-405. 

Electrical  Bridge  Coupler.     See  Bridge  Circuit  Closer. 

Electrode.  Either  of  the  terminals  of  an  electric 
source.  Either  of  the  terminals  of  an  electric 
source  that  are  placed  in  a  solution  in  which  elec- 
trolysis is  taking  place.  Either  of  the  electro- 
therapeutic  terminals  of  an  electric  source. 

Eiectrogas  Signal.  A  semaphore  signal  worked  by 
compressed  carbonic  acid  gas.  See  Figs.  583-590. 

Electrolysis.  Chemical  decomposition  effected  bv 
means  of  an  electric  current — Houston.  The  op- 
posite of  the  electrochemical  action  which  takes 
place  when  current  is  generated  in  a  A-oltaic  cell. 
The  action  of  the  plates  and  electrolyte  in  charging 
a  storage  battery  is  electrolysis.  The  stable  chem- 
ical elements  and  compounds  of  pure  lead,  lead 
oxide  and  sulphuric  acid  are  dissociated  by  the  pas- 


i6 


THE  SIGNAL  DICTIONARY 


Ele-Fie 


sage  of  the  charging  current  through  the  battery 
and  combine  to  form  unstable  chemical  compounds 
which  do  not  become  active,  however,  until  the 
external  circuit  is  closed.  When  the  battery  is 
discharging,  exactly  the  opposite  chemical  reactions 
take  place,  the  unstable  compounds  rearranging 
themselves  to  form  the  original  stable  compounds 
and  this  chemical  change  is  accompanied  by  the 
generation  of  an  electric  current.  Electrolysis 
manifests  itself  in  the  form  of  corrosion  of  pipes, 
wires,  etc.,  buried  under  ground  or  exposed  in 
damp  places  to  the  effects  of  stray  electric  currents. 
The  moisture  in  the  air  combined  with  carbonic 
acid  or  in  damp  ground  with  earthy  salts  forms  the 
electrolyte,  which  is  necessary  for  the  electrolytic 
action  to  take  place.  The  pitting  or  corrosion  of 
pipes  appears  at  the  point  where  current  leaves 
the  metal  through  the  earth.  It  may  occur  even 
with  currents  of  very  low  voltage. 

Electrolyte.  The  liquid  surrounding  the  plates  or  ele- 
ments of  an  electric  cell,  containing  in  solution 
the  chemicals  which  act  on  the  elements  to  produce 
an  electrochemical  current.  The  electrolyte  is  the 
conductor  of  the  current  within  the  cell  between 
the  plates.  It  is  usually  a  dilute  acid  or  a  solution 
of  acid  derivative  salts  in  water,  or  a  strong  alka- 
line solution. 

Electrolytic  Decomposition.  The  separation  of  a  mole- 
cule into  its  constituent  ions  or  radicals  by  the 
action  of  an  electric  current. 

Electromagnet.  The  magnet  produced  by  the  passage 
of  an  electric  current  through  a  circuit  of  insulated 
wire.  In  common  practice,  electromagnets  consist 
of  a  coil  or  coils  of  insulated  wire,  wound  about  a 
soft  iron  core.  See  Magnet. 

Electromagnetic  Induction.  A  variety  of  electro- 
dynamic  induction  in  which  electric  currents  are 
produced  by  the  motion  either  of  electromagnets, 
or  electromagnetic  solenoids. 

Electromechanical  Slot.     See  Electric  Slot. 

Electromotive  Force.  The  force  which  starts  or  tends 
to  start  electricity  in  motion.  The  maximum  or 
total  generated  difference  of  potential  which  exists 
in  a  circuit. 

Electromotive  Force  of  Induction.  The  electromotive 
force  developed  by  any  inductive  action. 

Electronegative.  In  such  a  state  as  regards  electric- 
ity as  to  be  repelled  by  bodies  negatively  electri- 
fied, and  attracted  by  those  positively  electrified. 
The  ions  or  radicals  which  appear  at  the  anode  or 
positive  electrode  of  a  decomposition  cell. 

Electro-pneumatic  Interlocking.  Interlocking  appa- 
ratus in  which  the  switches  and  signal's  are  worked 
by  compressed  air,  but  the  valves  which  control 
them  are  operated  electrically  from  the  tower.  See 
Figs.  1955-2028. 

Electro-pneumatic  Signals.  Semaphore  signals  worked 
by  compressed  air  and  controlled  by  electric  ap- 
paratus. In  electro-pneumatic  interlocking  the 
electric  control  is  managed  by  the  signalman  in  the 
tower;  in  electro-pneumatic  block  signaling  the  air- 
valves  at  the  signals  are  controlled  by  the  track 
circuit.  See  Figs.  591-602,  685-692. 

Electropositive.  In  such  a  state,  as  regards  an  electric 
charge,  as  to  be  attracted  by  a  body  negatively 
electrified,  and  repelled  by  a  body  positively  elec- 
trified. The  ions  or  radicals  which  appear  at  the 
cathode  or  negative  electrode  of  a  decomposition 
cell. 


Elevator.  In  a  battery  chute,  the  movable  frame  sup- 
porting the  jar  or  jars,  and  its  rope,  arranged  for 
conveniently  raising  the  battery  for  inspection. 
See  Figs.  2364,  2366,  2370-2387,  2396. 

Enclosed  Disk  Signal.  The  simplest  and  earliest  form 
of  automatic  block  signal,  introduced  in  1871,  and 
still  in  use  to  a  small  extent.  The  signal  indica- 
tions are  given  by  color,  both  day  and  night.  A 
circular  disk  of  light  cloth  or  thin  metal,  colored 
red  or  green,  enclosed  in  a  weatherproof  case,  with 
a  glass  front,  is  displayed  for  the  day  indication 
of  stop  or  caution  and  withdrawn  from  sight  fo- 
the  proceed  indication.  See  Figs.  512-520,  3419- 
3420,  3432-3433- 

End  Post.     See  Insulated  Rail  Joint. 

Equalizer.  See  Straight  Arm  Compensator.  See  Figs. 
1174-1175.  1177-1178. 

Escapement  Crank.  A  crank,  used  in  a  "switch  and 
lock  movement,"  by  means  of  which  a  single  stroke 
of  a  lever  performs  three  operations:  First  moves 
the  detector  bar  and  unlocks  the  switch;  second 
moves  the  switch,  third  moves  the  detector  bar 
back  and  locks  the  switch.  See  Figs.  1445-1450. 


F.  P.    Abbreviation  for  Facing  Point. 

F.  P.  L.     Abbreviation  for  Facing  Point  Lock. 

Facing  Point  Lock.  A  lock  for  an  interlocked  switch, 
worked  or  controlled  by  the  signalman,  so  called 
because  used  chiefly  at  facing  point  switches  and 
seldom  or  never  at  trailing  point  switches.  In  and 
near  large  terminals  all  switches  are  provided  with 
locks,  all  being  frequently  traversed  by  trains  in 
both  directions.  The  operating  connection  of  a 
switch  ordinarily  holds  it  in  position;  the  lock  is  an 
additional  provision  for  insuring  accuracy  of  move- 
ment. At  a  trailing  point  switch  extreme  accuracy 
is  not  essential.  See  Figs.  1479-1484. 

Facing  Point  Switch.  A  switch  so  situated,  as  related 
to  an  approaching  train,  that  the  pointed  ends  of 
the  switch  rails  point  toward  the  train.  To  a  train 
coming  from  the  opposite  direction  the  same 
switch  would  be  "trailing."  In  British  practice  the 
word  "points"  (the  two  pointed  switch  rails)  has 
the  same  meaning  as  the  Americaq  term  "switch," 
and  the  English  say  simply  "facing  point."  At  a 
facing  point  switch  a  train  takes  either  one  or  the 
other  of  two  routes.  At  a  trailing  point,  if  the 
switch  is  not  in  the  right  position,  the  wheel  flanges 
will  crowd  the  movable  rails  to  one  side,  and  if  the 
operating  connections  are  rigid  they  will  be  broken. 
At  non-interlocked  switches  such  connections  are 
usually  fitted  with  a  stout  spring,  not  disturbed  by 
ordinary  strains  or  shocks,  which  will  yield  if  the 
rails  are  thus  forced  out  of  position,  and  return 
them  to  their  former  position  as  soon  as  the  wheels 
have  passed.  See  Figs.  1479-1484. 

Feeder.  An  electric  circuit,  used  to  supply  power  to  a 
station  or  service,  as  distinguished  from  circuits 
confined  to  a  single  station  or  used  for  other  pur- 
poses than  supplying  power. 

Field.     A  term  sometimes  used  for  a  magnetic  field. 

Field,  Magnetic.  The  region  of  magnetic  influence 
surrounding  the  poles  of  a  magnet.  A  space  or 
region  traversed  by  lines  of  magnetic  force.  A 
place  where  a  magnetic  needle,  if  free  to  move, 
will  take  up  a  definite  position,  under  the  influence 
of  the  lines  of  magnetic  force. 


Fis-Gra 


THE   SIGNAL  DICTIONARY 


Fish  Wire.  A  wire  used  to  draw  another  through  a 
tube  or  other  opening. 

Fixed  Signal.  A  signal  of  fixed  location  indicating  n 
condition  affecting  the  movement  of  a  train,  as  dis- 
tinguished from  signals  given  by  motion  of  the 
hand  or  by  a  flag  or  a  lamp.  Flags  or  hand  lan- 
terns may  be  temporarily  set  in  fixed  locations.  All 
block  and  interlocking  signals  are  fixed  signals. 

Floor  Push.  An  electric  circuit  closer  fixed  in  the  floor 
where  the  signalman  can  conveniently  close  the  cir- 
cuit by 'pressing  downward  on  a  button  with  his 
foot.  See  Figs.  2498-2503,  2505-2507. 

Flux,  Magnetic.  The  number  of  lines  of  magnetic  force 
that  pass  or  flow  through  a  magnetic  circuit.  The 
total  number  of  lines  of  magnetic  force  in  any 
magnetic  field. 

Fouling  Bar.  A  detector  bar,  which  see,  placed  at  or 
near  a  fouling  point  to  prevent  the  movement  of 
certain  functions  while  a  train  is  on  the  bar.  See 
Crossing  Bar. 

Fouling  Point.  In  the  case  of  converging  tracks,  that 
point  where  a  car  running  toward  the  junction 
would  come  in  contact  with  a  car  or  train  standing 
or  moving  on  the  other  track. 

Foundation.  The  foundations  for  mechanical  signal 
connections — pipes  and  wires — which  are  set  at 
suitable  intervals  along  the  line,  consist  usually  of 
heavy  planks,  or  of  concrete,  or  of  cast  iron. 

Frequency.  The  number  of  cycles  or  alternations  per 
second  in  an  alternating  current.  The  frequencies 
most  used  in  commercial  work  are  25  and  60  cycles 
per  second. 

Frequency  Changer.  A  piece  of  apparatus  for  chang- 
ing from  one  frequency  to  another,  consisting  of 
a  motor  driving  either  an  ordinary  alternating  cur- 
rent generator  or  a  machine. 

Frequency  Converter.  A  machine  for  converting  from 
an  alternating  current  system  of  one  frequency  to 
an  alternating  current  system  of  another  frequency. 

Frequency  of  Alternation.     The   number    of  cycles  or 
periods  executed  by  an  alternating  current  in  unit 
time.      The    periodicity.      The    two    standard    fre-' 
quencies  are  now  25  and  60. 

Frequency  Relay.  An  alternating  current  relay  so  made 
that  it  will  act  effectively  only  when  energized  by 
an  alternating  current  of  a  certain  frequency. 

Front  Contact  (of  a  relay).  An  electrical  contact 
which  is  made  when  the  armature  of  the  relay  is 
attracted  to  the  pole  piece  6f  the  magnet  coils  by 
current  flowing  through  the  coils.  See  Relay  and 
Back  Contact. 

Front  Locking.  The  mechanical  locking  in  a  "Stand- 
ard" interlocking  machine  which  acts  in  a  plane 
outside  of  the  tappets.  See  Figs.  853-902. 

Front  Rod.     See  Switch.     See  Figs.  1532-1542. 

Frost  Board.  In  a  battery  chute  or  well  a  cover  be- 
neath the  main  cover  more  effectually  to  protect 
the  battery  from  freezing.  See  Figs.  2370,  2371, 
2372,  2374,  2375-2382,  2383-2387,  2396,  2397,  2399, 
2400,  2405-2406. 

Function.     See  Operated  Unit. 

Fuse.  In  electrical  work  a  strip,  plate  or  bar  of  some 
readily  fusible  alloy,  designed  to  melt,  and  thus 
break  the  circuit  in  which  it  is  placed,  if  a  current 
passes  which  is  of  sufficient  power  to  melt  it.  The 
fuse  is  so  designed  as  to  melt  before  the  current 
is  powerful  enough  to  endanger  apparatus  in  other 
parts  of  the  circuit.  The  melting  of  the  fuse  is 
due  to  the  heat  generated  by  the  passage  of  the 
current.  Fuses  are  sometimes  enclosed  in  glass 


tubes,  or  are  placed  between  mica  strips  to  prevent 
injury  to  surrounding  apparatus.  A  cartridge  fuse 
consists  of  a  piece  of  metal  as  above,  surrounded 
by  some  chemical  compound,  the  purpose  of  which 
is  to  extinguish  any  arc  that  might  form  when  the 
fuse  "blows." 

Fusee.  A  chemical  fire  light,  like  a  roman  candle,  giv- 
ing a  bright  light — red  or  green  or  yellow — as  a 
stop  or  slow  signal.  The  fusee  is  thrown  off  the 
rear  of  a  train  as  a  warning  to  any  following  train. 
Its  stick  has  a  sharp  point,  and  it  can  be  thrown  so 
as  to  stand  upright.  It  is  made  to  burn  a  definite 
length  of  time,  either  five  or  ten  minutes.  At  the 
end  of  that  time  it  is  reduced  to  ashes.  It  is  the 
only  practicable  stop  signal  in  use  which  can  be 
effectively  given  at  will  from  a  moving  train.  See 
Time  Interval  System. 

G 

Gain  Stroke.  A  device  for  securing  extra  stroke  in  a 
line  of  connections  used  at  the  end  of  a  long  wire 
line  where  elasticity  and  lost  motion  have  reduced 
the  throw.  It  usually  consists  of  a  crank  having 
arms  of  different  length;  an  escapement  crank,  a 
special  jaw  or  a  system  of  pulleys.  See  41,  42,  43, 
Figs.  1047-1121;  Figs.  1172-1173,  1348-1349. 

Galvanometer.  An  apparatus  for  measuring  the 
strength  of  an  electric  current  by  the  deflection  of 
a  magnetic  needle.  A  current  measurer. 

The  galvanometer  depends  for  its  operation  on 
the  fact  that  a  conductor,  through  which  an  elec- 
tric current  is  flowing,  will  deflect  a  magnetic 
needle  placed  near  it.  This  deflection  is  due  to 
the  magnetic  field  caused  by  the  current. 

The  needle  is  deflected  by  the  current  from  a 
position  of  rest,  either  in  the  earth's  magnetic  field 
or  in  a  field  obtained  from  a  permanent  or  an  elec- 
tromagnet. In  the  first  case,  when  in  use  to  meas- 
ure a  current,  the  plane  of  the  galvanometer  coils 
must  coincide  with  the  planes  of  the  magnetic 
meridian.  In  the  other  case,  the  instrument  may 
be  used  in  any  position  in  which  the  needle  is  free 
to  move. 

Galvanometers  assume  a  variety  of  forms  accord- 
ing either  to  the  purposes  for  which  they  are  em- 
ployed, or  to  the  manner  in  which  their  deflections 
are  valued. 

Gassing.  The  evolution  of  gas  from  the  plates  of  a 
secondary  or  storage  battery. 

Generator,   Electric.     See   Dynamos.     See   Figs.   2860- 


Gravity  Cell.  A  common  form  of  primary  cell  using 
zinc  and  copper  as  the  elements  and  a  solution  of 
zinc  sulphate  and  copper  sulphate  for  the  electro- 
lyte. The  zinc  in  the  form  of  an  open  wheel  or 
crowfoot  is  suspended  in  the  top  of  the  jar  and 
the  copper  in  the  form  of  a  cylinder  or  star  rests 
on  the  bottom  and  is  surrounded  with  crystals  of 
blue  vitriol  (copper  sulphate).  The  solution  of 
copper  sulphate,  being  heavier  than  the  solution  of 
zinc  sulphate,  sinks  to  the  bottom,  hence  the  name, 
gravity  cell.  The  reaction  which  takes  place  on  a 
closed  circuit  is  very  simple.  The  copper  sulphate 
is  decomposed,  depositing  metallic  copper  on  the 
copper  plate,  and  the  sulphuric  acid  thus  liberated 
attacks  the  zinc  plate,  yielding  zinc  sulphate.  There 
is  a  distinct  line  of  demarcation  between  the  two 
liquids  of  the  electrolyte,  and  the  best  test  of  the 
condition  of  the  battery  is  by  observing  when  the 
zinc  sulphate  solution  increases,  extending  down 


i8 


THE   SIGNAL  DICTIONARY 


Gri-Ind 


near  the  copper,  denoting  an  excess  of  zinc  and  a 
deficient  amount  of  copper  sulphate.  The  zinc 
solution  should  then  be  drawn  off  and  more  copper 
sulphate  solution  added.  This  is  done  through  a 
tube,  so  as  not  to  disturb  the  equilibrium  of  the 
liquids.  The  zinc  must  be  renewed  occasionally 
and  the  copper  taken  out  and  cleaned.  A  copper 
plate  made  unwieldy  by  accretions  of  copper  must 
be  replaced.  The  ordinary  gravity  cell  has  a  volt- 
age of  about  0.9  volt,  and  will  remain  active  for 
long  periods  without  appreciable  polarization  on  £ 
closed  circuit.  For  this  reason  it  is  almost  uniA 
versally  used  for  supplying  current  to  track  circuits 
in  signal  work  and  for  telegraph  circuits  where, 
small  amounts  of  current  at  low  voltage  are  re- 
quired. See  Figs.  2297-2324. 

Grid.     See  Resistance.     See  also  Figs.  678-679. 

Ground.  Connection  of  an  electric  conductor  to  earth, 
usually  by  attaching  it  to  a  metal  plate  or  cone, 
buried  in  the  ground.  The  term  is  commonly  use-1 
in  referring  to  an  accidental  connection  of  a  cir- 
cuit with  the  ground  or  any  large  object  in  which 
the  current  is  dissipated.  See  Figs.  2765-2767, 
2787,  2788. 

Ground  Lever.  A  switch  or  signal  lever  arranged  to  be 
handled  by  a  person  on  the  ground,  as  at  an  out- 
lying switch  or  a  derail,  in  distinction  from  a  leve- 
of  an  interlocking  machine  in  a  tower.  See  Figs. 
3495-3510. 

Ground  Signal  Post.  An  ordinary  signal  post,  as  dis- 
tinguished from  one  on  a  bridge,  bracket  post  or 
other  structures  above  the  ground. 

H 

Harmonic  Currents.  Periodically  alternating  currents 
varying  harmonically.  Currents  which  are  har- 
monic functions  of  time.  Sinusoidal  currents. 

Head  Block.  The  long  tie  or  sleeper  on  which  the 
points  of  a  switch  rest. 

Head  Rod.  The  rod  next  to  the  front  rod  of  a  switch, 
which  see. 

High  Signal.  A  general  term  applied  to  all  full-sized 
semaphore  signals  mounted  on  a  post,  bridge,  build- 
ing or  other  structure  above  the  level  of  the  top 
of  a  car  or  locomotive.  When  two  or  more  high 
arms  are  fixed  on  the  same  post,  the  lowest  one  is 
usually  placed  at  a  minimum  height  of  twenty  feet 
above  the  level  of  the  rails  and  a  minimum  vertical 
distance  of  six  feet  is  preserved  between  the  sig- 
nals on  the  same  post.  All  signals  for  trains  run- 
ning at  full  speed  are  high.  Low  signals  (dwarf) 
are  used  only  for  slow  movements.  See  Dwarf  Sig- 
nal, Pot  Signal,  Semaphore  Signal. 

Highway  Crossing  Signal.  Usually  some  form  of  elec- 
tric bell,  which  see,  mounted  on  a  post  near  a 
highway  crossing.  Used  to  announce  the  approach 
of  trains.  See  Figs.  2089-2242. 

Home  Signal.  A  fixed  signal  at  the  point  at  which 
trains  are  required  to  stop  when  the  route  is  not 
clear.  As  a  block  signal  it  stands  at  the  entrance 
to  the  block.  At  interlocking  plants  home  signals 
stand  immediately  in  the  rear  of  the  switches,  de- 
rails, crossings  and  drawbridges  which  they  pro- 
tect. A  home  signal  of  an  interlocking  plant,  when 
cleared,  denotes  that  the  route  governed  by  tin? 
signal  has  been  made  ready  for  a  train  movement 
over  it.  The  term  home  signal  was  originally  ap 
plied  on  British  railways  to  the  signal  mounted  or. 


or  near  the  signal  box,  controlling  the  entrance  of 
trains  into  a  block  section. 

A  home  block  signal  in  a  manual  or  controlled 
manual  system,  when  in  the  stop  position,  must  not 
be  passed  except  on  receipt  of  the  proper  author- 
ity, either  written  or  by  flag,  obtained  from  the  sig- 
nalman. An  automatic  home  block  signal,  when  in 
the  stop  position,  indicates  "Stop,  wait  (a  specified 
length  of  time)  and  proceed  cautiously,  expecting 
to  encounter  obstruction."  See  Permissive  Block 
Signaling.  Home  block  signals,  when  in  the  clear 
position,  indicate  "Proceed;  block  is  clear." 

Semaphore  home  signal  arms  are  usually  made 
with  square  ends  to  distinguish  them  from  Distant 
Signals  (which  see),  the  arms  of  which  are  made 
with  forked  or  "fish-tail"  ends.  On  many  roads  a 
further  distinction  is  made  by  using  arms  with 
pointed  ends  for  automatic  home  block  signals  and 
square  end  arms  for  all  other  home  signals. 

In  Three-Position  Automatic  Block  Signaling, 
which  see,  the  functions  of  the  home  signal  and 
the  distant  signal  are  combined  in  a  single  arm. 
See  Figs.  225-307.  See  Distant  Signal,  Advance 
Signal,  Dwarf  Signal,  Night  Signal  Indications, 
Starting  Signal. 

Home  Track  Circuit.  That  track  circuit  which  governs 
the  indication  of  the  home  signal.  It  prevents  the 
home  signal  being  cleared  while  any  part  of  train 
is  between  home  and  advance  block  signals.  It  is 
located  between  home  and  advance  block  signals. 

Horizontal  Chain  Wheel.  A  chain  wheel  whose  axis 
is  vertical.  Used  to  change  the  direction  of  a  wire 
line.  See  Figs.  1338-1367,  I37*-I39O. 

Horizontal  Locking.  Mechanical  locking  arranged  in  a 
horizontal  plane.  See  Saxby  &  Farmer,  Stevens 
and  Dwarf  Interlocking  Machines.  See  Figs,  790- 
850,  1004-1006. 

Horsepower.  A  commercial  unit  of  power,  activity, 
or  rate-of-doing-work.  A  rate-of-doing-work  equal 
to  33,000  foot  pounds  per  minute. 

Horsepower,  Electric.  Such  a  rate-of-doing  electrical 
work  as  is  equal  to  746  watts,  or  746  volt-coulombs 
per  second. 

Hysteresis.  A  lagging  behind  of  magnetization  rela- 
tive to  magnetizing  force.  Apparent  molecular 
friction  due  to  magnetic  change  of  stress.  A  re- 
tardization  of  the  magnetizing  or  demagnetizing 
effects  as  regards  the  causes  which  produce  them. 
That  quality  of  a  paramagnetic  substance  by  virtue 
of  which  energy  is  dissipated  on  the  reversal  of  its 
magnetization. 

I 

Illuminated  Track  Diagram.  See  Track  Indicator.  See 
Figs.  2615,  2625-2629. 

Impedance.  The  apparent  resistance  in  an  alternating 
current  circuit  containing  both  resistance  and  re- 
actance. The  total  effect  tending  to  retard  the.  flow 
of  current.  The  vector  sum  or  square  root  of  th.? 
sum  of  the  squares  of  the  resistance  and  reactance 
in  such  a  circuit. 

Impedance  Bond.     Sec  Inductive  Bond. 

Impedance  Coils.  A  term  sometimes  applied  to  chok- 
ing coils,  reactance  coils,  or  economy  coils. 

In  Advance  of  a  Signal.  The  section  of  track  occupied 
by  a  train  that  has  passed  a  signal. 

Indication,  (i)  The  indication  of  a  visual  signal  is  what 
it  tells  the  approaching  enginemen.  (2)  In  a  power 
interlocking  machine  the  indication  is  the  electro- 


Ind-Joh 


magnetic  or  pneumatic  action  produced  in  the  ma- 
chine after  a  switch  or  a  signal  has  been  moved, 
indicating,  by  releasing  a  lock  on  one  or  more 
levers,  that  the  switch  movement  or  the  signal 
movement  actually  has  been  completed. 

Indicator.  See  Block  Indicator,  Switch  Indicator,  Track 
Indicator,  Signal  Repeater.  See  Figs.  2550-2674. 

Induced  Currents.  Currents  produced  in  a  closed  cir- 
cuit by  the  effects  of  a  changing  magnetic  field. 
Induced  currents  may  be  produced  in  one  circuit 
by  increasing  or  decreasing  the  current  in  a  neigh- 
boring circuit,  or  by  causing  a  clo.sed  circuit  to  cut 
a  magnetic  field. 

Inductance.  The  capacity  for  induction  of  a  circuit  on 
itself  or  other  circuits;  self-induction — that  prop- 
erty by  virtue  of  which  an  electromotive  force  act-- 
ing on  the  circuit  does  not  immediately  generate 
the  full  current  which  it  is  capable  of  producing  in 
that  circuit,  and  which  when  the  electromotive  force 
is  withdrawn  requires  time  for  the  current  strength 
to  fall  to  zero.  The  quality  by  virtue  of  which  the 
passage  of  an  electric  current  is  necessarily  accom- 
panied by  the  absorption  of  electric  energy  in  the 
formation  of  a  magnetic  field.  A  constant  quantity 
in  a  circuit  at  rest  and  devoid  of  iron  depending 
solely  on  its  geometric  arrangement.  Inductance 
is  usually  expressed  in  henrys. 

Inductance  Coil.  An  impedance,  reactance,  or  chok- 
ing coil.  A  coil  placed  in  a  circuit,  for  the  purpose 
of  preventing  an  impulsive  current-rush  in  that  cir- 
cuit, by  means  of  the  counter  electromotive  force 
developed  in  the  coil  on  being  magnetized. 

Induction.  The  influence  exerted  by  a  charged  body 
or  by  a  magnetic  field,  on  neighboring  bodies  with- 
out apparent  communication.  See  Induced  Cur- 
rents and  Inductance. 

Induction  Motor.  A  term  usually  applied  to  an  a.  c. 
motor  having  a  short-circuited  armature,  and  a 
stator  wound  to  give  the  effect  of  a  revolving  flux, 
causing  the  rotor  to  be  revolved  by  the  force  of  at- 
traction due  to  the  induced  currents  in  the  short- 
circuited  armature.  See  Squirrel  Cage  Armature. 

Inductive  Bond.  In  track  circuits,  a  bond  between  con- 
tiguous rails  of  the  track  (the  rails  being  insulated 
from  each  other  by  the  usual  non-conducting  ma- 
terial between  their  ends),  consisting  of  a  coiled 
conductor,  so  arranged  that  the  induction  taking 
place  in  the  coils,  on  the  passage  of  an  alternating 
current,  will  impede  the  flow  of  that  current,  while 
at  the  same  time  the  passage  of  a  direct  current  is 
not  impeded.  Thus  the  insulation  in  the  joint  is 
made  of  no  effect  as  regards  the  direct  current 
(used  for  propulsion  of  train),  while  it  still  is  effec- 
tive as  regards  the  alternating  current  used  for 
signaling.  See  Figs.  604-605,  639,  641,  643,  648,  653- 
655,  666,  671,  and  Figs.  2981-2982. 

Inductive  Track  Bond.     See  Inductive  Bond. 

Inside  Connected  Facing  Point  Lock.  See  Facing 
Point  Lock,  and  Figs.  1479,  1480. 

Insulated  Rail  Joint.  The  term  rail  joint  is  used  to  de- 
note the  bars  or  plates  and  bolts  used  in  a  rail- 
way track  to  fasten  together  the  ends  of  contigu- 
ous rails.  An  insulated  joint  is  one  in  which  a  non- 
conducting body  (fiber),  about  l/±  in.  thick,  called 
an  end  post,  is  placed  between  the  ends  of  the 
.rail,  and  plates  or  strips  of  the  same  material 
around  the  bars  and  bolts  so  as  to  prevent  electric 
current  from  passing  from  one  rail  to  the  other. 
Fiber  plates-placed  below  one  or  both  of  the  rails 
are  called  mats  or  sole  plates.  Sometimes  wooden 


blocks,  called  wooden  fillers,  are  placed  against  the 
rails  in  place  of  or  in  addition  to  the  iron  bars. 
Insulated  rail  joints  are  used  at  the  ends  of  track 
circuits.  See  Figs.  3628-3644. 

Insulated  Switch  Rod.  A  rod,  connecting  the  two  rails 
of  a  switch  in  a  railway  track,  which  is  divided  into 
two  parts,  and  the  parts  held  together  by  a  sub- 
stance which  is  a  non-conductor  of  electricity. 
Used  in  switches,  the  rails  of  which  are  traversed 
by  electric  circuits.  See  Figs.  3653-3654,  3659-3660, 
36/5-3677,  3680-3688. 

Insulation.  The  protection  of  electrical  conductors 
from  other  conducting  substances  and  from  the 
ground.  See  Wires. 

Interlocking.  "An  arrangement  of  switch,  lock  and 
signal  appliances  so  interconnected  that  their  move- 
ments must  succeed  each  other  in  a  predetermined 
order."  (A.  R.  A.)  The  term  includes  the  tower, 
the  machine,  the  switches  and  signals  and  all  the 
connections  and  appurtenances.  See  Interlocking 
Plant. 

Interlocking  Machine.  An  assemblage  of  switch  levers 
and  signal  levers,  in  a  frame,  with' connections  so 
arranged  that  the  movement  of  a  lever,  or  its  un- 
locking, preparatory  to  its  movement,  may  be  made 
to  lock  any  or  all  other  levers  in  the  frame.  The 
interlocking  is  used  to  insure  the  movement  of 
levers  always  in  a  predetermined  order,  thus  pre- 
venting the  giving  of  a  conflicting  or  dangerous 
signal  indication  by  mistake  or  inadvertence.  The 
most  common  form  of  interlocking  machine  is  the 
Saxby  &  Farmer,  Figs.  790-850.  Others  are  the 
Johnson,  Figs.  903-932;  the  "Standard,"  Figs.  851- 
902;  the  National,  Figs.  933-1003;  the  Stevens,  Fig. 
roo6,  and  several  dwarf  machines,  Figs.  1004-1005. 
Machines  in  which  switches  and  signals  are  moved 
by  hand-power  (called  "mechanical")  have  latch 
locking,  which  see.  See  Power  Interlocking  Ma- 
chine, pages  210-279. 

Interlocking  Plant.  A  group  of  interlocking  functions 
controlled  from  one  interlocking  machine,  the  ma- 
chine and  all  its  accessories.  See  Interlocking, 
pages  134-296;  Figs.  740-2088. 

Interlocking  Relay.  Two  relays  on  a  single  base,  so 
arranged  that  the  armature  of  one  can  be  made  to 
lock  that  of  the  other,  either,  in  its  closed  or  its 
open  position.  See  Figs.  2119-2145. 

Interlocking  Station.  A  place  from  which  an  inter- 
locking plant  is  operated;  usually  a  cabin  or  tower 
(see  Figs.  3884-3908),  the  principal  room  being 
that  occupied  by  the  signalman  and  containing  the 
interlocking  machine. 

Intermittent  Current.  A  current  that  does  not  flow  con- 
tinuously, but  which  flows 'and  ceases  to  flow  at 
intervals,  so  that  electricity  is  practically  alter- 
nately present  and  absent  from  the  circuit. 

Ionize  (verb).  To  break  into  ions.  Ions  are  electro- 
positive particles  of  matter  smaller  that  atoms. 
See  Mercury  Arc  Rectifier. 

Ions.  The  groups  of  atoms  or  radicals  into  which  a 
molecule  is  separated  by  electrolytic  decomposi- 
tion. 


J 


Jaw.  A  forging  attached  to  a  pipe  line  for  connecting 
it  with  the  machine  or  with  a  crank,  a  compensa- 
tor, or  any  other  device.  See  Figs.  1026-1121. 

Johnson  Interlocking  Machine.  An  interlocking  ma 
chine  with  the  locking  bars  and  tappets  arranged 
in  a  vertical  plane  beneath  the  floor.  See  Figs. 


2O 


THE   SIGNAL  DICTIONARY 


Jum- Lin 


903-932.  This  style  was  first  made  in  America  by 
the  Johnson  Railroad  Signal  Company  in  1889. 

Jump  Spark.  A  disruptive  spark  obtained  between  two 
opposed  conducting  surfaces,  as  distinguished  from 
a  spark  obtained  by  or  following  a  wiping  con- 
tact. 

Jumper.  A  temporary  shunt  or  short-circuit  in  a  series 
connected  circuit.  Commonly  used  in  track  cir- 
cuit work  to  preserve  the  continuity  of  the  track 
circuit  past  a  section  of  track  such  as  a  crossing  or 
electrified  tracks  where  the  wires  cannot  be  suitably 
insulated. 

Junction  Box.  A  box  to  which  are  run  a  number  of 
electrical  conductors  for  convenient  connection, 
disconnection,  inspection,  or  change  of  connections. 
See  Figs.  3/01-3883. 

K 

K.W.     Abbreviation  for  Kilowatt. 

Kilowatt.  Commonly  abbreviated  to  k.w.  One  thou- 
sand Watts,  which  see.  The  common  unit  of  rating 
for  the  output  of  electric  generators.  One  horse- 
power equals  .746  k.w. 

Kilowatt  Hour.  The  common  unit  of  work  as  applied 
to  electrical  machinery,  equal  to  the  expenditure  of 
one  kilowatt  for  one  hour. 

Knife  Switch.  A  common  form  of  switch  for  making 
or  breaking  an  electrical  circuit,  consisting  of  a 
blade  like  the  blade  of  a  knife,  which  may  be  pushed 
between  two  spring  contacts.  It  is  pivoted  at  one 
end,  and  has  a  non-conducting  handle.  Single  or 
multiple  blades  may  be  used,  all  attached  to  the 
same  handle.  A  switch  may  be  either  single  or 
double  throw.  See  Figs.  2504,  2508,  2510. 

L 

Lag.  The  phase  difference  of  one  alternating  current 
behind  another  or  of  one  function  of  an  alternating 
current  behind  another  function,  as  current  and 
voltage. 

Lagging  Current.  A  periodic  current  lagging  behind 
.the  impressed  electromotive  force  which  pro- 
duces it. 

Laminated  Core.  An  iron  core  that  has  been  sub- 
divided in  planes  parallel  to  its  magnetic  flux- 
paths,  in  order  to  avoid  the  injurious  production 
of  Foucault  or  eddy  currents. 

Lamination.  The  sub-division  of  an  iron  core  into 
laminae. 

Lamp  Signal.  A  common  form  of  lamp  for  fixed 
signals  is  a  rectangular  sheet  metal  case,  with  a 
magnifying  lens  on  the  front  side,  and,  if  needed, 
a  small  glass-covered  opening  on  the  back  side  to 
enable  the  signalman  or  inspector  to  know  whether 
the  light  is  burning.  The  light  may  be  secured 
from  kerosene,  acetylene,  gas,  or  electricity.  For 
signals,  such  as  clockwork  signals,  which  turn  on 
a  vertical  spindle  or  shaft,  the  lamp  has  lenses  on 
all  four  sides,  two  opposite  each  other,  giving  the 
clear  indication  and  the  two  others  opposite  to 
each  other  giving  the  stop  indication.  See  Long- 
Time  Burner;  Back  Light.  See  Figs.  2675-2743. 

Lampman.  The  person  who  cleans,  fills  and  cares  for 
the  lamps  of  signals.  Ordinary  lamps  are  usually 
lighted  and  put  in  position  each  afternoon  and 
taken  down  and  extinguished  each  morning. 
Lamps  with  "long-time"  burners  remain  in  place, 
lighted,  continuously  for  several  days  and  night*. 

Lantern.     A  cage  or  body  surrounding,  protecting  and 


equipped  with  a  lamp  or  other  source  of  illumina- 
tion. See  Figs.  2675-2743. 

Lap  Sidings.  On  a  single-track  railway,  an  arrange- 
ment of  two  side  tracks  the  ends  of  which  overlap 
each  other.  Siding  A  being  west  of  the  station, 
on  the  south  side  of  the  main  line,  and  siding  B 
east  of  the  station,  on  the  north  side,  track  A  is 
continued  a  short  distance  east  of  the  station  and 
track  B  a  short  distance  west  of  it.  Thus  if  two 
freight  trains  are  held  at  the  station  to  clear  the 
main  line  for  a  passenger  train,  the  eastbound 
freight  on  track  A  and  the  westbound  on  track  B, 
it  is  practicable  for  both  of  them,  immediately  after 
the  passage  of  the  passenger  train,  to  proceed  on 
their  journeys  without  either  delaying  the  other. 

Latch  Locking.  Interlocking  of  one  lever  with  an- 
other by  means  of  the  latches  of  the  levers;  neces- 
sary in  mechanical  interlocking  to  effect  prelimi- 
nary locking.  In  grasping  a  lever  preparatory  to 
moving  it  the  signalman  unlatches  it,  and  in  so 
doing  locks  all  conflicting  levers  before  his  lever 
moves.  Other  levers  intended  to  be  released  after 
this  lever  movement  is  effected  are  unlocked  by 
the  return  of  the  latch  to  its  notch  after  the  lever 
has  completed  its  stroke.  See  Figs.  790-1003. 

Lazy- Jack  Compensator.     See  Compensator. 

Lead.  The  phase  difference  of  one  alternating  current 
ahead  of  another  or  of  one  function  of  an  alter- 
nating current  ahead  of  another  function,  as  cur- 
rent and  voltage. 

Leading  Current.  An  alternating-current  wave  or  com- 
ponent, in  advance  of  the  electromotive  force  pro- 
ducing it. 

Lead  Out.  In  an  interlocking  plant  the  pipes,  wires 
and  chains,  and  their  supports  and  accessories,  in 
and  near  the  tower  which  lead  out  from  the  tower 
to  the  switches,  signals,  etc.  See  Figs.  1007-1020. 

Lever  Locking.  The  locking  of  interlocking  switch  or 
signal  levers  by  the  movement  of  levers,  as  distin- 
guished from  latch  locking,  which  see. 

Lightning  Arrester.  A  device  to  prevent  or  reduce 
damage  to  electrical  apparatus  from  discharges 
of  lightning.  Lightning  is  a  high  potential  alter- 
nating current.  It  therefore  tends  to  jump  across 
short  gaps  especially  from  one  metallic  point  to 
another;  also  it  has  difficulty  in  flowing  through  a 
coil,  on  account  of  the  high  self-induction.  Light- 
ning arresters  are  of  two  kinds— spark  gap  and 
impedance  arresters.  The  former  consists  of  two 
or  more  metallic  plates,  with  tooth  edges  placed 
in  close  proximity  to  each  other,  one  or  more  con- 
nected to  ground,  the  others  to  the  circuit  to  be 
protected.  Impedence  arresters  consist  of  a  coil 
of  large-sized  wire  which  checks  the  lightning  dis- 
charge. Sometimes  a  ground  plate  is  placed  near 
the  coil,  so  that  the  lightning  may  jump  to  it 
and  thus  reach  ground.  See  Figs.  2744-2788. 

Line  Circuit.  The  wires  or  other  conductors  in  the 
main  line  of  a  telegraphic  or  other  circuit.  A 
transmission  circuit  for  electric  energy. 

Line  of  Force.  A  unit  of  measurement  of  the  intensity 
of  a  magnetic  field.  It  is  purely  imaginary,  but 
of  great  convenience  in  electrical  calculations. 
When  so  used  it  is  always  spoken  of,  in  connec- 
tion with  the  area  of  the  field  in  centimeters.  The 
current  generated  in  the  armature  of  a  dynamo  is 
said  to  be  due  to  the  fact  that  the  armature  coils 
cut  the  lines  of  force  of  the  magnetic  field,  and  the 
strength  of  the  current  is  proportional  to  the  num- 
ber of  lines  of  force  cut  per  second. 


Liv-Man 


THE   SIGNAL  DICTIONARY 


21 


Live  Wire.  A  wire  through  which  current  is  passing. 
A  wire  connected  with  an  electric  pressure  or 
source. 

Load-factor.  The  fraction  expressed  in  per  cent  ob- 
tained by  dividing  the  average  load  over  any  given 
period  of  time  by  the  highest  average  load  for  any 
one  minute  during  the  same  period  of  time. 

Local  Currents.  A  term  sometimes  used  for  eddy  cur- 
rents. 

Lock  and  Block.  A  common  name  for  the  Controlled 
Manual  Block  System,  which  see.  (Pages  27-45.) 

Lock,  Electric.  An  electro-magnetically  actuated  lock- 
ing dog.  The  apparatus  used  to  control  a  lever  of 
an  interlocking  machine,  switch  or  drawbridge.  It 
is  operated  by  an  electric  current.  In  interlocking 
machines  it  is  usually  applied  to  the  lever  latch 
movement.  See  Indication.  See  Figs.  2789-2812. 

Lock  Rod.  A  switch  rod  which  receives  the  plunger 
of  the  lock.  See  Switch;  Facing  Point  Lock; 
Switch  and  Lock  Movement.  See  Figs.  1522-1527, 
1532-1542,  3661-3662. 

Locking.  The  rods,  bars,  dogs,  tappets  and  other  ap- 
paratus, in  an  interlocking  machine,  by  which  the 
interlocking  is  accomplished.  See  Figs.  790-1003. 

Locking,  Electric.  The  locking  of  the  levers  of  an  in- 
terlocking machine  or  of  switches  or  drawbridges 
by  electric  locks  (which  see),  or  other  means,  to 
insure  the  integrity  of  a  route,  or  portion  of  a 
route,  during  the  movement  of  a  train  over  that 
route.  Electric  locking  is  accomplished  by  con- 
trolling the  current  for  operating  the  locks  or  other 
apparatus  by  track  circuit  relays  or  track  instru- 
ments, or  by  circuit  controllers  actuated  by  signals, 
switches,  drawbridges,  etc.  See  Figs.  2055-2088. 

Locking  Bar.  (i)  A  British  term  for  detector  bar, 
which  see. 

(2)  A  bar  running  lengthwise  in  the  interlock- 
ing machine,  to  which  the  locking  dogs  are  at- 
tached. See  Locking. 

Locking  Dog.  A  variously-shaped  block  attached  to  a 
locking  bar.  Through  it  the  interlocking  is  accom- 
plished. See  Locking. 

Locking  Sheet.  A  statement  in  tabular  form  of  th-j 
locking  operations  which  are  provided  for  in  a 
given  interlocking  machine.  It  shows  the  sequence 
in  which  levers  must  be  locked  or  unlocked  pre- 
paratory to  giving  clear  signals  for  each  route  in 
the  plant.  See  Figs.  747-788. 

Locking  Up  Track  Circuit.  That  track  circuit  used  to 
take  away  unlock  when  train  passes  advance  block 
signal  into  block  ahead.  It  is  located  just  beyond 
advance  block  signal. 

Longitudinal  Locking.  That  part  of  the  mechanical 
locking  apparatus  which  extends  longitudinally  in 
the  locking  frame.  See  Figs.  790-1004. 

Long-Time  Burner.  A  burner  used  in  signal  lamps,  in 
which  the  wick,  treated  chemically  so  as  to  make  it 
resist  rapid  combustion,  may  be  so  correctly  ad- 
justed as  related  to  the  lens  and  the  reflector  of  the 
lamp  that  the  flame  of  about  i  candle-power  will 
burn  continuously  for  from  100  to  150  hours.  With 
lamps  on  high  posts  and  scattered  over  miles  of 
territory  this  affords  a  marked  economy  in  attend- 
ance as  compared  with  lamps  needing  to  be 
trimmed  or  adjusted  every  day.  See  Lamps, 
Lanterns,  etc.,  Figs.  2675-2743. 

Lower  Quadrant.  One  of  the  quarters  of  a  circle  below 
its  horizontafaxis;  a  term  used  of  semaphore  sig- 
nals, in  which  the  arm,  normally  horizontal  (indi- 


cating stop),  is  turned  downward  to  give  ot'.er  than 
stop   indications. 

M 

M.  P.  F.     Abbreviation  for  Movable  Point  Frog. 

Machine  (verb).     To  form  by  the  aid  of  machinery. 

Machine  Framing.  The  frame  in  an  interlocking  cabin 
on  which  the  interlocking  machine  rests;  usually 
set  on  a  foundation  separate  from  that  which  sup- 
ports the  walls  of  the  building.  See  Figs.  1011-1020, 
3896-3897,  3905-3908. 

Magnet.  A  body  possessing  the  power  of  attracting 
magnetizable  bodies  like  iron  filings.  Magnets  have 
two  poles  called  north  and  south,  respectively.  The 
north  pole  of  one  magnet  will  repel  the  north  pole 
of  another  magnet,  but  will  attract  the  south  pole 
of  a  second  magnet.  A  magnet  is  said  to  possess  a 
magnetic  field  consisting  of  lines  of  force,  which  see. 
The  lines  of  force  are  assumed  in  passing  through 
the  magnetic  field  to  come  out  at  the  north  pole  and 
go  in  at  the  south  pole.  The  lines  of  force  form  .1 
closed  magnetic  circuit.  If  a  magnetizable  body  is 
brought  into  a  magnetic  field,  the  lines  of  force  are 
concentrated  on  it  and  pass  through  it.  The  body 
thereupon  becomes  magnetic  by  induction.  Sec 
Electro-Magnet. 

Magnet  Coil.  A  coil  of  insulated  wire  surrounding  the 
core  of  an  electro-magnet,  through  which  the 
magnetizing  current  is  passed. 

Magnet  Cores.  Bars  or  cylinders  of  iron  on  which 
the  magnetizing  coils  of  wire  are  placed. 

Magnetic  Clutch.  A  form  of  clutch  in  which  magnetic 
attraction  is  substituted  for  ordinary  mechanical 
force,  to  obtain  the  friction  required  in  the  clutch. 
A  clutch  operated  electro-magnetically. 

Magnetic  Field.  The  region  of  magnetic  influence  sur- 
rounding the  poles  of  a  magnet.  The  space  or 
region  traversed  by  magnetic  flux  in  which  a 
magnet  needle,  free  to  move,  will  assume  a  definite 
position. 

Magnetic  Flux.  The  number  of  lines  of  magnetic  force 
that  pass  or  flow  through  a  magnetic  circuit;  the 
total  number  of  lines  of  magnetic  force  in  any  field. 
The  magnetic  flux  is  also  called  the  magnetic  flow. 
See  Line  of  Force. 

Magnetic  Shading.  Preventing  magnetic  induction 
from  taking  place  by  interposing  a  metallic  plate 
or  a  closed  circuit  of  insulated  wire  between  the 
body  producing  the  magnetic  field  and  the  body 
to  be  magnetically  shaded;  or  by  placing  a  small 
closed  circuit  in  a  part  of  the  pole- piece  of  a  mag- 
net. See  Figs.  680-684. 

Magneto.  A  magneto-generator.  A  small  magneto- 
electric  dynamo  machine. 

Maintainer.  The  person  in  immediate  charge  of  the 
maintenance  of  signals. 

Manifest  Train.  A  familiar  term  for  designating  the 
more  important  freight  trains;  those  of  which  the 
manifests  or  waybills  are  specially  recorded. 
Manual  Block  System.  A  block  system  in  which  the 
block  signals  at  a  block  station  are  moved  by  hand 
by  an  attendant,  on  information  conveyed  to  him 
from  adjacent  block  stations  by  Morse  telegraph, 
needle  telegraph,  telephone  or  single-stroke  electric 
bells  sounded  in  accordance  with  a  prescribed  code. 
The  term  "manual"  is  used  to  distinguish  such  .1 
system  from  the  Automatic  Block  Signal  System, 
which  see,  in  which  the  signals  are  worked  by  me- 
chanical or  electrical  power  controlled  automatically 
by  the  passage  of  a  train  into,  through  and  out  of  a. 


22 


THE   SIGNAL  DICTIONARY 


Max-Mor 


block  section.  The  Controlled  Manual  Block  Sys- 
tem which  see,  differs  from  the^  simple  manual  block 
system  by  the  introduction  of  electric  locking  de- 
vices attached  to  the  levers  by  which  the  signals 
are  moved,  so  that  to  clear  a  signal  admitting  a 
train  into  the  block,  the  simultaneous  action  of  the 
signalmen  at  both  ends  of  the  block  is  required. 

With  the  manual  block  system  the  blocks  are 
made  from  1,000  ft.  to  10  miles  or  more  lorg,  and 
where  the  traffic  is  light  the  station  agents  at  small 
stations,  being  telegraphers,  act  as  block  signalmen. 
The  usual  method  of  communication  in  the  United 
States  is  the  Morse  Telegraph  (which  see),  while 
in  Great  Britain  the  needle  telegraph  and  ^lectric 
bells  are  used.  Each  block  station  has  two  home 
signals,  one  to  govern  the  movement  of  trains  in 
each  direction.  On  American  single-track  lines 
the  arms  for  both  directions  are  often  placed  on  the 
same  post.  Distant  Signals  and  Advance  Signals, 
which  see,  are  also  frequently  installed.  All  of 
these  signals  are  moved  by  levers  in  the  signal 
tower  and  stand  normally  in  the  stop  position, 
being  cleared  only  on  the  approach  of  a  train,  for 
which  the  block  ahead  is  clear,  and  restored  to  the 
normal  position  after  the  train  has  passed. 

TRANSCRIPT  OF    PART  OF   A    BLOCK     SIGNALMAN'S    DAILY 
RECORD  OF  TRAINS. 


TRAIN 


/o 


Eng. 


602. 


Track  Track 


* 


Trtek 


S7S 


NOTE.— This    is    the    record    kept    at    Ki    station.  Da  is    th«- 

station   next   west   and   "Cn"  is  the   station   next  east.  This  is   for   a 

four-track    railroad.       With    a    double-track    line    the  track  number 
would-  not  be  required. 

Each  signalman  keeps  a  record  of  passing  trains 
in  the  form  substantially  like  that  shown  herewith 
for  station  Ki.  The  column  Da  shows  the  time 
trains  were  reported  as  leaving  the  next  station  to 
the  west.  The  column  Ki  shows  the  time  of  trains 
arriving  at  and  departing  from  this  station,  and  the 
column  Cn  shows  the  time  trains  were  reported  as 
leaving  the  next  station  to  the  east. 

On  some  roads  the  manual  block  system  is  used 
with  a  bell  code  in  place  of  the  telegraph.  The 
following  table  gives  the  principal  clauses  of  the 
code  of  signals  adopted  which  cover  most  of  the 
necessary  information  to  be  conveyed. 

Rings.  Meaning. 

1.  Acknowledgment  of  any  signal  except  as  noted. 

2.  Yes. 

3.  Is  block  clear?     Answer  by  2  or  5. 

4.  Train  has  entered  block. 

5.  Block   not  clear. 
2-1.  No. 

2-4.     Has  train  cleared?     Answer  4-2  or  5. 
3-3.     Train  is  on  siding  clear  of  main  track. 
3-3-3.     Train  to  you   broken    in  two.     Answer  by  repeat- 
ing  3-3-3   to   sender. 
4-2.     Track   has  cleared. 

9.     Stop  train.     Has  no  markers. 
See  Permissive  Blocking,  Absolute  Blocking. 


Maximum  Traffic  on  a  Block  Signaled  Line.  See  Block 
Signaling  for  Maximum  Traffic. 

Mechanical  Interlocking.  The  term  is  the  general  des- 
ignation for  the  machine  and  the  other  apparatus  at 
an  interlocking  plant  where  the  switches  and  signals 
are  moved  by  means  of  rods  or  wires  by  manual 
power;  distinguishing  such  a  plant  from  one  in 
which  compressed  air  or  electricity  is  the  force 
which  moves  the  switches  and  signals.  See  pages 
134-209;  Figs.  740-1761. 

Mechanical  Trip.  A  term  used  to  denote  a  trip — as 
used  in  apparatus  for  stopping  trains  without  the 
intervention  of  the  engineman — which  is  actuated 
or  controlled  by  mechanical  means,  as  distin- 
guished from  apparatus  in  which  electricity  or  mag- 
netism is  employed. 

Mechanism.  Used  as  a  general  term  for  any  mechani- 
cal or  power-operated  device  for  operating  a  signal 
or  interlocking  function  or  accessory  device  from  a 
distance.  More  specifically  used  to  refer  to  a 
signal  mechanism.  See  Figs.  512-602.  The  operat- 
ing device  for  a  switch  or  derail  is  commonly 
termed  a  movement,  which  see. 

Mechanism  Case.    The  housing  for  a  signal  mechanism. 

Megohm.     One  million  ohms.     See  Ohm. 

Mercury  Arc  Rectifier.     See -Figs.  2900-2915. 

Mercury  Contact  Relay.  A  relay,  the  armature  of 
which  closes  the  local  circuit  or  circuits  by  making 
a  contact  through  mercury.  See  Fig.  3051. 

Mil.  A  unit  of  length  equal  to  .001  in.,  used  in  measur- 
ing the  diameter  of  wire.  See  Circular  Mil. 

Mil-foot.  A  resistance  standard  consisting  of  a  foot  of 
wire,  or  other  conducting  material,  one  mil  in 
diameter.  A  standard  of  comparison  of  resistivity 
or  conductivity  of  wires. 

Milli-ammeter.     A  milli-ampere  meter. 

Milliampere.  The  one  thousandth  part  of  an  Ampere, 
which  see. 

Morse  Alphabet.  The  arbitrary  code  of  dots  and 
dashes  representing  the  letters  of  the  alphabet  used 
as  the  guide  in  making  and  breaking  the  telegraph 
circuit.  The  American  code  is  given  below. 

MORSE   TELEGRAPH    ALPHABET. 
A      -_  T        — 


B  —  -  -  , 

c  -_  _ 

D  —  -  - 

F  -__  — 

0  mmmmm 
H  .... 

1  -  - 

I  •_.•• 

X  __  _  _ 

L  ___ 

K  — .  — . 

K  — .  - 

0  .    . 

r  ...«• 

Q  —  —  —  , 

R  —   -.— 

S  --  - 


Period  (.)  -».«-»  — 

Semicolon  ( ;)  IB  mm  _  ••§ 

Comma  (,)  ••  «~  —  mm 

Interrogation  ( t)  •••  ••  •  ^HK 

Exclamation  ( !)•  •_•  mm  mm* 

Paragraph  fll)  mm  mm  mm 

FtiTDthc.il  ()  tmmmmmt 


Mor-Ohm 


THE   SIGNAL  DICTIONARY 


Morse  Telegraph.  A  method  of  communicating  be- 
tween two  distant  points  by  sending  electric  im- 
pulses over  a  wire,  the  circuit  being  made  and 
broken  according  to  the  Morse  Alphabet,  which 
see.  The  signals  thus  formed  are  received  and 
made  audible  by  an  electro-magnetic  sounder  or 
receiver.  Invented  in  1837  by  S.  F.  B.  Morse. 
First  used  publicly  in  1844.  See  Needle  Telegraph. 
See  Figs.  3546-3548. 

Motor,  Electric.  A  device  for  transforming  electrical 
power  into  mechanical  power.  All  practical  electric 
motors  depend  for  their  operation  on  the  tendency 
to  motion  in  a  magnetic  field  of  a  conductor  carry- 
ing a  current  or  on  magnetic  attraction  or  repul- 
sion. The  entire  magnetism  may  be  produced  by 
the  current,  or  part  may  be  obtained  from  perma- 
nent magnets  and  the  rest  from  electro-magnets 
(Houston).  See  Figs.  531-532,  544.  558,  572,  2860- 
2866,  2869-2870,  2886-2887. 

Motor-generator.  A  motor  coupled  to  a  generator. 
See  Figs.  2861,  2863,  2864-2866,  2869-2870,  2886-2887. 
A  motor-dynamo.  A  transforming  device. 

Movement.  Common  term  applied  to  the  mechanical 
or  power-operated  device  for  moving  a  switch,  de- 
rail, detector  bar  or  other  device  in  the  track,  from 
a  distant  point. 

Multiple  (Electricity).  T*wo  or  more  pieces  of  electrical 
apparatus,  such  as  batteries,  indicators,  lamps, 
motors  or  contact  points,  are  said  to  be  connected 
in  multiple  when  they  are  connected  across  two 
mains  leading  from  the  source  of  supply.  A  part 
of  the  current  flows  through  each  lamp,  motor  or 
other  function.  Pieces  of  apparatus  thus  connected 
are  also  said  to  be  connected  in  parallel. 

Multiple  Circuit.  A  circuit  in  which  a  number  of  sepa- 
rate sources  or  separate  receptive  devices,  or  both, 
have  all  their  positive  poles  connected  to  a  single 
positive  lead  or  conductor,  and  all  their  negative 
poles  connected  to  a  single  negative  lead  or  con- 
ductor. 

Multiple-series  Circuit.  A  circuit  in  which  a  number 
of  separate  sources,  or  receptive  devices,  or  both, 
are  connected  in  a  number  of  separate  groups  in 
series,  and  these  separate  groups  subsequently  con- 
nected in  multiple. 

N 

National  Interlocking  Machine.  An  interlocking  ma- 
chine having  vertical  locking  arranged  in  a  frame 
below  the  floor.  Originally  made  by  the  National 
Signal  Company.  See  Figs.  933-1003. 

Needle  Telegraph.  An  apparatus  by  which  signals 
transmitted  from  one  point  are  received  at  the 
other  end  of  the  line  by  observing  the  movements 
to  the  right  or  left  of  a  vertical  needle  over  a  dial. 
The  single  needle  apparatus  of  Wheatstone  consists 
of  an  astatic  needle  mounted  inside  a  double  co'l 
of  fine  wire  connected  to  the  external  circuit  and 
free  to  rotate  on  a  horizontal  axis,  carrying  on  its 
end  the  pointer,  projecting  through  the  dial.  The 
needle  is  made  to  turn  to  the  right  or  left  by  re- 
versing the  direction  of  the  current  flowing  through 
the  coil  and  the  external  circuit.  The  sender  con- 
sists of  a  double  key  or  tapper.  Depressing  one 
key  sends  a  negative  current  through  the  line  and 
turns  the  needle  to  the  right.  Depressing  the  other 
key  sends  a  positive  current  from  the  battery 
through  the  line  and  deflects  the  needle  to  the  left. 
The  movement  of  the  needle  to  the  left  indicates 
a  dot  in  the  Morse  Alphabet,  which  see,  and  a  move 


to  the  right  indicates  a  dash.  In  Great  Britain  the 
needle  telegraph  is  used  in  manual  block  signaling 
between  adjoining  signal  cabins.  An  elaborate  bell 
code  is  usually  used  in  conjunction  with  it.  See 
Morse  Telegraph. 

Neutral  Relay.  An  ordinary  direct  current  electro- 
magnetic relay,  workable  by  a  direct  current,  re- 
gardless of  the  polarity  of  the  current.  See  Figs. 
3044-3075,  3078. 

Night  Signal  Colors.  Uutil  within  a  few  years  the  gen- 
eral practice  with  signal  lights  throughout  the 
United  States  was  white  (an  ordinary  oil-lamp 
flame)  for  clear  or  proceed,  green  for  caution  (both 
for  permissive  block  signaling  and  for  the  adverse 
indications  of  distant  signals),  and  red  for  stop. 
Since  1899  the  green-yellow-red  system  has  gained 
favor;  green  for  clear  or  proceed,  yellow  for  adverse 
distant  and  red  for  stop.  In  Great  Britain  green 
has  been  the  "clear"  color  universally  for  15  years 
or  more;  but  yellow  is  not  used,  as  in  that  country 
distant  signals  usually  have  the  same  night  colors 
as  home  signals.  On  the  Chicago  &  North-West- 
ern for  many  years  green  has  been  the  "clear"  color, 
and  the  adverse  distant  signal  is  given  by  a  green 
and  red  light  side  by  side.  A  number  of  roads  have 
abandoned  red  as  the  stop  indication  in  dwarf  sig- 
nals and  have  substituted  purple  or  blue.  These 
colors  are  practicable  at  the  short  distances  which 
dwarf  signals  have  to  be  seen.  See  Figs.  229-276. 

Normal.  The  position  in  which  a  lever  in  an  interlock- 
ing machine  stands  when  the  corresponding  switch 
or  signal  is  in  its  normal  position.  A  switch  is 
"normal"  when  set  for  the  main  track;  a  derailing 
switch  is  normal  when  set  to  derail;  a  home  signal 
when  it  indicates  stop;  a  distant  signal  when  it  in- 
dicates caution.  Automatic  block  signals  in  their 
simplest  form  are  called  "normal  clear,"  as  at  all 
times  when  their  block  sections  are  unoccupied 
with  the  switches  closed  and  all  apparatus  in  order 
the  home  signals  stand  at  "clear,"  indicating  "pro- 
ceed." In  a  modified  arrangement,  called  "Normal 
Danger,"  the  home  signals  indicate  "stop"  at  all 
times  (even  when  the  block  is  clear),  except  when 
a  train  is  approaching,  and  then  they  indicate  "pro- 
ceed" only  in  case  the  block  is  clear.  The  practice 
thus  resembles  the  practice  in  manual  signaling, 
where  home  signals  are  always  kept  in  the  stop 
position  except  when  it  is  necessary  to  clear  them 
for  the  passage  of  a  train.  On  a  double-track  or  a 
four-track  railway  the  normal  movement  of  trains, 
on  a  given  track,  is  that  in  which  trains  regularly 
run  on  that  track.  By  special  order  of  the  train 
dispatcher  trains  may  be  moved  in  the  opposite  di- 
rection against  the  "current  of  traffic." 

o 

Off.  In  operating  signals,  a  two-position  semaphore 
signal,  when  in  the  position  indicating  proceed 
(either  at  full  speed,  as  at  a  home  signal,  or  other- 
wise, as  at  a  distant  signal)  is  said  to  be  "off/ 
When  in  the  other  position  the  signal  is  said  to  be 
"on."  This  term  is  common  in  Great  Britain,  but 
not  common  in  America. 

Ohm.  The  unit  of  electric  resistance.  Such  a  resist- 
ance as  would  limit  the  flow  of  electric  current 
under  an  electromotive  force  of  i  volt  to  i  ampere. 
The  standard  of  measurement  is  the  resistance  of  a 
column  of  pure  mercury  I  square  millimeter  in 
cross-section  and  106  centimeters  long  at  a  tem- 
perature of  o  deg.  Cent,  or  32  deg.  Fahr. 


THE   SIGNAL  DICTIONARY 


Ohm-Ove 


Ohmmeter.  An  instrument  for  measuring  directly  in 
terms  of  ohms  unknown  resistances.  See  Figs. 

3539-3541- 

E 

Ohm's  Law.     The  expression  I  =  —  is  commonly  called 

R 

Ohm's  law.  It  shows  the  relation  between  current, 
voltage  and  resistance  in  a  D.C.  circuit  or  an  A.C. 
circuit  containing  no  inductance  or  capacity.  It 
may  be  expressed  as 

Volts  Volts 

Amperes  =  —     — ,  Ohms  =  —          — ,  or  Volts  — 

Ohms  Amperes 

Amperes  X  Ohms.     See  Ampere. 

Oil  Crank  Box.  A  water-tight  box,  in  which  a  crank  is 
pivoted.  It  is  filled  with  oil  and  used  in  connection 
with  oil  pipes,  which  see.  See  also  Figs.  1425- 
1444. 

Oil  Pipe.  A  pipe  within  which  a  wire  or  a  second  pipe 
for  the  operation  of  an  interlocking  function  is  laid 
where  it  must  run  underground,  as  at  a  highway 
crossing.  After  the  insertion  of  the  operating  pipe 
or  wire  the  remaining  space  is  filled  with  oil  to 
reduce  friction  and  exclude  moisture.  Stuffing 
boxes  are  provided  at  each  end  to  prevent  the  es- 
cape of  the  oil.  See  Figs.  1421-1444. 

Oil  Transformer.  A  transformer  immersed  in  oil  in 
order  to  insure  and  maintain  high  insulation.  An 
oil-insulated  transformer. 

On.  In  operating  signals,  a  two-position  semaphore 
signal,  when  indicating  stop  (as  at  a  home  signal) 
or  stop  at  the  home  signal  (as  at  a  distant  signal),  is 
said  to  be  "on."  This  term  is  common  in  Great 
Britain,  but  not  in  America.  See  Off. 

Open  Circuit.  A  term  used  to  designate  an  electric 
circuit  normally  broken  at  one  or  more  points;  as, 
for  example,  the  ordinary  door-bell  circuit,  which  is 
always  open  at  the  push  button  except  when  a  con- 
tact is  completed  at  that  point,  by  pressing  the 


has  declared  each  of  the  following  to  be  one  unit' 
One  signal  arm;  one  pair  switch  points;  one  derail; 
one  pair  movable  frog  points;  one  5o-ft.  detector 
bar,  with  lock;  one  lock;  one  scotch  block;  one  tor- 
pedo machine;  one  electric  lock;  one  annunciator 
or  indicator  for  one  route.  A  committee  of  signal 
officers  of  the  New  York  Central  Lines  has  adopted 
these  values,  except  that  a  detector  bar  without 
lock  is  valued  at  y2  and  a  lock  (of  a  detector  bar) 
at  y2.  A  value  of  i  is  given  also  to  one  detector 
circuit  per  switch. 

Operator  (Telegraph).  On  those  American  railways 
where  the  "telegraph  block  system"  is  used  and 
where  it  is  worked  by  persons  whose  principal  oc- 
cupation has  been,  and  perhaps  continues  to  be, 
telegraphing,  the  old  title  continues  in  use,  and  the 
terms,  "operator"  and  "signalman,"  are  used  indis- 
criminately. 

Outlying  Switch.  A  switch  not  connected  with  an  in- 
terlocking plant.  Such  a  switch  may  be  locked  by 
a  key  which  is  kept  by  the  nearest  signalman,  or 
by  a  lock  controlled  from  the  nearest  signal  tower 
by  an  electric  connection.  In  some  cases  where 
neither  of  these  arrangements  is  in  force  telephone 
communication  is  maintained  between  the  switch 
and  the  nearest  signal  tower,  so  that  trainmen  using 
the  switch  can  receive  from  the  signalman  instruc- 
tions as  to  the  use  of  the  main  track. 

Outlying  Switch  Lock.  An  electric  switch  lock,  which 
see,  applied  to  an  outlying  switch,  which  see. 

Outside  Connected  Facing  Point  Lock.  See  Facing 
Point  Lock.  See  also  Figs.  1481-1483. 

Overlap.  An  arrangement  of  track  circuits  for  block 
signals,  originally  introduced  as  a  substitute  for 
distant  signals.  With  a  block  section  extending 
from  A  to  B  a  track  circuit  for,  say,  2,000  ft.  beyond 
B  is  arranged,  so  that  when  it  is  occupied  by  a  train 
(or  car)  Ihe  signal  at  A  will  be  held  in  the  stop 
position,  the  same  as  though  the  train  were  between 


Arrangement  of  Overlaps  for  Automatic  Block  Signals  on   a  Single   Track   Line. 


button,  to  close  the  circuit  and  energize  the  mag- 
nets of  the  bell.  If  the  wire  of  this  circuit  should 
be  broken  at  any  point,  the  closing  of  the  circuit 
at  the  button  would  fail  to  ring  the  bell,  and  the 
person  pressing  the  button  would  be  ignorant  of 
the  failure.  In  railway  signaling  such  a  condition 
would  introduce  an  element  of  danger.  See  Closed 
Circuit. 

Open  Switch.  Set  so  as  to  turn  trains  away  from  the 
main  track;  said  of  outlying  switches  when  set  for 
the  sidetrack.  At  interlockings,  where  switches  are 
constantly  under  the  charge  of  an  attendant,  the 
term  is  inappropriate,  as  all  such  switches  are  suit- 
ably safeguarded  by  signals;  but  it  is  used  "'every- 
where to  describe  a  derailing  switch  which  is  set  to 
turn  trains  off  the  track. 

Operated  Unit.  In  interlocking  this  term  is  used  whe;i 
speaking  collectively  of  switches,  signals,  movable 
frogs,  derails  and  any  other  apparatus  worked  or 
controlled  by  levers  in  the  machine.  For  example, 
a  machine  from  which  are  worked  10  switches,  5 
locks  and  10  signals  is  said  to  control  25  units. 
The  American  Railway  Engineering  Association 


A  and  B.  Thus,  when  signal  A  is  Cleared,  a  train 
passing  it  is  not  only  assured  of  a  clear  track  to  B, 
but  also  is  assured  that  signal  B  may  be  overrun 
2,000  ft.  without  danger  of  collision  with  the  pre- 
ceding train.  Where  a  line  is  fully  equipped  with 
distant  signals,  so  that  enginemen  will  never  need 
to  slacken  speed  to  make  sure  of  the  indication  of 
the  home  signal  before  passing  it,  the  overlap  is 
generally  deemed  unnecessary,  and  it  is  used  with 
distant  signals  only  on  a  few  lines — the  New  York 
Central  electrified  lines  and  the  Interborough 
(New  York)  subway  express  tracks  being  the  most 
prominent.  Both  in  these  situations  and  where 
used  without  a  distant  signal,  and  as  a  substitute 
for  it,  the  overlap  is  criticised  because  it  tends  to 
impair  discipline,  its  presence  suggesting  that  a 
signal  indicating  "stop"  (at  that  signal)  need  not 
be  strictly  obeyed.  In  the  New  York  subway 
(Interborough)  and  on  the  electrified  lines  of  the 
New  York  Central,  where  overlaps  and  distant  sig- 
nals are  both  used,  the  overlaps  are  in  most  cases 
the  full  length  of  the  block  sections.  In  the  sub- 
way this  means  about  900  ft.  On  single  track  lines. 


Ove-Plu 


THE   SIGNAL  DICTIONARY 


automatic  block  signals  are  arranged  with  overlaps, 
so  as  to  prevent  the  occurrence  of  a  collision  be- 
tween trains  moving  toward  each  other,  which 
without  the  overlap  might  pass  clear  signals  at  the 
same  moment.  The  opposing  signals  are  so  situ- 
ated that  each  train  will  encounter  a  stop  signal  be- 
fore it  can  meet  the  other.  The  diagram  herewith 
shows  a  typical  arrangement  of  automatic  block 
signals  on  a  single-track  road.  Signal  B  is  con- 
trolled by  track  circuits  to  the  point  G  and  Signal 
F,  similar  to  A.  Suppose  two  approaching  trains,  to 
be  represented  by  X  and  Y.  Assume  train  Y  to 
pass  F  at  clear  at  the  same  instant  that  train  X 
passes  point  A.  Train  Y  would  set  signal  B  at 
stop  and  train  X  would  set  signal  C;  and  the  trains 
would  be  held  at  signals  C  and  B,  respectively.  If 
the  track  sections  were  arranged  so  that  train  X 
could  pass  signal  B  at  clear  and  Y  pass  F  at  clear 
at  the  same  instant,  Y  might  possibly  be  stopped 
at  C,  but  X,  having  a  clear  signal  at  B,  would  con- 
tinue on  through  the  block  and  collide  with  Y. 
In  the  positions  shown  the  two  trains  would  set 
signals  C  and  E  at  stop.  See  Figs.  312,  324,  486, 
489,  495,  498,  653,  675,  686-688. 
Overstroke.  Excess  throw  in  a  pipe  or  wire  line. 


Pan  Copper.  A  copper  element  of  peculiar  shape  used 
in  gravity  batteries.  See  Figs.  2306-2308. 

Parallel.     (Applied  to   electric  circuits.)     See  Multiple. 

Parallel  Bar.  A  British  term  for  Detector  Bar,  which 
see. 

Period.  The  interval  of  time  between  two  successive 
passages  of  a  vibration  through  a  given  point  of  its 
path  taken  in  the  same  direction.  The  time  occu- 
pied in  performing  a  complete  cycle. 

Permanent  Magnet.  A  name  sometimes  given  to  a 
magnet  composed  of  hardened  steel,  whose  mag- 
netic retentivity  is  high. 

Permissive  Block  Signaling.  Permitting  one  or  more 
trains  moving  in  the  same  direction  to  enter  a 
block  section  before  the  last  preceding  train  has 
passed  out  at  the  other  end.  In  such  cases  the  fol- 
lowing train  is  allowed  to  proceed,  expecting  to  find 
the  track  blocked,  and  prepared  to  stop  before 
reaching  any  obstruction,  without  being  warned  by 
a  flagman  or  otherwise.  Permission  to  proceed  is 
given  by  a  written  card  from  the  signalman;  or  by 
signal  indication  (the  intermediate  position  of  a 
three-position  signal)  or  by  flag  or  hand  lantern. 
In  automatic  block  signal  systems  the  practice  gen- 
erally is  permissive,  for  if  a  signal  were  out  of  order 
and  indicating  stop  the  line  would  be  blocked  until 
the  signal  could  be  repaired.  The  most  common 
rule  where  automatic  signals  are  used  is  to  stop 
at  a  signal  indicating  stop,  wait  one  minute  and 
then  proceed  through  the  block  with  speed  under 
control.  On  those  lines  of  the  New  York  subway 
which  have  automatic  block  signals,  and  in  a  few 
other  places,  trains  are  forbidden  to  pass  a  stou 
signal  without  first  sending  a  flagman  ahead.  On 
single  track  roads  with  automatic  signals  it  is  the 
rule  to  send  a  flagman  ahead.  After  waiting  long 
enough  for  him  to  go  a  safe  distance,  the  train  pro- 
ceeds at  low  speed  under  his  protection.  He  must 
be  sent  forward  at  once,  because  it  is  impossible 
to  know  whether  the  stop  indication  is  due  to  a 
failure  of  the  apparatus  or  to  the  presence  in  the 
block  of  an  opposing  train.  On  the  Cincinnati, 
New  Orleans  &  Texas  Pacific,  and  several  other 


roads,  the  passenger  trains  are  provided  with  light 
track  velocipedes,  carried  in  the  baggage  car  for 
use  in  flagging  ahead. 

With  the  manual  block  system  permissive  block- 
ing is  an  expedient  to  obviate  the  expense  of  main- 
taining short  block  sections  and  is  ordinarily  al- 
lowed only  with  freight  and  work  trains,  absolute 
blocking  being  enforced  before  and  behind  pas- 
senger trains.  See  Caution  Card.  For  common  ar- 
rangements of  permissive  block  signals  see  Figs. 
316-317.  With  controlled  manual  signals,  permis- 
sive blocking  is  usually  forbidden,  as  the  "control" 
attachments  would  be  made  useless. 
Permissive  Card.  See  Caution  Card. 
Phase.  The  fractional  part  of  a  cycle  of  an  alternating 
current  which  has  elapsed  since  the  current  last 
reached  its  maximum  positive  value. 
Pipe  Carrier.  A  grooved  roller  supported  in  suitable 
bearings.  In  a  mechanical  interlocking,  a  series  of 
pipe  carriers  is  used  to  support  a  line  of  pipe  for 
operating  a  switch  or  signal.  Where  only  one 
roller  is  used  it  is  called  a  one-way  pipe  carrier; 
two  rollers,  a  two-way  carrier,  etc.  A  small  top 
roller  is  frequently  used  to  keep  the  pipe  in  place 
in  the  grooved  roller.  See  Figs.  1205-1233,  1240, 
1242-1258,  1267-1268. 

Pipe  Carrier  Stand.  A  casting  carrying  the  grooved 
rollers  of  a  pipe  carrier  and  bolted  to  the  founda- 
tion. See  Pipe  Carrier. 

Pipe  Compensator.  A  device  for  automatically  com- 
pensating for  the  changes  in  the  length  of  a  pipe 
line  due  to  temperature  changes.  Such  a  device  is 
necessary  in  long  pipe  lines  in  order  to  preserve  a 
uniform  range  of  movement  at  the  end  connected 
to  the  switch  or  signal.  The  simplest  form  con- 
sists of  a  straight  lever  pivoted  at  the  center  and 
having  one  section  of  the  pipe  attached  to  one  end 
and  the  adjoining  section  to  the  other  end.  If  one 
or  more  compensators  are  placed  between  the  lead- 
out  and  the  outlying  end  of  the  pipe  line,  each  in 
the  middle  of  the  section  of  pipe  to  be  compen- 
sated by  it,  the  only  effect  of  changes  of  tempera- 
ture will  be  to  change  the  angle  of  the  compen- 
sating lever.  In  order  to  keep  the  pipe  in  a  straight 
line  a  form  of  self-contained  double  compensator 
called  a  Lazy  Jack,  which  see,  is  most  frequently 
used.  Where  a  line  of  pipe  changes  direction,  the 
crank  at  the  angle  can  be  arranged  to  serve  as  a 
compensator.  See  Compensator. 
Pipe  Coupling.  See  Pipe  Plug.  See  also  Figs.  1026- 

1030. 

Pipe  Line.  The  common  name  for  the  line  of  rodding 
which  connects  a  switch  or  signal  to  its  lever,  such 
rodding  being  usually  made  of  one-inch  wrought 
iron  or  steel  pipe.  In  Great  Britain  rods  of  L 
shape  are  used  extensively.  See  Fig.  1010. 
Pipe  Line  Lug.  See  Figs.  1031,  and  21,  22,  23,  26,  27,  28, 

Figs.   1047-1121. 

Pipe  Plug.  A  piece  of  round  iron  rod,  used  to  stiffen 
pipe  at  a  joint.  It  is  used  in  addition  to  the  pipe 
sleeve  and  is  riveted  to  the  pipe.  See  Figs.  1026- 
1027. 

Pipe  Run.  In  an  interlocking  plant,  an  assemblage  of 
pipe  lines,  with  their  carriers  and  foundations  in  a 
common  course.  See  Pipe  Line. 

Pit.  A  depression  below  the  floor  level  of  an  inter- 
locking tower  in  which  the  leadout  apparatus  is 
situated. 

Plunge  (verb).  In  controlled  manual  block  signaling, 
the  operation  which  is  required  to  release  the  sig- 


26 


THE   SIGNAL   DICTIONARY 


Plu-Pow 


nal    lever   at    the    distant    station.      See    Controlled 
Manual,  pages  27-45,  Figs.  346-405. 

Plunger.     The  handle  or  other  operating  device  of  the 

"lock    and    block"    instrument.      The    term    is    also 

applied  to  the   bar  which   effects  the  locking  in  a 

facing  point  lock.     See  Figs.  346-405. 

Plunger    Box.      The    casting    or    guide    in    which    the 

plunger  of  a  bridge  bolt  lock  moves. 
Plunger  Casting.     A  stand  and  guide  for  facing  point 
and  bridge  lock  plungers  and  lock  rods.     See  Figs. 
1467-1478,   1736-1738,  I747-I/49.  I753-I757- 
Plunger  Lock.     See  Facing  Point  Lock.    See  also^Figs. 

1467-1478,  1736-1/38,  1747-1749,  1753-1757- 
Plunger  Release  Track  Circuit.  That  track  circuit  by 
means  of  which  plunger  of  block  instrument  is  re- 
leased. Operates  in  conjunction  with  circuit  con- 
troller of  home  lever  and  circuit  controllers  oper- 
ated by  arms  of  distant  and  home  signals  to  effecc 
release  of  plunger  of  block  instrument  after  whole 
train  has  passed  home  signal  and  home  signal  is 
locked  in  normal  position,  home  signal  indicates 
stop  and  distant  signal  caution.  So  located  that 
train  passing  through  block  station  limits  will  not 
pass  off  plunger  release  track  until  whole  train 
has  passed  home  signal. 

Pneumatic  Interlocking.  Interlocking  apparatus  in 
which  both  the  power  to  work  the  switches  and 
signals  and  the  instrumentalities  for  controlling 
that  power  from  the  cabin  are  actuated  by  com- 
pressed air.  In  the  older  electro-pneumatic  appa- 
ratus the  switches  and  signals  are  worked  by  com- 
pressed air,  but  the  air  valves  are  controlled  from 
the  tower  electrically.  See  Figs.  1955-2040. 
Point  Lug.  A  lug  bolted  to  the  web  of  a  switch  point, 
to  which  the  switch  rods  are  attached.  See  Figs. 
1486-1512. 

Point  Rail.  In  a  "split"  switch,  either  of  the  two  mov- 
able rails,  pointed  at  the  movable  end,  as  distin- 
guished from  the  immovable  "stock"  rails. 
Point  Separator.  A  device  for  spacing  the  inner  points 
of  a  double  slip  switch  in  relation  to  each  other. 
Used  in  place  of  a  switch  point  lug,  which  see. 
Polarized  Relay.  A  direct  current  relay,  having  a  per- 
manently magnetized  ("polarized")  armature  which 
responds  to  changes  in  the  polarity  of  the  electro- 
magnet, resulting  from  changes  in  the  direction 
of  the  current  flowing  in  the  magnet  coils.  Con- 
tacts carried  by  the  polarized  armature  close  a 
local  circuit  when  the  armature  moves  to  one  posi- 
tion under  the  influence  of  current  in  one  direction 
in  the  magnet  coils  and  open  such  circuit  when 
current  Hows  in  the  opposite  direction.  See  Figs. 
700,  30/5-3077,  3079-3080,  3085-3092,  3096. 
Polarized  Track  Circuit.  See  "Wireless"  Automatic 

Block  Signal  System. 

Pole  Changer.  A  double-pole,  double-throw  switch  so 
connected  that  the  alternate  positions  effect  a 
change  in  the  direction  of  the  current  in  the  con- 
necting wires.  In  block  signaling  it  is  attached  to 
and  worked  by  the  home  signal,  for  reversing  the 
polarity  of  the  track  circuit  of  the  section  in  the 
rear,  by  changing  the  connection  from  the  battery 
to  the  line.  This  is  done  to  control  the  distant 
signal  in  the  rear,  through  the  track  circuit,  thus 
obviating  the  need  of  a  line  wire  for  such  control. 
See  Figs.  529-530;  P,  Fig.  537. 

Pole-piece.  That  part  of  the  core  of  an  electromagnet 
which  projects  beyond  the  coil  and  near  which  the 
armature  is  placed.  Often  in  the  form  of  a  block 


attached  to  the  core.    Used  to  concentrate  the  lines 
of  force. 

Polyphase.     Possessing  more  than  a  single  phase. 

Polyphase  Currents.  Currents  differing  in  phase  from 
one  another  by  a  definite  amount,  and  suitable  for 
the  operation  of  polyphase  motors  or  similar  appa- 
ratus. 

Polyphase  Relay.  A  relay  designed  to  respond  to  poly- 
phase alternating  current.  See  Figs.  656-657,  696. 

Portable  Batteries.  A  portable  battery  consists  of  one 
or  more  cells  mounted  conveniently  as  a  unit  for 
handling.  The  number  of  cells  should  be  limited 
by  the  maximum  weight  desired.  If  the  number  of 
cells  in  one  unit  is  not  sufficient  to  obtain  the  work- 
ing voltage,  additional  units  are  connected  in  series. 
The  size  of  the  cell  is  determined  as  in  stationary 
battery.  The  plates  should  be  of  minimum  weight 
consistent  with  reasonably  long  life.  They  are  as- 
sembled in  groups  and  elements,  and  mounted  (in 
a  suitable  container),  so  as  to  reduce  chance  of 
breakage  to  a  minimum.  There  should  be  no  metal 
connections  other  than  lead  exposed  in  order  to 
prevent  corrosion  from  acid.  All  metal  connections 
should  be  so  arranged  as  to  reduce  corrosion  from 
acid. 

Post.     See  Signal  Post;  Bracket  Post. 

Note. — Post,  pole,  bracket  mast,  mast. — Post,  is 
used  to  define  the  vertical  member  of  a  semaphore 
signal,  because  it  supports  something.  Pole  means 
a  slender  piece  of  timber,  implying  inability  to  sup- 
port a  load.  Bracket  mast  is  used  to  define  the 
upper  vertical  members  of  a  bracket  signal,  particu- 
larly that  one  of  those  members  which  carries  no 
arm  and  merely  aids  in  making  clear  the  position 
and  meaning  of  the  others.  Mast  is  used  in  the 
codes  of  the  American  Railway  Association  to  de- 
fine the  post  (as  in  a  bracket  post  signal),  to  which 
the  arm  is  attached,  in  distinction  from  the  single 
post,  set  in  the  ground,  supporting  two  or  more 
"masts."  See  Figs.  279-307. 

Pot  Signal.  A  low  revolving  signal,  turning  on  a  ver- 
tical axis  and  used  either  as  a  switch  target  for  in- 
dicating the  position  of  the  switch  (to  which  it  is 
attached)  or  as  a  dwarf  signal  for  low-speed  move- 
ments. Now  generally  superseded  as  a  dwarf  sig- 
nal by  the  Dwarf  Semaphore,  which  see.  It  con- 
sists of  a  lamp  having  either  two  or  four  lenses, 
two  lenses  being  used  for  dwarf  signals  and  four 
lenses  fqr  switch  targets.  The  faces  of  the  lamp, 
usually  made  as  flaring  disk,  are  painted  corre- 
sponding colors  to  the  lenses,  and  these  colors  give 
the  day  indications.  Signals  thus  turning  on  a  ver- 
tical axis  are  used  in  some  tunnels  and  yards  where 
there  is  not  room  for  a  semaphore.  See  Night  Sig- 
nal Indications.  See  Figs.  1666-1667,  1682-1683, 
1687-1691. 

Potash  Battery.  A  primary  battery  using  caustic 
potash  solution  for  the  electrolyte  and  having  cop- 
per oxide  for  the  positive  element  and  metallic 
zinc  for  the  negative  element. 

Power.  Rate-of-doing-work,  expressible  in  watts, 
joules-per-second,  foot  pounds-per-hour,  etc.  Ac- 
tivity. 

Power  Factor.  The  ratio  of  the  true  watts  to  the 
apparent  volt-amperes  in  an  alternating  current 
conductor,  circuit,  or  device.  It  equals  the  cosine 
of  the  angle  of  lag  of  the  alternating  current. 
Power  Interlocking.  Interlocking  apparatus  operated 
by  some  form  of  power  other  than  manual,  usually 
electricity  or  compressed  air  or  a  combination  of 


Pow-Rel 


THE   SIGNAL  DICTIONARY 


27 


the  two.  See  Power  Interlocking  Machine  and 
Figs.  1762-2054. 

Power  Interlocking  Machine.  An  Interlocking  Ma- 
chine, which  see,  in  which  the  levers  for  moving 
switches  and  signals  by  manual  power  are  sup- 
planted by  levers,  or  sliding  bars,  for  convenience, 
called  levers,  which  merely  close  or  open  electric 
circuits,  or  in  the  all-air  machine  open  or  close  air- 
valves.  In  the  "electric"  system  the  electric  power 
moves  the  switches  and  signals.  In  the  electro- 
pneumatic  compressed  air  moves  the  switches  and 
signals,  and  the  air  valves  are  worked  by  electro- 
magnets controlled  from  the  interlocking  machine. 
See  Figs.  1762-2054. 

Preliminary  Locking.  Interlocking  so  arranged  that 
the  locking  of  a  lever,  to  prevent  it  from  being 
moved  in  conflict  with  another,  which  is  about  to 
be  moved,  is  fully  effected  before  that  other  lever 
begins  to  perform  its  function.  In  mechanical  in- 
terlocking this  is  Latch  Locking,  which  see.  In 
power  machines  the  "levers"  are  so  arranged  that 
the  lever  by  a  single  stroke  does  three  things:  In 
its  first  part  the  locking  of  conflicting  levers;  in  its 
second  the  performance  of  its  own  main  function 
(causing  the  movement  of  a  switch  or  signal),  and 
in  its  third  the  unlocking  of  other  levers  which 
then  may  properly  be  moved. 

Primary.  That  winding  of  an  induction  motor  or  of 
a  transformer  which  directly  receives  power.  The 
term  is  to  be  preceded,  in  the  case  of  transformers, 
by  the  words  "high  voltage"  or  "low  voltage,"  in 
the  case  of  induction  motors  by  "rotating"  or  "sta- 
tionary." 

Primary  Battery.  More  properly  primary  cell.  Any 
combination  of  two  metals  or  metalloids,  which 
when  immersed  in  a  liquid  termed  an  electrolyte, 
and  connected  outside  the  liquid  by  a  conductor, 
will  produce  a  current  of  electricity.  A  large  num- 
ber of  such  cells  employing  different  elements  and 
electrolytes  are  in  use.  The  action  in  a  primary 
cell  is  electro-chemical,  the  electrolyte  being  de- 
composed by  the  passage  of  the  current  and  at- 
tacking one  or  both  of  the  elements.  In  the  cell 
the  current  flows  from  the  metal  most  acted  on  to 
the  metal  least  acted  on.  In  a  zinc  and  copper 
cell  with  dilute  sulphuric  acid  as  the  electrolyte, 
for  example,  the  current  flows  through  the  liquid 
from  the  zinc  to  the  copper.  In  the  external  cir- 
cuit the  direction  is,  of  course,  the  opposite  and 
the  zinc  electrode  is  negative,  while  the  copper 
electrode  is  positive.  The  most  usual  combinations 
of  elements  are  (i)  zinc  and  carbon  and  (2)  zinc 
and  copper.  See  Storage  Battery;  Gravity  Cell. 
See  Figs.  2297-2351. 

Pulling  Wire.  The  wire  attached  to  the  front  tail 
lever  of  an  interlocking  machine  which  pulls  a 
signal  clear.  See  Back  Wire. 

Push  Button.  A  device  for  closing  an  electric  circuit 
by  the  movement  of  a  button. 

Pusher.  A  locomotive  used  to  push  a  train  up  an  as- 
cending grade,  usually  co-operating  with  another 
engine  attached  in  the  regular  way  to  the  front  of 
the  train.  The  pusher  is  detached  at  the  top  of  the 
grade;  and  as  that  point  may  be  between  block 
stations  special  block  signal  arrangements  are 
sometimes  prescribed  to  permit  the  pusher  to  back 
down  on  the  same  track  to  the  point  from  which 
it  began  the  ascent.  See  Electric  Train  Staff  Sys- 
tem. 


Pusher  Attachment.  An  attachment  to  electric  train- 
staff  apparatus,  designed  to  protect,  in  addition  to 
the  regular  train  movement,  the  movement  of  a 
pushing  engine  when,  after  being  detached  from 
the  rear  of  the  train,  it  is  to  be  run  back  to  its 
starting  point.  See  Electric  Train  Staff  System, 
also  see  pages  27-45. 

R 

Radial  Arm.     See  Figs.  1185-1204. 

Rail.  The  continuous  line  of  rails  constituting  one 
side  of  a  track.  Contiguous  rails  are  spoken  of 
collectively  as  the  left  hand  or  right  hand  rail  of 
the  track. 

Rail  Bond.  A  wire,  or  wires,  about  two  feet  long,  used 
to  connect  the  adjacent  ends  of  contiguous  rails, 
in  a  track,  to  insure  the  continuity  of  that  line  of 
rails  as  an  electrical  conductor.  Thus,  in  a  track 
circuit  of,  say,  one  mile  in  length,  each  of  the  two 
lines  of  rails  constituting  that  track  is  a  conductor 
one  mile  long.  In  a  new  track  the  bars  and  bolts 
fastening  two  rails  together  may  serve  as  an  elec- 
trical bond,  but  they  are  not  to  be  depended  on. 
See  Figs.  3594-3627. 

Rail  Brace.  An  iron  block  or  frame,  against  which  the 
web  of  the  rail  may  rest.  Used  to  take  side  thrust 
at  switches  and  thereby  maintain  the  gage  of  the 
track.  Usually  held  in  place  on  the  tie  plate  by 
lag  screws  or  spikes  and  a  butt  strap  or  projection 
on  the  plate.  See  Figs.  1485,  1529-1530. 

Rail  Clip.  A  metal  support  bolted  or  clamped  to  a  rail 
for  carrying  a  detector  bar  through  suitable  con- 
nections. See  Figs.  1568-1611. 

Railway,  Electric.     See  Electric  Railway. 

Ramp.  In  cab  signaling  or  train  stopping  systems,  a 
bar  with  an  inclined  upper  surface  fixed  on  the 
ties  of  the  track  and  designed  to  lift  a  verti- 
cally moving  member  depending  from  a  passing 
locomotive.  For  example,  a  ramp  might  be  fifty 
feet  long,  with  its  near  end  about  three  inches 
lower  than  its  far  end.  Thus  the  lifting  will  be 
effected  at  moderate  speed,  avoiding  shocks,  even 
if  the  speed  of  the  engine  is  high. 

Reactance.  In  an  alternating  current  circuit  the  com- 
ponent of  impedence,  or  total  effect  retarding  the 
flow  of  current,  which  is  out  of  phase  with  or  90 
deg.  from  the  phase  of  the  current.  The  ohmic 
effect  due  to  the  induction  in  the  circuit.  See 
Resistance  and  Impedance. 

Reactance  Bond.     See  Inductive  Bond. 

Reactance  Coil.  A  coil  for  producing  difference  of 
phase  or  for  eliminating  current.  A  magnetizing 
coil  surrounded  by  a  conducting  covering  or  sheath- 
ing which  opposes  the  passage  of  rapidly  alternat- 
ing currents  less  when  directly  over  the  magnetiz- 
ing coil  than  when  a  short  distance  from  it.  A 
choking  coil  or  reactor. 

Rear.  As  used  to  define  signals,  one  which  is  back  of 
another,  as  related  to  the  train  for  which  such 
signal  is  used.  A  distant  signal  is  in  the  rear  of 
(not  in  advance  of)  a  home  signal. 

Rear  Collision.  A  collision  in  which  a  train  (or  en- 
gine) collides  with  a  train,  car,  or  engine  ahead  of 
it,  headed  in  the  same  direction  as  itself. 

Rectifier.     See  Mercury  Arc  Rectifier. 

Relay.  In  its  most  common  form,  an  electromagnet 
designed  to  repeat  the  effects  of  an  electric  current 
in  a  second  circuit.  For  example,  in  a  telegraph 
line,  the  relay  is  energized  by  the  comparatively 


28 


Rel-Sel 


weak  current  of  the  line,  and  its  armature,  being 
thereby  attracted,  by  suitable  contacts  mounted  on 
it,  closes  the  strong  local  circuit.  In  a  track  circuit, 
the  relay,  delicately  adjusted  to  close  its  armature 
on  the  passage  of  the  weak  current  of  the  track  cir- 
cuit, closes  the  strong  local  circuit  which  works  or 
controls  the  signal.  A  relay  having  an  armature 
bearing  a  number  of  contacts  can  be  made  to  close 
as  many  different  local  circuits.  When  the  arma- 
ture of  a  relay  is  attracted,  it  closes  a  front  contact; 
when  the  coils  of  the  magnet  are  de-energized 
and  the  armature  falls  away  by  gravity  or  is  drawn 
away  by  a  spring,  it  closes  a  back  contact.  See 
Figs.  3044-3103.  See  Interlocking  Relay,  Neutral 
Relay,  Mercury  Contact  Relay.  For  other  kinds 
of  relays  see  Alternating  Current  Relay,  Frequency 
Relay,  Polarized  Relay,  Polyphase  Relay,  Vane  Re- 
lay. 
Relay  Post.  A  post  set  in  the  ground  to  support  a 

relay  box. 

Repeater.    See  Signal  Repeater. 

Repulsion  Motor.  An  electric  motor  deriving  its  power 
from  the  repulsion  between  electric  charges.  An 
alternating  current  motor  deriving  its  power  from 
the  repulsion  between  electric  currents.  An  alter- 
nating current  motor  in  which  the  armature  is  pro- 
vided with  temporarily  short-circuited  windings  by 
means  of  a  commutator  and  brushes. 
Residual  Magnetism.  The  magnetism  remaining  in  a 
core  of  an  electromagnet  on  the  opening  of  the 
magnetizing  circuit.  The  small  amount  of  magnet- 
ism retained  by  soft  iron  when  removed  from  any 
magnetic  flux. 

Resistance.  That  which  opposes  or  retards  the  pas- 
sage of  an  electric  current.  In  a  direct  current 
circuit  the  resistance,  according  to  Ohm's  Law,  is 
the  ratio  of  the  electromotive  force  which  causes 
the  current  to  flow  and  the  current  so  produced. 

E 
R  =  — .     In  an  alternating  current  circuit  resistance 

I 

is  the  component  of  impedance  or  total  retarding 
effect  which  is  in  phase  with  or  parallel  to  the  cur- 
rent. The  unit  of  measurement  of  resistance  is  the 
Ohm,  which  see.  The  following  table  gives  the 
relative  resistance  of  several  of  the  most  widely 
used  metals  and  of  carbon,  as  compared  with  sil- 
ver, the  best  conductor  known: 

Silver    i.oo 

Copper     1.063 

Gold    1.369 

Aluminum   1-935 

Zinc    3.741 

Platinum    6.022 

Iron    6.460 

Lead   13.05 

German   Silver    13.920 

Mercury 62.73 

Graphite    750.00 

Coke  Carbon   6250.00 

Resistance  Grid.  See  Resistance.  Figs.  678-679. 
Reverse  (verb).  To  reverse  a  mechanical  signal  lever 
is  to  move  it  from  its  normal  to  the  opposite  posi- 
tion. In  the  electro-pneumatic  machine  signal  lev- 
ers have  three  positions.  The  central  position  is 
normal  and  the  lever  is  moved  to  the  right  to 
control  one  signal  and  to  the  left  to  control  an- 
other. 

Rheostat.     An  adjustable  resistance.     See  Figs.  678-670. 
Riser   Plate.     An   iron   plate   riveted   to   the   Tie  Plate, 


which  see,  at  a  switch  and  used  to  support  the 
switch  points.  Sometimes  called  a  slide  plate. 

Rocker  Shaft.     See  Figs.  1010-1015,  1279-1292. 

Rocker  Shaft  Leadout.     See  Figs.  1010-1015. 

Rotary  Converter.  A  secondary  generator  for  trans- 
forming alternating  into  continuous  currents  or 
vice  versa,  consisting  of  an  alternating  current  ma- 
chine whose  armature  winding  is  connected  with  a 
commutator. 

Rotor.  The  rotating  member,  whether  primary  or  sec- 
ondary, of  any  alternating  current  machine. 

Roundel.  A  round,  flat  piece  of  glass,  as  the  coIore-,1 
glasses  used  in  semaphore  signals. 

Route.  A  course  or  way  taken  by  a  train  in  passing 
from  one  point  to  another,  especially  a  customary 
or  predetermined  course,  as  in  a  yard;  or  any  one 
of  several  possible  combinations  of  turnouts  or 
crossovers  by  which  a  train  may  travel  from  one 
place  to  another. 

Route  Locking.  The  electric  locking  of  switches  draw- 
bridges, etc.,  in  a  route,  or  the  signals  of  a  con- 
flicting route,  to  maintain  the  integrity  of  a  route 
during  the  movement  of  a  train  over  that  route. 
Route  locking  may  take  effect  upon  the  clearing 
of  the  signal  governing  the  route  and  maintain 
the  integrity  of  the  route  from  that  time  until  a 
train  has  passed  over  the  route.  See  Electric  Lock- 
ing, Track  Circuit  Locking.  See  Figs.  2055-2088. 


S.  L.  M.    Abbreviation  for  Switch  and  Lock  Movement. 

S  Armature.     See  Z  Armature. 

Saxby  &  Farmer  Interlocking  Machine.  The  most 
common  form  of  mechanical  interlocking  machine 
in  use  in  America.  See  F~igs.  790-850. 

Schedule.     See  Time  Table. 

Scotchblock.  A  block  of  wood  or  metal  to  be  fastened 
on  one  or  both  rails  of  a  track,  as  at  the  outlet  of 
a  siding  or  turnout,  designed  to  throw  off,  the 
track  any  car  accidentally  running  from  the  siding 
to  the  main  track  when  unattended  or  at  a  time 
when  such  a  movement  would  possibly  lead  to  a 
collision.  See  Derail. 

Screw  Jaw.  A  jaw  fastened  by  a  screw  so  as  to  be  ad- 
justable. See  Figs.  1047-1133. 

Screw  Release.  A  device  for  releasing  an  electric  lock 
(in  a  mechanical  interlocking  machine)  which,  be- 
cause out  of  order,  or  by  reason  of  some  other 
abnormal  condition,  such  as  an  error  on  the  part 
of  a  signalman,  holds  locked  a  lever  which  it  is 
desirable  to  move  in  order  to  avoid  delaying  a 
train.  To  prevent  hasty  action  by  a  disturbed  or 
excited  signalman,  the  release  is  so  made  that  it 
can  be  operated  only  by  turning  a  screw  a  certain 
predetermined  number  of  times.  The  release  must 
always  be  restored  to  its  original  condition  before 
normal  operation  of  the  interlocking  machine  can 
be  accomplished.  Sec  Figs.  2831-2859. 

Secondary.  That  portion  of  an  induction  motor  or  of 
a  transformer  which  receives  power  by  induction. 
The  term  is  to  be  preceded  by  the  same  words  as 
in  the  case  of  "primary." 

Secondary  Battery.     See  Storage  Battery. 

Selective  Dispatching  or  Signal  System.  A  system  in 
which  a  number  of  audible  or  visible  signals  lo- 
cated along  a  railway  line  are  connected  to  a  tele- 
phone, telegraph  or  other  circuit,  and  in  which  any 
one  of  such  signals  may  be  operated  by  means  of 
an  electric  selector  without  interfering  with  other 
signals  associated  with  such  circuit.  The  operation 


Sei-Sig 


THE   SIGNAL  DICTIONARY 


29 


of  the  selectors  is  controlled  by  the  train  dispatcher 
or  other  official  in  charge  of  the  system,  located 
at  any  point  along  the  line.  The  operation  of  the 
selectors  does  not  interfere  with  simultaneous  tele- 
phone or  telegraph  service  over  the  circuit.  The 
use  of  this  system  has  been  principally  confined 
to  electric  lines.  See  Figs.  714-739. 

Selector.  A  device  whereby  the  position  of  one  or 
more  functions  determines  which  of  several  others 
shall  be''0perated.  For  example,  a  single  mechan- 
ical lever,  arranged  to  clear  two  different  signals, 
works  a  pipe  line  which  engages  a  connection  to 
one  or  the  other  of  those  signals  according  as  a 
switch  is  in  one  or  the  other  of  its  two  positions. 
This  economizes  levers.  See  Electric  Selector. 
See  Figs.  1021,  1025. 

Self-induction.  Induction  produced  in  a  circuit  by  the 
induction  of  the  current  on  itself  at  the  moment  of 
starting  or  stopping  the  current  therein. 

Semaphore  Bearing.  The  bearing  which  supports  the 
semaphore  casting.  See  Figs.  3331-3333,  3352-3356, 
33/8-3395,  3465-3468. 

Semaphore  Casting.  A  casting  comprising  the  Arm 
Casting  and  Spectacle  of  a  semaphore  signal.  See 
Figs.  3312-3313,  3329-3.330,  3370-3377,  3397-3400,  3402- 
3415,  3423-3427,  3437-3438,  3472-3476. 

Semaphore  Shaft.  The  shaft  which  carries  the  sema- 
phore casting. 

Semaphore  Signal.  A  type  of  signal  introduced  on 
railways  in  England  about  1841  and  now  in  almost 
universal  use  for  both  block  and  interlocking  sig- 
nals. It  consists  of  an  arm  about  four  feet  long 
and  ten  inches  wide,  mounted  on  a  post  usually 
twenty-four  feet  to  thirty  feet  high  at  one  side  of 
the  tracks;  or  on  a  shorter  post  supported  by  a 
bridge  or  other  structure  above  the  track.  Day 
indications  are  given  by  the  position  of  the  arm, 
horizontal,  inclined  or  vertical,  and  night  indica- 
tions by  a  light.  The  pivot  of  the  arm  is  combined 
with  a  spectacle  casting  holding  colored  glass  disks, 
which,  as  the  position  of  the  arm  is  changed,  move 
in  front  of  a  lamp  mounted  on  the  post.  See  Night 
Signal  Indications.  See  Figs.  1-33,  229-241,  250- 
324,  3224-3305,  3319-3327,  3436-3438,  3444-3447- 

Semi-automatic  Signal.  A  signal  having  both  manual 
and  track  circuit  control.  Such  a  signal  can  be 
cleared  by  the  signalman  only  when  the  track  cir- 
cuit is  unoccupied;  but  it  may  be  put  in  the  "stop" 
position  either  manually  or  by  the  entrance  of  a 
train  upon  the  circuit.  See  Electric  Slot.  See  Figs. 
3479-3492. 

Separate  Pin  Leadout  Crank.  See  Box  Crank.  See 
Figs.  1156-1160. 

Series  (applied  to  electric  circuits).  Two  or  more 
pieces  of  electrical  apparatus,  such  as  lamps  or 
motors,  are  said  to  be  connected  in  series  when 
all  the  current  from  a  common  source  of  supply 
flows  from  the  supply  through  one  piece  of  appa- 
ratus, thence  to  the  next  and  so  on  to  a  return 
wire  leading  back  to  the  supply.  See  Multiple. 

Series  Circuit.  A  circuit  in  which  the  separate  sources 
or  separate  electro-receptive  devices,  or  both,  are 
so  placed  that  the  current  produced  in  it  or  passed 
through  it  passes  successively  through  the  entire 
circuit  from  the  first  to  the  last. 

Shackle.     See  Fig's.  1293-1304. 

Shell  Transformer.  A  transformer  whose  primary  and 
secondary  coils  are  laid  on  each  other,  and  the 


iron  core  is  then  wound  through  and  over  them,  so 
as  to  completely  enclose  them.  A  form  of  iron- 
clad transformer. 

Shim.  A  thin  piece  of  wood  or  metal  to  be  put  under 
the  rail  of  a  track,  on  the  tie,  to  compensate  for 
irregularities  in  surface.  In  severe  and  long  con- 
tinued cold  weather  the  ties  in  a  piece  of  track  may 
become  considerably  displaced  vertically  by  the 
action  of  frost  in  the  ground.  It  may  elevate  ties 
a,  b,  d,  e,  g,  i,  2,  or  more  inches,  leaving  ties  c,  f 
in  their  original  positions.  Shims  must  be  put  on 
these  two  ties  to  give  adequate  support  to  the  rail. 

Short  Circuit.  A  shunt  or  by-path  of  negligible  or  com- 
paratively small  resistance,  placed  around  any  part 
of  an  electric  circuit  through  which  so  much  of  the 
current  passes  as  to  virtually  cut  out  the  parts  of 
the  circuit  to  which  it  acts  as  a  shunt.  An  acci- 
dental direct  connection  between  the  mains  or  main 
terminals  of  a  dynamo  or  system  producing  a 
heavy  overload  of  current.  To  accidentally  pro- 
duce a  short  circuit. 

Shunt  (verb).  Literally,  to  turn  aside.  To  divert  a 
part  of  an  electric  current  by  establishing  for  it  an 
additional  path. 

Shunt  Circuit.  A  derived  circuit.  A  branch  or  addi- 
tional circuit,  provided  in  any  part  of  a  circuit, 
through  which  the  current  branches  or  divides,  part 
flowing  in  the  original  circuit  and  part  through  the 
new  branch  or  shunt.  A  circuit  for  diverting  or 
shunting  a  portion  of  the  current. 

Signal.  A  sign,  agreed  upon,  to  convey  information, 
especially  at  a  distance.  Specifically,  in  railway 
train-operating,  a  means  of  conveying  information 
to  the  person  or  persons  in  immediate  charge  of 
the  movement  of  a  train.  See  the  adjectives  Home, 
Distant,  Disk,  etc.  Note. — This  book  is  devoted  to 
fixed  signals,  as  distinguished  from  hand-motion 
signals,  etc. 

Signal  Box  (British).     A  Signal  Cabin,  which  see. 

Signal  Bracket.  A  column  or  post  with  offset  support 
(or  supports)  for  signal  masts. 

Signal  Bridge.  A  bridge,  the  purpose  of  which  is  to 
support  signals  above  the  tracks.  The  signal  post 
or  disk  is  mounted  on  the  bridge.  Used  most  fre- 
quently in  yards  where  there  is  not  sufficient  clear- 
ance to  place  a  post  between  tracks.  See  Figs. 
3444-3447- 

Signal  Cabin.     See  Tower. 

Signalman.  The  attendant  at  a  block  or  interlocking 
signal  cabin.  Often  he  has  the  triple  function  of 
signalman,  switchman  and  telegraph  operator,  but 
with  only  this  one  title. 

Signal  Mast.  The  upright  to  which  the  signals  are  di- 
rectly attached. 

Signal  Mechanism.  A  term  used  to  denote  the  appa- 
ratus at,  or  within  the  case  of,  or  placed  upon  the 
post  of,  a  power-operated  signal  which  directly  op- 
erates the  semaphore  arm  or  disk  of  the  signal. 
See  Figs.  512-602,  606,  615,  620,  621,  623,  624,  627, 
644,  659,  660,  662,  664,  665,  693-695,  699,  702-703,  705. 
706,  709,  711,  732,  733,  1814-1819,  1832-1840,  1885- 
1888,  1908-1919,  1924-1927,  1946-1951,  1980-1981,  1983- 
1988,  1995-1997,  2025,  2035-2040. 

Signal  Post.  The  upright  and  supporting  member  of  a 
semaphore  signal.  It  may  be  of  wood  about  eighr 
inches  square,  or  of  iron,  built  up,  or  of  iron,  tubu- 
lar (Figs.  1639-1646). 


THE   SIGNAL  DICTIONARY 


Sig-Sta 


Signal  Repeater.  An  indicator  which  shows  in  a  tower 
the  changes  in  position  of  the  arm  or  movable 
disk  of  a  fixed  signal.  See  Fig.  2604. 

Signal  Tower.     See  Tower. 

Single  Phase.  Uniphase.  Monophase.  Pertaining  to 
ordinary  alternating  currents  in  simple  alternating 
current  system  as  distinguished  from  multiphase 
currents. 

Single-pole  Switch.  A  switch  which  opens  or  closes  a 
circuit  at  one  of  its  leads  only. 

Single-throw  Switch.  A  switch  having  but  two  posi- 
tions, one  for  opening,  and  the  other  for  closiqg  the 
circuit  it  controls,  as  distinguished  from  a  double- 
throw  switch. 

Slide  Plate.     See  Riser  Plate. 

Slot.  A  disconnecting  device  inserted  in  the  connection 
between  a  signal  arm  and  its  operating  mechanism. 
See  Electric  Slot.  In  its  original  English  form 
the  "slot"  consists  of  rods  having  cut  in  them 
long  slots.  The  slot  is  used  to  put  a  signal  in  the 
stop  position,  regardless  of  the  action  or  inaction 
of  the  signalman  in  charge  of  such  signal.  With 
the  slot  arrangement  a  given  signal  can  be  put  in 
the  stop  position  by  either  of  two  signalmen,  but 
it  cannot  be  put  in  the  clear  position  except  by 
the  co-operation  of  both  signalmen.  See  Figs. 
1734-1735,  3479-3492. 

Slotted  Signal.  A  signal  in  which  the  connection  from 
the  lever  or  other  operating  mechanism  is  con- 
trolled by  a  mechanical  or  electric  slot. 
Slow-acting  Relay.  A  relay,  the  magnets  of  which  arc 
so  designed  that  they  retain  their  magnetism  for 
an  appreciable  time  after  the  circuit  is  interrupted, 
thus  delaying  the  breaking  of  the  circuit  controlled 
by  the  relay  armature. 

Slow  Board.  A  sign,  usually  fixed  at  the  side  of  a 
railway,  on  a  board  about  thirty  inches  wide  and 
twenty  inches  high,  supported  on  a  post  from  four, 
feet  to  six  feet  high,  bearing  the  word  slow,  or  a 
legend  indicating  speed  in  miles  per  hour,  to  warn 
the  enginemen  of  trains  to  reduce  speed  at  that 
point.  The  rate  of  speed,  if  not  shown,  is  gov- 
erned by  explicit  instructions  which  are  to  be  found 
in  the  time-table  rules,  and  which  are  familiar  to 
all  of  the  enginemen  running  on  the  line. 
Slow  Releasing  Slot.  An  electric  slot  for  an  automatic 
.signal  having  a  magnet  so  made  as  to  consume  an 
appreciable  interval  of  time  between  the  breaking 
of  the  circuit  and  releasing.  Used  instead  of  and 
made  on  the  same  principles  as.  a  Slow-acting  Re- 
lay, which  see. 

Smash  Signal.  A  signal  of  special  form  used  at  the 
approach  to  particularly  dangerous  points,  such  as 
drawbridges.  Usually  some  form  of  obstruction, 
such  as  a  long  semaphore  arm  or  a  large  disk,  so 
arranged  that  when  in  the  stop  position,  it  fouls 
with  the  window  of  the  locomotive  cab.  Where  a 
disk  is  used  it  is  commonly  a  plank  frame  sus- 
pended from  a  bridge  over  the  track,  and  it  is  low- 
ered so  as  to  foul  with  the  smoke-stack.  If  a 
train  runs  past  the  signal  while  it  is  in  the  stop 
position  the  "smash"  will  call  the  engineman's  at- 
tention and  also  will  leave  a  mark  on  the  engine  or 
train.  The  signal  also  will  be  broken,  thus  afford- 
ing a  double  check  on  the  observance  of  the  signal. 
Snap  Switch.  A  switch  in  which  the  transfer  of  the 
contact'  points  from  one  position  to  another  is  ac- 
complished by  a  quick  motion  obtained  by  the 
operation  of  a  spring. 


Soldering  Flux.  Any  chemical  suitable  for  use  in  con- 
nection with  solder  to  cleanse  the  surfaces  of  the 
articles  to  be  soldered. 

Sole  Plate.     See  Insulated  Rail  Joint. 

Solenoid.  A  cylindrical  coil  of  wire;  a  helix.  Some- 
times used  in  place  of  an  electromagnet.  When 
so  used  an  iron  core  is  provided  which  enters  the 
solenoid  and  is  drawn  in  by  magnetic  attraction, 
thus  performing  the  same  function  as  the  armature 
of  an  electromagnet. 

Solenoid  Signal.    See  Solenoid.    See  Figs.  710-712,  1830- 

1833,   1836-1840. 

Space  Interval  System.  The  block  system,  as  distin- 
guished from  the  time  interval  system  of  regulat- 
ing the  movement  of  trains  following  one  another. 
Time  intervals  can  be  maintained  only  at  stations, 
and  trains  delayed  between  stations  must  be  pro- 
tected by  sending  a  man  back  along  the  road  with 
hand  signals.  As  an  auxiliary  to  this  protection 
by  flagman,  fusees  are  thrown  off  from  the  rear  of 
moving  trains.  See  Time  Interval  System. 
Spark  Gap.  The  air-space  or  gap  through  which  a  dis- 
ruptive discharge  passes.  A  gap  forming  part  of 
a  circuit  between  two  opposing'  conductors  and 
filled  with  air  or  other  dielectric,  across  which  a 
spark  passes  when  a  certain  difference  of  potential 
has  been  reached. 
Spectacle.  The  casting  which  holds  the  colored  glass 

of  a  semaphore  signal.     See  Semaphore  Casting. 
Speed  Control.     Control  of  an  automatic  train-stopping 
apparatus    by    a    means    which    is    operative    or    in- 
operative,  according  to   whether  the   speed   of   the 
train    is  or   is   not  above  a  certain    rate.      For   ex- 
ample, a  stopping  device  may  be  arranged  to  be- 
come  inoperative  whenever  the  train  is  moving  at 
a  rate  less  than  five  miles  an  hour. 
Spindle  Slot.     An  Electro-mechanical  Slot,  which   see. 
It  is  attached  to  the  semaphore  shaft  of  a  signal. 
See  Figs.  3488-3492. 
Split  Link.     See  Figs.  1293-1304. 

Split  Phase.  A  term  applied  to  an  a.  c.  motor,  relay 
or  other  similar  apparatus  that  depends  for  its  op- 
eration on  a  phase  difference  in  its  coils,  but  is  op- 
erated by  a  single-phase  current.  The  phase  differ- 
ence is  obtained  by  "splitting"  the  phase  of  the  cir- 
cuit by  an  impedance  coil  or  oil%cr  similar  device. 
Squirrel  Cage  Armature.  A  term  applied  to  a  special 
form  of  rotor  of  an  a.  c.  motor,  consisting  of  an 
iron  core,  within  the  periphery  of  which  are  em- 
bedded a  number  of  insulated  copper  conductors 
lying  parallel  to  the  axis  of  the  core,  their  ends 
being  united  usually  by  copper  rings  or  disks,  so 
that  they  form  closed  circuits. 

Staff.  That  part  of  the  apparatus  used  in  the  staff  sys- 
tem which  is  delivered  to  the  engineman  as  his 
authority  for  the  use  of  the  block. 

Staff  Crane.  With  the  electric  train  staff  system,  a 
post  with  suitable  bars  to  support  a  staff,  fixed 
near  the  track  to  enable  the  engineman  of  a  train, 
passing  at  moderate  speed,  to  reach  and  take  a 
staff.  Staff  cranes  are  also  made  to  receive  a  staff 
from  a  moving  engine.  With  suitable  apparatus 
on  the  engine  staffs  may  be  exchanged  at  high 
speed. 

Standard  Code.  The  code  of  rules  issued  by  the  Amer- 
ican Railway  Association.  It  includes  Train  Rules, 
Block  Signal  Rules  and  Interlocking  Rules.  As  is- 
sued by  the  Association,  each  of  these  three  codes 
contains  numerous  paragraphs  with  words  or 


Sta-Sto 


clauses  omitted,  the  blanks  being  designed  to  be 
filled  up,  by  individual  companies,  to  suit  the  prac- 
tice on  their  respective  roads.  "Train  rules"  cover 
the  principal  features  of  the  work  of  the  men  who 
operate  the  trains,  including  train  despatchers  and 
telegraph  operators,  and  also  station  agents,  track 
foremen  and  others,  so  far  as  their  duties  have  to 
do  directly  with  the  movement  of  trains.  This  part 
of  the  code  was  first  adopted  in  1887,  when  few 
American  railways  had  either  block  signals  or  in- 
terlocking, and  many  of  its  rules  which  under  that 
condition  are  of  vital  importance,  become  second- 
ary or  useless  when  the  block  system  is  used.  As 
used  by  the  railways  the  "train  rules"  are  supple- 
mented by  other  train  rules,  usually  more  volumin- 
ous, dealing  with  the  other  and  less  important 
duties  of  trainmen. 

Standard  Interlocking  Machine.  An  interlocking  ma- 
chine having  vertical  locking  arranged  in  a  frame 
below  the  surface  of  the  floor.  Locking  can  be 
arranged  in  two  planes  called  Front  Locking,  which 
see,  and  Back  Locking,  which  see.  Originally  made 
by  The  Standard  Railroad  Signal  Company.  Some- 
times called  "Style  A"  interlocking  machine.  See 
Figs.  851-902. 

Starting  Signal.  In  Great  Britain  a  common  arrange- 
ment of  signals  at  block  stations  is  to  have  three 
stop  signals  in  succession  called,  respectively,  the 
home,  the  starting  and  the  advanced  starting  sig- 
nals spaced  far  enough  apart  to  allow  an  ordinary 
train  to  stand  between  the  first  and  second  and 
between  the  second  and  third.  In  America  the  term 
starting  signal  has  little  recognition,  officially,  but 
it  is  used  to  designate  the  signals  at  the  outer  end 
of  a  terminal  train  shed,  or  at  the  outgoing  end  of 
a  side  track. 

Static  Transformer.  See  Transformer. 
Stationary  Battery.  A  complete  battery  consists  of 
one  or  more  cells  performing  common  work  at 
any  given  point;  the  number  of  cells  is  determined 
by  the  voltage  required  on  working  circuit,  and  the 
number  of  plates  and  size  of  plates  in  each  cell 
determined  by  the  capacity  in  ampere  hours  re- 
quired between  charges  plus  factor  of  safety. 

One  complete  cell  consists  of  positive  and  nega- 
tive plates  in  electrolyte,  contained  in  a  glass  jar 
or  tank,  provided  with  suitable  separators,  con- 
nectors and  covers.  A  two-plate  cell  is  usually 
termed  a  "couple"  and  consists  of  a  jar  containing 
a  positive  and  a  negative  plate  and  electrolyte;  each 
positive  plate  is  burned  to  the  negative  plate  in  the 
adjacent  cell. 

The  number  of  positive  plates  is  usually  one  less 
than  the  negatives  except  in  two-plate  ceils,  where 
one  positive  and  one  negative  are  used.  The  posi- 
tive plate  is  usually  brown  in  oolor  and  the  negative 
gray. 

All  the  positive  plates  in  one  cell  are  connected 
solidly  to  a  lead  strap,  and  this  combination  of 
positive  plates  and  straps  is  technically  known  as  a 
"positive  group." 

Similarly  the  negative  plates  in  one  cell  are  con- 
nected together  and  the  combination  known  as  a 
"negative  group." 

A  cell,  therefore,  contains  a  positive  group  and 
a  negative  group  assembled  with  positive  and  nega- 
tive  plates  alternately  side  by  side  and  separators 
between  plates.  This  combination  of  positive  and 
negative  groups  with  separators  is  known  tech- 
nically as  an  "element." 


One  bolt  connector  is  required  for  each  cell,  when 
assembled  end  to  end,  with  an  extra  connector  for 
each  row  of  cells.  Two-bolt  connectors  are  re- 
quired for  each  cell,  when  assembled  side  by  side, 
with  connecting  strap  between  cells.  Two-plate 
cells  or  a  "couple"  require  only  two  connectors  for 
each  row,  as  the  positive  and  negative  plates  of 
adjacent  cells  are  burned  solidly  together.  Several 
two-plate  cells,  however,  are  usually  set  on  one 
tray. 

Stator.  The  stationary  member,  whether  primary  or 
secondary,  of  any  alternating  current  machine. 

Step-down  Transformer.  A  transformer  in  which  a 
small  current  of  comparatively  great  difference  of 
potential  is  converted  into  a  large  current  of  com- 
paratively small  difference  of  potential.  An  in- 
verted Ruhmkorff  induction  coil. 

Step-up  Transformer.  A  transformer  in  which  a  large 
current  of  comparatively  small  difference  of  po- 
tential is  converted  into  a  small  current  of  com- 
paratively great  difference  of  potential. 

Stevens  Interlocking  Machine.    See  Fig.  1006. 

Stick  Relay.  A  relay  of  the  ordinary  type  so  connected 
that  its  armature  closes  a  circuit  through  its  own 
coils;  that  is,  there  are  two  paths  provided  for  the 
current,  as  shown  in  the  diagram.  One  path  is 
from  battery  B  through  wire  I,  key  X  (when  de- 
pressed), wire  2,  relay  coil  A,  wire  3,  key  Y,  wire  4 
and  back  to  battery.  This  energizes  the  relay  and 
closes  contacts  v  and  w.  Contact  v  being  closed 
current  flows  from  B  through  wires  i  and  5,  con- 


tact  v,  wire  2,  and  through  the  coil  and  back  to 
battery  as  before.  If  now  key  X  is  opened,  the 
relay  will  remain  energized,  current  still  passing 
through  its  armature  contact  and  coil.  Thus  to 
one  testing  the  relay  by  means  of  key. X  it  seems 
to  "stick;"  seems  to  remain  closed  by  reason  of 
some  abnormal  cause,  after  its  circuit  has  been 
opened.  When  the  key  Y  is  depressed  the  battery 
is  completely  cut  off,  the  relay  is  de-energized 
and  the  "stick"  circuit  is  broken  at  v. 

Stock  Rail.  In  a  "split"  switch  either  of  the  two  im- 
movable rails,  as  distinguished  from  the  movable 
"point"  rails. 

Stop  (noun).     See  Automatic  Stop. 

Storage  Battery.  A  collection  of  storage  cells  by  which 
electrical  energy  is  transformed  into  chemical  po- 
tential energy  as  a  result  of  electrochemical  action, 
and  by  which  chemical  potential  energy  is  trans- 
formed into  electrical  energy  as  a  result  of  similar 
electrochemical  action  in  the  reverse  direction. 
Theoretically  the  storage  battery  is  in  its  original 
condition  at  the  end  of  the  cy.cle  of  operation  and 
is  thereby  distinguished  from  a  primary  or  regen- 
erative battery  where  the  element  does  not  work 
in  a  continuous  cycle,  but  has  to  have  new  material 
either  in  whole  or  in  part  mechanically  supplied  to 
it  at  the  end  of  the  discharge  in  order  to  put  it  in 
the  same  condition  as  at  the  start.  See  pages  326- 
334;  Figs.  2243-2296. 


THE   SIGNAL  DICTIONARY 


Sir-Tap 


Straight  Arm  Compensator.  See  Compensator.  See 
Figs,  i I/5-H/5,  11/7-1178. 

Style  "A"  Interlocking  Machine.  A  term  sometimes 
applied  to  a  Standard  interlocking  machine,  which 
see. 

Suspended  Signal.  A  signal  suspended  from  an  over- 
head signal  bridge,  or  other  high  structure.  See 
Figs.  3444-3446. 

Switch  (noun),  d)  A  pair  of  movable  track  rails,  with 
their  fastenings  and  operating  rods,  providing  the 
means  for  making  a  path  over  which  to  move  an 
engine,  car  or  train  on  either  of  two  diverging 
tracks.  (2)  A  device,  in  electrical  connections,  to 
provide  means  for  closing  a  path  for  the  flow  of 
current  in  any  one  of  two  or  more  circuits.  Com- 
monly a  bar,  pivoted  at  one  end,  which  may  be 
moved  so  as  to  touch  any  one  of  two  or  more  con- 
tacts on  as  many  different  conductors. 

Switch  Adjustment.  A  device  for  reducing  "over- 
stroke"  at  a  switch.  See  Figs.  1513-1521.  See 
Overstroke. 

Switch  and  Lock  Movement.  In  mechanical  interlock- 
ing an  arrangement  of  rods  and  levers  by  which 
a  single  stroke  of  a  lever  performs  three  operations: 
unlocks  the  switch,  moves  it  and  locks  it  again. 
See  Figs.  1445-1450,  1484. 

Switchboard.  A  slab  of  slate  or  marble  on  which  are 
mounted  the  necessary  switches,  meters  and  other 
apparatus  required  for  regulating  and  controlling 
the  electric  current  in  a  power  house,  sub-station 
or  similar  place.  The  switches  and  other  appa- 
ratus are  mounted  on  the  front  of  the  switchboard, 
and  the  connections  and  bus  bars  are  mounted  on 
the  back.  Large  switchboards  are  usually  divided 
into  a  number  of  separate  panels.  See  Figs.  2890- 
2899,  etc. 

Switch  Box.  The  familiar  name  for  a  circuit  controller 
at  a  switch,  which  is  contained  in  an  iron  box. 
This  box  is  mounted  on  a  long  tie  about  three  feet 
from  the  nearest  rail  of  the  track  and  is  connected 
to  the  point  of  the  switch  by  a  rod.  The  opening 
of  the  switch  makes  or  breaks  an  electrical  contact 
in  the  box.  See  Figs.  2416-2462. 

Switch  Circuit  Controller.  See  Switch  Box;  Electric 
Selector. 

Switch  Indicator.  A  device  to  indicate  visually  or  au- 
dibly, or  both,  to  the  person  moving  an  isolated 
switch,  whether  or  not  a  train  has  entered  or  is 
approaching  the  block  in  which  the  switch  is  situ- 
ated, and  if  it  is  permissible  to  open  the  switch. 
Used  principally  in  connection  with  automatic 
block  signals.  The  visual  indicator  consists  of  a 
pair  of  magnets  and  an  armature,  to  which  is  at- 
tached a  small  movable  disk  or  miniature  sema- 
phore arm.  The  whole  apparatus  is  enclosed  in  a 
weatherproof  case,  havin/j  a  glass  front,  which  is 
mounted  on  a  post  near  the  switch  stand.  The 
magnet  coils  are  energized  by  a  line  wire  circuit 
which  extends  back  at  least  two  full  block  sections, 
and  which  passes  through  normally  closed  contacts 
on  all  the  intervening  track  relays  or  through 
normally  closed  contacts  on  the  home  signal  arms. 
When  this  circuit  is  broken  by  the  presence  of  a 
train  anywhere  within  the  limits  of  the  circuit, 
which  would  open  one  or  more  contacts,  the  arma- 
ture drops  and  moves  the  disk  or  semaphore  arm 
into  the  position,  indicating  the  approach  of  a  train 
and  giving  warning  against  opening  the  switch. 
The  audible  warning  is  given  by  a  vibrating  bell 


connected  through  a  similar  circuit.  The  bell,  how- 
ever, is  usually  arranged  to  ring  only  when  a  train 
is  approaching  the  block  and  is  cut  out  as  the  train 
enters  the  block.  The  line-wire  circuit  for  both 
the  audible  and  the  visual  indicator  is  carried  bad: 
far  enough,  so  that  warning  of  the  approach  of  .1 
train  will.be  given  at  the  switch  before  the  train 
comes  in  sight  of  the  distant  signal  controlled  by 
the  first  home  signal  in  the  rear  of  the  switch.  Set* 
Figs.  2630-2674. 

Switch  Instrument.  See  Switch  Box  and  Electric  Se- 
lector. 

Switch  Lock,  Electric.     See  Electric  Switch  Lock. 

Switch  Rod.    See  Switch. 

Switch  Tender.  A  person  who  tends  switches.  Ap- 
plied to  attendants  of  ground  switches,  which 
usually  are  not  interlocked.  The  attendant  in  an 
interlocking  tower  moves  and  controls  switches, 
as  well  as  signals,  but  his  designation  is  signal- 
man. 

Sykes'  Lock  and  Block  Instrument.  The  controlled 
manual  block  signal  apparatus  invented  by  W.  R. 
Sykes  in  England,  and  the  first  used  in  America. 
A  few  Sykes'  instruments  were  installed  on  the 
New  York  Central  as  early  as  1882,  but  these  have 
since  been  replaced  by  later  designs.  The  Colemar, 
machine  embodies  all  of  the  features  of  the  Sykes 
machine  and  a  number  of  additional  safeguards. 
The  Sykes  system,  as  used  on  the  New  York  Cen- 
tral, was  applicable  only  to  double-track  roads. 
since  the  release  is  accomplished  while  a  train  is 
passing  over  a  short  releasing  track  circuit,  which 
in  the  case  of  a  single-track  road  would  release  the 
machine  ahead  of  the  train  as  well  as  in  the  rear 
and  might  result  in  allowing  two  trains  moving 
in  opposite  directions  to  enter  the  block  at  oppo- 
site ends  at  the  same  time.  See  Controlled  Manual 
Block  System. 

Synchronism.  A  simultaneous  occurrence  of  any  two 
events.  An  a.  c.  motor  is  said  to  be  synchronous 
when  its  rotor  revolves  at  the  same  speed  as  the 
rotor  of  the  generator.  A  synchronism  motor  is 
said  to  be  in  step  with  the  generator. 

Synchronous  Motor.     See  Synchronism. 


Table  Lever.  A  lever  for  working  a  block  signal  very 
near  the  office,  fixed  in  the  telegraph  operator's 
table. 

Tail  Lever.  The  arm  of  the  lever  of  an  interlocking 
machine,  to  which  the  operating  pipe  or  wire  is 
connected.  See  Interlocking  Machine. 

Tang  End.  A  projection  on  the  end  of  a  jaw  or  rod 
one-half  the  length  of  a  pipe  plug,  used  to  stiffen 
the  joint  between  the  pipe  line  and  the  jaw  or  rod 
in  the  same  manner  as  the  pipe  plug,  which  see. 
See  Figs.  1026-1121. 

Tappet,  (i)  (In  an  interlocking  machine  with  vertical 
locking.)  A  bar  operated  directly  or  indirectly  by 
the  lever  or  lever  latch,  which  actuates  or  drives 
the  locking  bars  and  is  locked  by  them.  (2)  (In  an 
interlocking  machine  with  horizontal  locking.)  A 
pivot  or  swing  dog  attached  to  the  locking  bar  and 
actuated  or  locked  by  the  cross-locking.  See  Inter- 
locking Machine. 

Tappet  Circuit  Controller.  The  circuit  controller  op- 
erated by  the  movement  of  the  lever  latch  handle, 
and  usually  by  movement  of  the  tappet. 


Tel-Tor 


THE   SIGNAL  DICTIONARY 


33 


Telegraph.  See  Telegraph  Block  System,  Manual  Block 
System,  Controlled  Manual  Block  System,  Needle 
Telegraph,  Morse  Telegraph. 

Telegraph  Block  System.  "A  series  of  consecutive 
blocks  controlled  by  block  signals  operated  manu- 
ally upon  information  by  telegraph"  (A.  R.  A.). 
Another  name  for  the  Manual  Block  System,  which 
see.  The  American  Railway  Association  has 
adopted  this  term  (as  above),  although  it  is  nol 
strictly  confined  to  a  system  in  which  the  telegraph 
is  the  means  of  communication  between  block  sta- 
tions, bells  or  telephones  being  used  in  some  cases. 

Telephone.  Apparatus  by  which  sounds  (of  the  human 
voice)  are  repeated  at  a  distance.  Used  as  a  means 
of  communication.  See  Manual  Block  System; 
Controlled  Manual  Block  System;  Telegraph  Block 
System.  See  Fig.  3551- 

Telephone  Train  Dispatching.  See  Selective  Dispatch- 
ing or  Signal  System. 

Terminal  Board.  A  collection  of  binding  posts  mounted 
on  a  slab  or  board  to  which  the  ends  of  a  number 
of  wires  may  be  attached  and  interconnected,  as 
desired,  by  short  pieces  of  wire  or  metal  strips 
called  jumpers. 

Thomas  Interlocking.  A  system  of  pneumatic  inter- 
locking using  compressed  air  only  at  a  pressure  of 
80  Ibs.  per  square  «nch.  It  depends  for  its  opera- 
tion on  a  difference  of  pressure  of  10  Ibs.  between 
the  pipes,  both  in  working  a  function  and  obtain- 
ing the  indication.  This  system  was  invented  by 
J.  W.  Thomas,  Jr.,  and  orginally  installed  at  Nash- 
ville on  the  Nashville,  Chattanooga  &  St.  Louis. 

Threaded  Rod.  A  term  sometimes  applied  to  a  Throw 
Rod,  which  see. 

Three-phase  Currents.  Three  alternating  currents 
differing  in  phase  from  one  another  by  one-third 
of  a  cycle. 

Three-position  Automatic  Block  Signals.  A  system  of 
automatic  block  signals  designed  to  provide  the 
protection  of  distant  signals  without  the  duplica- 
tion of  signal  arms  usually  involved.  Each  signal 
arm  is  so  arranged  that  it  may  be  put  in  any  one 
of  three  positions;  horizontal  for  stop;  inclined  45 
deg.  for  "caution"  and  vertical  for  proceed.  The 
signal  goes  to  the  stop  position  when  a  train 
enters  the  block;  when  the  train  has  cleared  the 
block  it  moves  to  the  caution  position,  and  it  re- 
mains in  that  position  until  the  next  signal  in  ad- 
vance moves  to  the  caution  position,  when  it  goes 
to  "clear."'  A  train  is  thus  always  protected  by  n 
stop  signal  in  the  rear  and  a  caution  signal  one 
block  further  back.  Three-position  automatic  block 
signals  were  first  introduced  on  the  Pennsylvania 
Lines  West  of  Pittsburgh  in  the  year  1900. 

Three-position  Signal.  A  semaphore  signal  arranged 
to  give  three  different  indications.  See  Figs.  136- 
141,  165-1/6.  In  a  common  form  (manually  oper- 
ated) the  horizontal  position  of  the  arm  indicates 
"stop,"  the  arm  inclined  downward  3/^2  deg.  "cau- 
tion" (permissive  block  signaling)  and  inclined 
downward  about  75  deg.  "proceed"  (speed  not  lim- 
ited). On  a  few  roads  the  arrangement  is  hori- 
zontal "stop;"  upward  45  deg.,  "caution;"  down- 
ward, 45  deg.,  "proceed"  (speed  not  limited).  In 
automatic  three-position  signals  (which  see)  and 
in  some  manual  signals  the  proceed  position  is 
vertical  (90  deg.  from  horizontal),  but  the  arm  is 
made  to  stand  clear  of  the  post,  so  that  the  engine- 
man  may  see  that  it  is  not  missing. 


Throw  Rod.  The  rod  connecting  a  switch  to  its  oper- 
ating mechanism.  The  throw  rod  is  connected  to 
the  head  rod  of  the  switch  by  a  switch  adjustment, 
which  see.  See  also  Figs.  1513-1521. 

Tie  Plate.  In  interlocking  work,  an  iron  plate  fastened 
to  the  upper  surface  of  a  tie  or  sleeper  and  extend- 
ing across  the  track  beneath*  the  rails.  Used  prin- 
cipally at  switches  and  movable  point  frogs  in  con- 
nection with  rail  braces,  butt  straps  and  slide 
plates,  to  hold  the  track  to  gage. 

Tie  Strap.  A  flat  iron  rod  or  bar,  fastened  by  spikes 
or  lag  screws  to  the  ties  (as  at  a  switch)  to  hold 
the  ties  in  position. 

Tie  Wire.  A  short  piece  of  wire  used  to  tie  line  wires 
to  insulators.  See  Figs.  3005-3006. 

Time-Interval  System.  The  rules  under  which  trains 
are  run  where  there  is  no  block  system.  To  obvi- 
ate the  danger  of  rear  collisions  in  consequence  of 
unexpected  delays  to  trains  between  stations  the 
attendant  at  each  station  sees  that  a  prescribed 
interval,  usually  five,  seven  or  ten  minutes,  is  main- 
tained between  trains.  This  interval  is  intended  to 
allow  time  enough  for  the  protection  of  a  delayed 
train  by  sending  back  a  flagman  to  warn  any  fol- 
lowing train.  At  night  the  flagman  carries  a  red 
lantern.  Both  night  and  day  he  carries  torpedoes 
with  which  to  give  audible  signals,  and  fusees, 
which  see. 

Time  Lock.  A  device  similar  in  purpose  to  a  time  re- 
lease. It  is  usually  automatic  in  action.  See  Time 
Release.  See  Figs.  2831-2859. 

Time  Release.  A  device  for  releasing  an  electric  lock 
(on  a  signal  or  other  lever)  when  it  remains  locked 
because  of  abnormal  conditions  and  thereby  delays 
traffic.  See  Screw  Release.  See  Figs.  2831-2859. 

Time-Table.  The  statement  of  stations,  trains  and 
times,  issued  by  the  superintendent  of  a  railway 
for  the  guidance  of  the  men  in  charge  of  trains.  It 
is  the  authority  for  the  movement  of  regular  trains. 
A  schedule — one  column  in  a  time-table — prescribes 
the  class,  direction,  number  and  movement  of  a 
regular  train,  showing  where  and  when  it  begins 
its  trip  and  the  -time  at  each  station.  On  a  single- 
track  railway  the  rules  regulating  meeting  points 
are  a  vital  element  of  the  time-table;  but  where 
the  block  system  is  used  these  and  many  other 
time-table  rules  become  of  minor  importance,  as 
provisions  for  safety,  though  they  still  remain  im- 
portant as  matters  of  convenience.  Time-tables 
contain  local  or  temporary  rules  modifying  the 
general  train  rules  contained  in  the  Standard  Code 
of  Rules. 

Tommy  Bar.     See  Fig.  3559. 

Torpedo.  An  explosive  cap,  the  size  of  a  small  watch, 
to  be  fastened  on  the  top  of  a  rail  of  the  track,  to 
be  exploded  by  the  pressure  of  the  first  wheel  of 
an  approaching  engine  or  train.  .The  detonation 
indicates  "stop."  Torpedoes  are  used  when,  by 
reason  of  fog,  snow  or  darkness,  a  visible  stop 
signal  may  not  be  seen  by  the  engineman.  See 
Figs.  35H-35I2. 

Torpedo  Placer.  An  apparatus  for  putting  torpedoes 
in  position  to  be  exploded  by  the  passage  of  a 
wheel  of  a  locomotive  or  other  vehicle.  In  the  do- 
sign  shown  in  Figs.  3513-3514  the  torpedo  lies  be- 
neath an  anvil  which  is  at  the  side  of  the  rail  and 
is  depressed  by  the  outer  part  of  the  tread  of  i 
wheel.  On  British  railways  where  torpedoes  arc 
usually  placed  by  hand  by  attendants  (in  times  of 
fog)  a  hand  placing-apparatus  is  sometimes  used,  to 


34 


THE   SIGNAL  DICTIONARY 


Tor-Tra 


relieve  the  attendant  from  the  dangerous  duty  of 
crossing  tracks,  as  is  necessary  in  the  case  of  a  four- 
track  line. 

Torque.  The  moment  of  a  force  causing  rotation;  the 
product  of  the  force  and  the  distance  from  the 
point  of  application  of  the  force  to  the  center  of 
rotation.  The  mechanical  rotary  or  turning  force 
which  acts  on  the  armature  of  a  generator,  motor 
or  other  machine  and  causes  it  to  rotate.  In  the 
case  of  the  rotor  of  a  generator  or  motor  the 
torque  is  equal  to  the  radius  of  the  armature 
multiplied  by  the  pull  at  the  circumference,  or 
the  radius  of  its  pulley  multiplied  by  the  pull  at 
the  circumference  of  the  pulley.  A  torque  is  ex- 
erted on  the  shaft  of  a  motor  from  the  electro- 
magnetic action  or  pull  at  the  periphery  of  the 
armature.  The  torque  is  usually  measured  in 
pounds  of  pull  at  the  end  of  a  radius  or  arm  i  ft. 
in  length. 

To  the  Rear  of  a  Signal.  The  section  of  track  occupied 
by  a  train  before<it  has  passed  a  signal. 

Toucey  &  Buchanan  Interlocking.  One  of  the  earliest 
American  interlocking  machines.  Used  on  the 
New  York  Central;  now  superseded. 

Tower.  A  common  name  for  the  building  from  which 
signals  are  operated.  Usually  two  stories  high, 
with  the  signalman's  room  in  the  second  story; 
sometimes  called  a  cabin.  Some  interlocking 
towers  containing  machines  of  many  levers,  are 
from  50  ft.  to  100  ft.  long.  See  Figs.  3884-3908. 

Track  Bond.     See  Rail  Bond. 

Track  Circuit.  An  electric  current  flowing  through 
the  rails  of  a  railway  track.  In  a  typical  track 
circuit,  Fig.  326,  the  current  flows  from  the  bat- 
tery to  the  nearest  rail  of  the  track,  thence  to  the 
other  end  of  the  track  circuit  section;  thence  by 
wire  to  the  track  relay  (controlling  a  signal)  back 
by  a  wire  to  the  farther  rail,  and  by  that  rail  back 
to  the  battery.  Each  rail  is  made  electrically  con- 
tinuous from  one  end  of  the  track-circuit  section 
to  the  other  by  metallic  bonds  at  the  joints,  and 
at  the  ends  of  the  section  insulated  joints  are  used. 
See  Rail  Bond;  Insulated  Rail  Joint.  See  Figs. 
406-483. 

Track  Circuit  Locking.  Electric  Locking,  which  see, 
accomplished  by  track  circuits. 

Track  Indicator.  A  map-like  reproduction  of  railway 
tracks,  made  on  transparent  glass,  controlled  by 
track  circuits  so  arranged  beneath  the  glass  as  to 
indicate  automatically,  for  defined  sections  of  track, 
by  distinctive  colors,  whether  or  not  such  sections 
are  occupied  by  a  vehicle  or  vehicles.  Used  prin- 
cipally at  interlocking  plants.  See  Indicators,  Figs. 
2550-2674. 

Track  Instrument.  A  lever  fixed  to  a  tie,  to  be  moved 
by  the  weigh't  of  the  wheel  of  a  passing  train,  or 
by  deflection  of  a  rail  under  the  weight  of  the 
wheels,  and  designed  to  open  or  close  an  electric 
contact  in  an  electric  circuit.  Used  to  control  cir- 
cuits for  highway  crossing  bells,  annunciators,  etc. 
In  automatic  block  signaling  without  track  circuits 
(formerly  in  use  in  New  England)  two  such  instru- 
ments are  required  for  each  signal,  one  at  the  en- 
trance to  the  block,  in  which  the  contact  is  norm- 
ally closed  and  is  opened,  by  the  passage  of  a  train, 
to  move  the  signal  to  the  stop  position,  and  the 
other,  at  the  outgoing  end  of  the  block,  in  which 
the  contact  is  normally  open  and  is  closed,  by  the 


passage  of  the  train,  to  restore  the  signal  to  the 
clear  position.  The  two  instruments  are  connected 
with  the  signal  mechanism  by  wire  strung  on  poles. 
Wire-circuit  signals  were  used  as  early  as  1871, 
but  are  now  obsolete,  having  been  generally  super- 
seded by  Track  Circuit  Signals.  See  Figs.  2232- 
2242,  2487-2488. 

Track  Model.  In  an  interlocking  machine,  a  map-like 
miniature  reproduction  (with  movable  pieces  repre- 
senting the  switches)  of  the  tracks  in  which  are 
the  switches  controlled  by  the  machine.  See  Figs. 
2615,  2625-2628.  Following  each  movement  of  a 
switch,  the  attendant,  who  has  moved  the  lever, 
sees  the  effect  of  his  action  repeated  on  the  model. 

Track  Relay.     A  relay  in  a  track  circuit.     See  Relay. 

Traffic  Lever.     A  Check  Lock  Lever,  which  see. 

Traffic,  Maximum,  on  a  Block  Signal  Line.  See  Block 
Signaling  for  Maximum  Traffic. 

Trailing  Point  Switch.  The  opposite  of  Facing  Point 
Switch,  which  see. 

Train  Describer.  An  electrical  instrument  designed  to 
give  information  regarding  the  origin,  destination, 
class  or  character  of  trains,  engines  or  cars  moving 
or  to  be  moved  between  defined  points.  Used  in 
signal  towers  to  announce  trains  from  one  tower  to 
another,  or  from  train  sheds  to  towers  or  dispatch- 
ers' office.  See  Figs.  2605-26*06. 

Train  Dispatcher.  The  officer  who  supervises  the 
movement  of  the  trains  on  a  given  division  of  rail- 
way, sending  telegraphic  orders  to  the  conductors 
and  enginemen  of  trains  for  which  the  time-table 
does  not  give  full  authority.  On  a  single-track 
line  he  must  by  this  means  adjust  the  relative  rights 
of  opposing  regular  trains  when  one  or  both  is 
behind  time  and  those  of  all  extra  trains. 

Train  Order  Signal.  A  fixed  signal — semaphore  or 
other — used  at  a  telephone  or  telegraph  station  to 
indicate  to  a  train  that  it  must  stop  there  to  receive 
a  telephone  or  telegraphic  order  affecting  its  right 
to  the  road.  Such  a  signal  is  usually  manually 
operated  by  the  telephone  or  telegraph  operator 
in  charge  of  the  station.  In  the  selective  telephone 
or  telegraph  train  dispatching  system,  however,  it 
is  controlled  by  a  selector  operated  over  the  tele- 
phone or  telegraph  circuit  by  the  dispatcher  from 
a  distant  point.  It  is  equipped  with  an  answer- 
back mechanism  which  indicates  over  the  circuit 
to  the  dispatcher  that  the  board  or  signal  is  set 
to  stop  position.  The  board  cannot  then  be  set 
to  the  clear  position  without  the  consent  and  co- 
operation of  the  dispatcher.  See  Figs.  3319-3327. 

Train  Sheet.  The  sheet — usually  a  single  sheet  for 
each  day  of  twenty-four  hours — on  which  a  train 
dispatcher  records  the  passage  of  all  the  trains,  that 
run  over  his  division  or  district  on  that  day. 
When  filled  up  it  resembles  a  time-table,  with  the 
addition  of  names  of  trainmen,  numbers  of  en- 
gines, etc.  The  train  sheet  at  a  block-signal  sta- 
tion, sometimes  called  a  block  sheet,  is  used  to 
record  the  times  of  the  trains  usually  at  three  sta- 
tions only;  the  station  where  the  record  is  made,  the 
one  before  it,  and  the  one  after  it. 

Train  Staff.  See  Staff  System;  Electric  Train  Staff 
System. 

Train  Stop.  See  Automatic  Stop.  See  Figs.  3691- 
3/00. 

Transformer.  A  device  for  transforming  an  alternating 
current  of  high  voltage  into  an  alternating  current 


Tra-Wat 


THE   SIGNAL  DICTIONARY 


of  the  same  frequency,  but  of  lower  voltage, 
and  greater  amperage  or  vice  versa.  A  transformer 
which  reduces  the  voltage  is  a  step-down  trans- 
former; one  which  increases  the  voltage  is  a  step- 
up  transformer.  The  usual  form  consists  of  two 
separate  coils  of  wire  wound  on  a  soft  iron  core. 
The  coil  carrying  the  impressed  current  is  the 
primary  and  the  other  is  the  secondary.  The  action 
in  the  transformer  is  entirely  inductive,  the  cur- 
rent flowing  in  the  primary  coil  inducing  magnetic 
lines?  of'.force  in  the  core,  which  in  turn  induce  a 
current  in  the  secondary  coil.  The  voltage  in  the 
primary  and  secondary  coils  vary  approximately 
with  the  number  of  turns  of  wire  in  each  and  the 
current  inversely  as  the  number  of  turns.  Thus, 
with  500  turns  in  the  primary  and  100  turns  in  the 
secondary  the  reduction  in  voltage  would  be  5  to  I 
and  the  increase  in  current  would  be  as  I  to  5.  See 
Figs.  2970-2977. 

Transverse  Pipe  Carrier.  A  pipe  carrier  designed  to 
guide  pipe  across  tracks;  usually  supported  on 
ties;  sometimes  called  a  hanging  pipe  carrier.  See 
Pipe  Carrier.  See  G,  H,  K,  L,  N,  Figs.  1205-1233, 
and  Figs.  1242-1254. 

Trick.  A  tour  or  turn  of  duty.  The  "third  trick"  in 
a  telegraph  or  block  signal  station  usually  means 
the  tour  of  duty  from  midnight  to  8  a.  m. 

Trip.  In  automatic  train-stopping  apparatus,  the  bar, 
lever,  or  other  device,  fixed  on  or  near  the  track 
or  roadway,  which  when  in  a  certain  position,  trips 
or  releases  the  apparatus  on  the  vehicle,  by  which 
release  the  setting  of  the  brakes  is  effected. 

Triple-pole  Switch.  A  switch  consisting  of  a  combina- 
tion of  three  separate  switches  for  opening  or  clos- 
ing three  circuits  at  the  same  instant.  A  switch 
employed  to  open  or  close  three  contacts.  A  switch 
employed  to  open  or  close  triphase  circuits. 

Trunking.  The  wooden  casing  used  to  protect  from 
snow  and  from  mechanical  injury  wires,  both  elec- 
trical conductors  and  those  used  to  pull  signal 
arms  when  they  lie  on  or  near  the  surface  of  the 
ground.  See  Figs.  3701-3883. 

Trunnion.  A  cylindrical  projection  on  a  revolving  part 
for  supporting  it  in  a  bearing. 

Tunnel  Signal.  A  signal  designed  to  be  placed  in  a 
tunnel.  It  gives  indications  usually  wholly  by 
colored  lights.  Sometimes  called  a  light  signal.  A 
Pot  Signal,  which  see,  is  sometimes  used  as  a 
tunnel  signal. 

Two-Light  Signal  Aspects  (system  of).  An  arrange- 
ment of  semaphore  signals,  in  which  every  signal 
shows,  at  night,  at  least  two  lights,  as,  for  exam- 
ple, at  a  signal  where  there  is  a  main  route  and 
one  diverging  route.  At  a  block  signal  where 
no  diverging  route  is  to  be  signaled  the  second  or 
lower  light  (never  indicating  proceed)  is  of  use  to 
assist  the  engineman  in  quickly  reading  the  upper 
one.  A  second  arm  may  be  used  as  well  as  a 
second  light,  so  as  to  give  the  desired  aspect  in 
daylight  as  well  as  at  night. 

u 

Unit,  Interlocking.     See  Operated  Unit. 

Up-and-Down  Rod.  The  common  name  for  the  mov- 
able vertical  rod  connecting  a  semaphore  signal 
arm  with  the  operating  mechanism  at  the  base  of 
the  signal  post. 


Upper  Quadrant.  One  of  the  quarters  of  a  circle  above 
its  horizontal  axis;  a  term  used  of  semaphore 
signals,  in  which  the  arm,  normally  horizontal  (in- 
dicating stop)  is  turned  upward  to  give  other  than 
stop  indications. 

V 

Vane  Relay.  A  type  of  alternating  current  relay  in 
which  a  light  metal  disk,  or  vane,  perforated  with 
radial  slots,  is  caused  to  move  between  the  pole 
pieces  of  magnets  to  close  contacts  when  the  mag- 
nets are  energized,  or  open  them  through  the 
falling  of  the  vane  by  gravity,  when  the  magnets 
are  de-energized.  See  Figs.  680-684. 

Variable  Resistance.  A  resistance,  the  value  of  which 
can  be  readily  varied  or  changed.  An  adjustable 
resistance. 

Vault.  Receptacle  for  housing  batteries  in  the  ground 
below  frost  line.  See  Well. 

Vertical  Locking.  Mechanical  locking  arranged  in  a 
vertical  plane.  See  "Standard,"  National  and  John- 
son  Interlocking  Machines. 

Volt.  The  practical  unit  of  measurement  of  electro- 
motive force.  Such  an  electro-motive  force  as  will 
cause  a  current  of  one  ampere  to  flow  through  a 
circuit  with  a  resistance  of  one  ohm.  See  Am- 
pere. 

Voltmeter.  An  instrument  for  measuring,  in  terms  of 
volts,  the  electro-motive  force  of  a  current  of 
electricity.  It  is  similar  in  principle  and  construc- 
tion to  the  Ammeter,  which  see,  but  the  coil  is 
wound  with  many  turns  of  fine  wire  so  as  to  work 
with  very  small  currents  and  a  resistance  of  several 
thousand  ohms  is  usually  placed  in  series  with  it. 
See  Testing  Instruments,  pages  484-489;  Figs.  3515- 
3558. 

w 

Watt.  The  unit  of  electric  power.  The  product  of 
volts  times  amperes.  One  horse-power  is  equal 
to  746  watts. 

Watt  Hour.  The  unit  of  electric  work,  representing 
the  expenditure  of  one  watt  for  one  hour. 

Watt  Meter.  An  instrument  for  measuring  the  powei 
of  an  electric  current  passing  through  any  circuit 
It  is  provided  with  two  sets  of  coils.  One  is  a 
.  current  coil  and  the  other,  suspended  inside  the 
first,  is  free  to  turn.  This  measures  the  voltage  of 
the  current  passing.  The  torque,  produced,  tend- 
ing to  displace  the  revolving  coil,  is  proportional 
to  the  product  of  the  magnetic  fields  developed  by 
the  fixed  and  the  movable  coil  and  therefore  is  pro- 
portional to  the  energy  or  electrical  power  pass- 
ing in  the  circuit.  The  amounj  of  the  displacement 
is  read  by  a  pointer  on  a  graduated  scale. 

The  more  usual  form  is  the  integrating  watt 
meter,  which  records  on  a  series  of  dials,  the  num- 
ber of  watt  hours  of  power  consumed.  The  Thomp- 
son integrating  watt  meter,  which  is  the  best- 
known  type,  is  essentially  a  small  motor,  the  speed 
of  which  is  proportional  to  the  power  in  the  cir- 
cuit. The  entire  current  flows  through  the  field 
coils,  which  are  wound  with  heavy  wire.  The 
armature,  which  is  wound  with  very  fine  wire,  is 
in  series  with  a  very  large  resistance  placed  across 
the  mains.  The  armature  shaft  carries  a  copper 
disk,  revolving  between  the  poles  of  three  drag 
magnets,  which  produce  a  constant  retarding  force. 


THE   SIGNAL   DICTIONARY 


Wel-Zar 


The  other  end  of  the  armature  shaft  carries  a  worm 
to  drive  the  recording  gear.  Such  a  meter  will 
register  within  2  per  cent  for  long  periods  without 
adjustment. 

Well.  A  large  concrete  or  masonry  receptacle  for  bat- 
teries to  house  them  in  the  ground  below  the  frost 
line.  Commonly  made  complete  and  sunk  to  place. 
See  Battery  Chute.  See  Figs.  2400-2409. 

Wheel.     See  Chain  Wheel. 

Wide  Jaw.     See  Figs.  1026-1121. 

Wire  (Electric  Conductors).  For  telegraph  lines  gal- 
vanized iron  wire  of  size  8  or  9,  B.  W.  G.,  is  in  ex- 
tensive use.  Copper  wire  of  size  10,  12  or  14. 
B.  &  S.,  is  also  much  used.  Line  wires  usk;d  in 
automatic  block  signaling  are  of  size  10,  12  or  14, 
B.  &  S.,  but  a  "common  wire"  serving  as  the  re- 
turn portion  of  a  number  of  circuits  is  usually 
larger.  All  of  these  are  sometimes  covered  with 
a  continuous  insulating  covering.  Wires  inside  of 
buildings  and  those  connecting  instruments  and 
lines  to  the  rails  of  the  track  are  of  copper,  insu- 
lated. See  Cable,  Copper-Clad  Wire,  Insulated 
Wire.  See  Figs.  3909-3924. 

Wire  Carrier.  A  roller  or  pulley  supported  in  a  frame, 
used  as  a  support  and  guide  for  a  wire  line.  See 

Figs.    I309-I335- 

Wire  Compensator.  In  a  mechanical  interlocking  plant, 
a  device  for  automatically  keeping  the  length  of  a 
wire  uniform  under  variations  in  temperature.  See 
Compensator.  See  Figs.  1409-1410. 

Wire,  Conductivity.    See  Table  on  page  514. 

Wire  Eye.     See  Figs.  1305-1306. 

Wire  Gage.    See  Table  on  page  514. 

Wire  Run.  In  an  interlocking  plant,  an  assemblage  of 
wire  lines,  with  their  carriers  and  foundations,  in 
a  common  course. 

Wire,  Signal.  In  manually  operated  semaphore  signals, 
the  wire,  usually  of  steel,  about  No.  8  or  No.  9, 
B.  W.  G.,  connecting  a  signal  arm  with  its  lever 
in  the  cabin.  It  is  supported  on  wire  carriers  fixed 
to  short  stakes  set  in  the  ground;  or,  if  such  are 
conveniently  situated,  on  the  heavier  foundations 
used  to  support  pipe  connections.  In  either  case 
the  wire  may  be  covered  with  trunking,  which  see. 
The  wire  by  which  a  signal  is  pulled  to  the  clear 
position  is  called  the  front  wire;  that  used  to  pull 
it  to  the  stop  position  is  the  back  wire.  This  last 


is  sometimes  omitted.  In  Europe  it  is  generally 
omitted  as  the  counterweight,  close  to  the  signal 
arm,  is  depended  on  to  pull  the  arm  to  the  stop 
position  when  the  front  wire  is  slackened.  In 
case  of  breakage  of  the  front  wire,  the  counter- 
weight is  designed  to  pull  the  arm  to  the  stop  posi- 
tion. Where  a  signal  wire  line  must  be  sharply 
turned  to  one  side,  a  piece  is  cut  out  and  a  chain 
inserted  in  place  of  the  wire,  and  the  chain  runs 
around  a  grooved  wheel.  In  consequence  of  the 
difficulty  of  adjusting  signal  wires,  when  they 
are  lengthened  or  shortened  by  changes  in  tem- 
perature, rods  (pipe)  are  now  generally  used,  ex- 
cept for  signals,  very  far  from  the  cabin.  For  these 
signals  at  a  distance  the  wire  must  be  adjusted 
when  necessary  by  screws  in  the  tower;  or  an  au- 
tomatic wire  compensator  is  used.  To  avoid  the 
difficulties  connected  with  long-distance  signal  con- 
nections many  companies  use,  to  operate  distant 
signals,  electric  motors  (fixed  at  the  signal),  such 
as  are  used  for  automatic  block  signals.  These 
are  controlled  by  an  electrical  connection  from 
the  tower. 

Wires,  Sizes  of.  The  diameters  and  weights  of  the  dif- 
ferent sizes  of  wire,  according  to  the  Birmingham 
and  the  Brown  &  Sharpe  wire  gages,  with  other 
information  are  given  in  the  tables  on  page  514,  etc. 

"Wireless"  Automatic  Block  System.  A  term  used  to 
define  that  arrangement  of  automatic  block  signals 
in  which  line  wires  for  the  control  of  distant  sig- 
nals are  dispensed  with.  The  home  signal  con- 
trols the  clearing  of  the  distant  signal  by  changing 
the  polarity  of  the  track  circuit  which  extends 
from  the  home  back  to  its  distant.  When  the  po- 
larity is  changed  there  is  a  brief  period  of  time 
during  which  no  current  flows.  To  prevent  this 
from  opening  the  signal  circuit  and  wrongfully 
putting  the  home  signal  in  the  stop  position  a 
"slow-acting"  relay  or  slow  releasing  slot  is  used; 
before  the  armature  falls  the  current  is  restored. 

Wood  Filler.     See  Insulated  Rail  Joint. 


Z  Armature.  An  armature  (of  an  electro-magnet) 
shaped  like  the  letter  Z;  used  in  enclosed  disk 
signals,  switch  indicators,  etc.  Se.e  Figs.  513-520. 


STANDARD  SYMBOLS  AND  SIGNAL  INDICATIONS 


STANDARD  SYMBOLS 
Pages  2-13  Figures  1-224 


SYMBOLS  FOR  SIGNALS  .  .  . 
LOCATION  SYMBOLS  .... 
SYMBOLS  FOR  CIRCUIT  PLANS 


Pages 
2-  3 

4-  7 
8-13 


Figures 
1-  33 

34-138 
139-224 


SIGNAL  INDICATIONS 
Pages  14-20  Figures  225-307 


SEMAPHORE,  BLOCK       .    .    . 

DISK,  BLOCK 

SEMAPHORE,  INTERLOCKING 


SIGNAL  LOCATIONS  WITH  REFERENCE  TO  TRACKS 
GOVERNED 


Pages 
14-15 

15 
16-18 

18-20 


Figures 
225-241 

242-249 
250-276 

277-307 


STANDARD    SYMBOLS. 


Figs.  1-13 


NON  -AUTOMATIC. 

SEMI-AUTOMATIG. 

SPECIAL 

OPERATING. 

SLOTTED. 

(POWER.) 

AUTOMATIC 

REQUIRES 

MECHANICAL 

POWER 

(MECH.) 

STICK. 

NON-STICK 

(POWER) 

REFERENCE 
TO  NOTES. 

^ 

^i 

L__ 
— 

--| 

pa 

B::: 

i 

j_  , 

L.:Q] 

^? 

i 

i 

i 

§ 

1 

Z 

3 

i 
i 

4 

i 

5 

6 

7 

Two 
POSITION 

2-  POSITION. 
OT060*OT070 

1  , 
i 
1  J 

^3 

hj 

A3 

ti 

n 

A6 

toD 

SIGNALING. 

OT075'OT090 

A 

Al 

A2 

1 

A4 

A5 

A7 

2-  POSITION. 

L~n 

31 

tn 

f 
B3 

tn 

JJJ 

in 

tun 

OT090 

B 

Bl 

B2 

1     B4- 

B5 

B6 

B7 

2-  POSITION. 

I^J 

S 

SI 

— 

C3 

^ 

1     C4 

SI 

si 

C6 

ts 

THREE 

Dn  c  ITTI  Hki 

OT045 

C 

Gl 

02 

C5 

C7 

POSITION 

SIGNALING. 

2-  POSITION. 

4> 

i* 

1      Dl 

\/b 

& 

\      D3 

& 

1      D4 

I,/? 

> 

^ 

1     D6 

^\ 

45  TO  90 

^ 

\Q/ 

p^- 

f 

\\F 

D 

\      D2 

1      DSJ 

1      07 

3-  POSITION. 

^ 
^Sw 

S3 

SI 

— 

E3 

t 

3 

3S 

] 

^1 

hgg 

OT045T090 

E 

El 

E2 

rE4 

E5 

E6 

E7 

NOTE:  ARMS  SHOULD  ALWAYS  BE  SHOWN  IN  NORMAL  POSITION. 

^^|    SPECIAL-  3  POSITION    NON-AUTOMATIC, 

OTO  45  . 

E24 

SEMI-AUTOMATIC 

STICK  ,  45 

TO  90. 

^<]    SPECIAL-  3  POSITION   NON-  AUTOMATIC, 

0  TO  45  . 

JE25 

SEMI  -AUTOMATIC 

NON-STICK,  45  TO  90. 

1    ABSOLUTE 

STOP  SIGNAL. 

~T   DISTANT 

SIGNAL. 

i 

i 

i 

i 

!      >    PERMISSIVE 

STOP   SIGNAL. 

I£   TRAIN   ORDER  SJGNAL. 

i 

i 

i 

ENDS 

OF  BLADES  IN  SYMBOLS   ARE  TO  BE  OF  THE  ACTUAL  FORMS   USED   BY  THE 

ROAD 

CONCERNED.  IF  NOT   SPECIFIED  THE  ABOVE 

FORMS 

WILL  BE  USED  ON  PLANS. 

r^^  FIXED  ARM. 

i  j 

-I 

*ii 

*i" 

*"  A  "* 

i*** 

^ 

fr 

hiq 

]  UPPER  QUADRANT  SIGNAL,     y 

V 

// 

t    ' 

/ 

A 

f 

•    H 

/? 

P 

\ 

i 

"]  LOWER  QUADRANT  SIGNAL. 

1 

/ 

\ 

!/3 

} 

1 

/ 

/ 

i 

V 

f 

t 

i                                     \                                       n 

/ 

\ 

/3 

VERTICAL                             t 

/ 

^ 

p  j 

i    v 

i-  J 

!O                      >  MARKER  LIGHTS. 

DIAGRAMS  OF  PROPORTIONS  FOR  MAK- 

'"j  STAGGERED) 
i  1                 / 

ING  SYMBOLS 

FOR   SIGNAL   BLADES  . 

0! 

Figs.    1-13.     Symbols   for   Signals. 


Figs.  14-33 


STANDARD    SYMBOLS. 


GROUND 
MAST. 


GROUND  MAST  WITH 
BRACKET  ATTACHMENT. 


RING  ENCLOSED 
CHARACTERISTICS 

MEAN    LIGHT  SIGNAL 
ONLY. 


- 


___. 


OFFSET 
BRACKET    POST. 


POT    SIGNAL 


I- — i  h— - 

!         J  ' 

i '  I 

i  i 

i  i 


BRACKET 
POST. 


SUSPENDED 
MAST. 


Disc  SIGNALS. 


€ 


HOME 
PROCEED  . 


HOME 
STOP. 


DISTANT          DISTANT          DOUBLE 
PROCEED.         CAUTION.       FUNCTIONED, 


PRESENT  SISNAL  TO  BE  REMOVED 


PRESENT  SIGNAL  TO  REMAIN. 


RELATION  OF  THE  SIGNAL  TO  THE  TRACK  AND  THE  DIRECTION  OF  TRAFFIC 


n 


RIGHT  HAND   LOCATIONS. 


RIGHT  HAND  SIGNAL. 


LEFT  HAND  SIGNAL. 


LEFT  HAND    LOCATIONS. 


D 


RIGHT  HAND  SIGNAL. 


LEFT  HAND  SIGNAL 


Figs.   14-33.     Symbols  for  Signals  (continued). 


STANDARD    SYMBOLS. 


Figs.  34-76 


1 

INSULATING  RAIL  JOINTS. 

IT                                                      r* 

•                            "                          •                           • 

-J                                                                                                                           La  

TRACK   CIRCUITS  IN                TRACK   CIRCUIT   ON                TRACK   CIRCUIT  ON 
BOTH    DIRECTIONS.               LEFT  ,  NONE  ON  RIGHT.            RIGHT,  NONE  ON  LEFT. 

IMPEDANCE  BOND.        TRAFFIC  DIRECTION.              TRACK   PAN. 

CD 

.                                      V             A             A.           yV             A             A             I 

^                   x  —  —  y^  —  /^  —  s^  —  'x.  —  s 

•      .     ^B                 ^^ 

1 

STATION.             CROSSING  GATE.             SIGNAL          SIGNAL  SUB-STATION. 

(UNLESS  OTHERWISE  SPECIFIED.)                                                  POWER  STATION  . 

45 

v    •'•/.-        -     -       -      ^        /      1 

j            | 

/                      \ 

• 

>      I    ; 

TUNNEL.     BRI 
NO' 

T 

V             / 

'                \         /              \             )  '                \ 
MILE  POST. 
DGE  OR  VIADUCT.    DRAWBRIDGE.            LIFT  BRIDGE. 

FE  I    STATE  WHETHER   DECK,  HALF  -THROUGH  OR  THROUGH  BRIDGE. 
T                           V 

1 

OVERHEAD 
BRIDGE. 

A 

SIGNAL               HIGHWAY             RAILWAY           PROPOSED  RAILWAY 
BRIDGE.              CROSSING.            CROSSING.                CROSSING. 
NOTE:  SPECIFY  WHETHER  STEAM  OR  ELECTRIC  Rv.CROSSiNt 

JL^ 

@          o  i            A               ra 

MAIL  CRANE.      WATER  TANK.   WATER  COLUMN.  TRACK  INSTRUMENT.     TORPEDO  MACHINE. 

TRAIN  STOPS. 

A       A       A       A       A 

~                 (sf                 W                 U                 U           STOP. 

VJ  L_tl  A  K  . 

NON-  AUTOMATIC.                 SLOTTED.           SEMI-           AUTOMATIC. 
MECHANICAL.          POWER  .                              AUTOMATIC  . 

1  ^^ 

+  _—  -^                      \    -^-^^                          ^-—  ^ 

DO 

POWER  SWITCH 
MACHINE. 

INSULATED                 TURN-OUT                  ELECTRIC 
SWITCH  ROD.          AND  SWITCH  STAND.        SWITCH  LOCK. 

Figs.   34-76.     Location    Symbols. 


Figs.  77-100 


STANDARD    SYMBOLS 


-CAPACITY 


RELAY  Box.         JUNCTION  Box.        TERMINAL  Box.  LIGHTNING  ARRESTER 

Box. 


GAPACITY- 


3~) CAPACITY 

^ — ' 

BATTERY  CHUTE  . 


RELAY    BOX   CAPACITY  - 
CHUTE    CAPACITY 


RELAY  Box  AND  POST. 


BATTERY  CHUTE, RELAY 
Box  AND  POST  COMBINED. 


X 


NOTE  :  TYPE  OF  INDICATOR 

TO  BE  COVERED  BY 
GENERAL  NOTE  . 


SWITCH    Box  LOCATION  .        SWITCH   INDICATOR 


SWITCH  INDICATOR 
AND  SWITCH  Box. 


A 


0 


00 


00 


CABLE  POST     WITH  ONE      WITH  Two     WITH  RELAY     WITH  RELAY     WITH  RELAY 
ONLY.         INDICATOR.      INDICATORS.        Box.          Box  AND  ONE     Box  AND  Two 

INDICATOR.      INDICATORS. 


\ 


ABOVE  SURFACE. 


5  j-  HALF  ABOVE  SURFACE  . 


HIGHWAY  CROSSING  BELL. 


BELOW  SURFACE. 
(FIGURES  INDICATE  CAPACITY) 


>  BATTERY  SHELTER. 


OR 


B 


TRACK   BATTERY. 


Figs.   77-100.     Location  Symbols   (continued). 


STANDARD    SYMBOLS. 


Figs.  101-133 


INTERLOCKED  SWITCHES  AND  DERAILS. 


SWITCH -SET  FOR  TURN-OUT* 


DERAIL-  POINT  TYPE -DERAILING. 


SWITCH -SET  FOR  STRAIGHT  TRACK  . 


DERAIL-  POINT  TYPE-NON-DERAILING  . 


DERAIL  -  LIFTING  RAILTYPE -DERAILING  . 


DERAIL-  LIFTING  RAILTYPE-NON-DERAILING, 


DERAIL -LIFTING  BLOCK  TYPE-DERAILING.  DERAIL- LIFTING  BLOCKTYPE-NON-DERAILING. 

NOTE:  NON- INTERLOCKED    SWITCHES  AND  DERAILS  TO  BE  SHOWN 

SAME  AS  ABOVE  EXCEPT  SHADING  IN  TRIANGLES  OMITTED. 


RUNS 

OF  CONNECTIONS. 


PIPE-WIRE  (MECH.). 


WIRE  DUCT, 


COMPRESSED  AIR. 


PIPE-WIRE  AND  DUCT. 


PIPE- WIRE  AND  AIR 


DUCT  AND  AIR. 


PIPE -WIRE,  DUCT  AND  AIR 


MAN-HOLE. 


BOLT  LOCKS. 


COMPENSATOR. 


ARROW  INDICATES  DIRECTION 
OF  MOVEMENT  OF  PIPE  LINE 
NORMAL  TO  REVERSE. 


OIL  ENCLOSED  PIPE  LINE. 


BOLT  LOCKED  SWITCH.  3  WAY- 

S.L.M.= SWITCH  &  LOCK  MOVEMENT.        CRANKS . 
RRLf  FACING  POINT  LOCK.  I-WAY. 


2-WAY. 


3-WAY. 


TRACK 


INTERLOCKING  OR  BLOCK  STATION. 

SHOWING  RELATIVE  POSITION  OF  STATION, OPERATOR  AND  TRACK. 


OPERATOR  FACING  TRACK  .  OPERATOR  WITH  BACK  TO  TRACK. 

NOTE:  UNLESS  OTHERWISE  SPECIFIED  ON  PLAN  IT  WILL  BE  ASSUMED  THAT  WHERE  AN 

INTERLOCKED  SIGNAL  IS  SHOWN  CLEAR  OR  A  DERAIL  SHOWN   IN   NON-DERAILING 

POSITION  THE  CONTROLLING  LEVER  IS  REVERSED,  AND  THAT  ALL  OTHER  LEVERS  ARE  NORMAL. 


Figs.  101-133.     Location  Symbols   (continued). 


Pigs.   I34-J38 


STANDARD    SYMBOLS 


INTERLOCKED  SWITCHES,  DERAILS,  ETC 


DOUBLE  LINE  PLAN  . 


SINGLE  LINE  PLAN  . 
EXPLANATION 


1  -  SIMPLE  TURN-OUT. 

2  -  SIMPLE  CROSS-OVER. 

3  -  DERAIL -POINT  TYPE  . 
4- SINGLE  SLIP  SWITCH. 


5 -DOUBLE  SLIP  SWITCH. 
6 -MOVABLE  POINT  CROSSING  FROG.  (M.P.F.) 
7  — SINGLE  SLIP  SWITCH  WITH  M.P.F. 
8 -DOUBLE  SLIP  SWITCH  WITH  M.P.F. 


ROCKING  SHAFT  LEAD-OUT* 


4 

PIPE     LINE. 

t 

' 

WIRE    LINE. 

c 

[^)  WHEEL. 

1234       6789 

CRANK  LEAD-OUT. 


\ 

2  -WAY  CRANK/ 

X 

\ 

\ 

I-WAYC 

RANK. 

N4-WAY  CRANK. 

|_ 

1 

- 

4 

i 

i 

\ 

( 

' 

f 

5 

c 

! 

VERTICAL  CRANKS. 

DEFLECTING  BAR  LEAD-OUT. 


—  •- 

\ 

4 
> 

I 

> 

l               ( 

> 
( 

f 

l 
( 

•+  — 

•\ 

( 

/^H 
> 

( 
/ 

>  ( 
/ 

>    < 
/ 

1              ( 

»   < 
\ 

1   ( 
\ 

i 
\ 

HORIZONTAL  DEFLECTING  BARS, 


123  678 

VERTICAL    DEFLECTING    BARS. 


Figs.    134-138.      Location    Symbols    (continued). 


STANDARD    SYMBOLS. 


Figs.  139-157 


RELAYS,  INDICATORS  AND  LOCKS. 


ELEMENTS  OF  SYMBOLS 
TO  BE  COMBINED  AS 

NECESSARY. 


X 


T  -  -r  -r  —  T 

ill  I         ! 


D.  C.  ELECTRO  MAGNET. 

A.  C.  ELECTRO  MAGNET. 

COIL  ENERGIZED  OR  DE-ENERGIZED. 

NEUTRAL  FRONT  CONTACT  -  CLOSED  OR  OPEN  , 

NEUTRAL  BACK  CONTACT  -  CLOSED  OR  OPEN 

POLARIZED  ARMATURE  -  WITH  CONTACTS. 


3  -POSITION  ARMATURE  -WITH  CONTACTS. 


T--T 


___. 

1°     f    F 

T—  '"T  T""*T          T—     T 


II  II  I  |  II 

a---j_       a  —  JL        a  —  u       -L  —  i. 


HIGH  CURRENT  CONTACT 


MAGNETIC  BLOW-OUT  CONTACT 


BELL  ATTACHMENT. 


DOUBLE  WINDING  -SPECIFY  IF  DIFFERENTIAL 


SLOW  ACTING. 


Disc  TYPE  INDICATOR.  O=Disc  INVISIBLE.  0  =  0150  VISIBLE, 


tea 
SEMAPHORE  TYPE  INDICATOR,  r    =  3-PosmoN.. 


"rs~"T  "*•""" 

OR  ;Xii°R  iilLi       WIRE  WOUND  ROTOR. 


i-*-~jr 

!Xi  I  OR 


-- 

-o 


LflfifiJ 


STATIONARY  WINDINB.  /j 


= 


VOLTAGE  WINDING. 


J i.  -L J-  -L J_  J. i 


ELECTRIC  LOCK-  SHOW  SEGMENTS  FOR  LEVER  IN  NORMAL 
POSITION  . 

(SEE  NEXT  PAGE  FOR  EXAMPLES  OF  COMBINATIONS.) 


Figs.  139-157.     Symbols  for  Circuit  Plans. 


Figs.  158-168 


STANDARD    SYMBOLS. 


RELAYS  ,  INDICATORS  AND  LOCKS. 

EXAMPLES    OF    COMBINATIONS  . 

D.C.  RELAY-  NEUTRAL-  ENERGIZED  - 

ONE  INDEPENDENT  FRONT  CONTACT  CLOSED  - 
ONE  INDEPENDENT  BACK  CONTACT  OPEN  . 

D.C.RELAY- POLARIZED- ENERGIZED  - 

Two  COMBINATION  FRONT  AND  BACK  NEUTRAL  CONTACTS 
Two  POLARIZED  CONTACTS  CLOSED  - 
Two  POLARIZED  CONTACTS   OPEN. 


-o 


D.C.  INDICATOR-  SEMAPHORE  TYPE- ENERGIZED  - 
THREE  FRONT  CONTACTS  CLOSED  — 
BELL  ATTACHMENT  . 

D.G.  INDICATOR  -  SEMAPHORE  TYPE  -  ARM  HORIZONTAL  - 

ENERGIZED- WITHOUT  CONTACTS. 
NOTE  :  INDICATORS  (OR  REPEATERS)  WITHOUT  CONTACTS  SHOULD  BE  SHOWN 

WITH  ARMATURES  TO  INDICATE  WHETHER  ENERGIZED  OR  DE-ENER- 
GIZED . 

A. C. RELAY- ONE  ENERGIZING  CIRCUIT  TYPE  (SINGLE  PHASE) 
ENERGIZED -ONE  FRONT  CONTACT. 


A. C. RELAY- Two  ENERGIZING  CIRCUIT  TYPE- ENERGIZED 
WIRE  WOUND  ROTOR  — 
Two  NEUTRAL  FRONT  CONTACTS  . 


A. C.  RELAY-Two  ENERGIZING  CIRCUIT  TYPE- ENERGIZED  — 
WIRE  WOUND  ROTOR  — 
Two  POLARIZED  CONTACTS. 

A.C  RELAY-Two  ENERGIZING  CIRCUIT  TYPE -ENERGIZED 
STATIONARY  WINDINGS  — 
ONE  NEUTRAL  FRONT  CONTACT  — 
Two  3- POSITION  CONTACTS. 

D.C.  INTERLOCKED   RELAY. 


D.C.  ELECTRIC   BELL. 


DESIGNATE    RESISTANCE  IN   OHMS  OF  ALL    D.C. RELAYS,  INDICATORS   AND    LOCKS 


-Or 


JJ. 


JJ. 

t     t 


Figs.    158-168.     Symbols   for    Circuit    Plans    (continued). 


IO 


STANDARD    SYMBOLS. 


Figs.  169-170 


CIRCUIT  CONTROLLERS  OPERATED  BY  LEVERS  . 

USE  EITHER  LETTER  SYSTEM  OR  GRAPHIC  SYSTEM  . 


LEVERS  WITH  EXTREME  END  POSITION  AS  NORMAL  . 

N-FULL  NORMAL  POSITION  OF  LEVER. 
B -NORMAL  INDICATION  POSITION. 
C- CENTRAL  POSITION. 
D-REVERSE  INDICATION  POSITION.      r 
R-FULL  REVERSE  POSITION. 


LETTER 
SYMBOL. 


GRAPHIC 
SYMBOL 


i^ 


^ 


LEVERS  WITH  MIDDLE  POSITION  AS  NORMAL  . 

N- NORMAL  POSITION. 
L-FULL  REVERSE  POSITION  TO  THE  LEFT. 
B-INDICATION  POSITION  TO  THE  LEFT. 
D -INDICATION  POSITION  TO  THE  RIGHT. 
R-FULL  REVERSE  POSITION  TO  THE  RIGHT. 


LETTER 
SYMBOL . 

L 


B      N      D 


GRAPHIC 
SYMBOL. 


+ 


NOTE:  HEAVY  HORIZONTAL  LINES  INDICATE  PORTION  OF  CYCLE  OF  LEVER  THROUGH  WHICH  CJRCUIT  is  CLOSED, 


Figs.    169-170.     Symbols  for   Circuit  Plans    (continued). 


Figs.  171-181 


STANDARD    SYMBOLS. 


ii 


CIRCUIT  CONTROLLERS  OPERATED  BY  SIGNALS 

UPPER  QUADRANT.  LOWER  QUADRANT. 


3  -POSITION 
SIGNALS. 


AT  0   ONLY. 


AT  45 


^       g        CLOSED  AT  90  ONLY. 


a 


\ 


CLOSED  0  TO 


60-70  OR 
75°  SIGNALS. 


AT 


CLOSED  IN  ULEAR 
POSITION  ONLY. 


* — * 


«       t 


•       » 


*7 


•       • 


•       t 


CLOSED. 


OPEN.- 


^    • 
•    1 


CIRCUIT  CONTROLLER  OPERATED  BY  LOCKING 


SWITCH    CIRCUIT    CONTROLLER.          MECHANISM  OF  A  SWITCH  MOVEMENT. 


>-* 


CLOSED 
OPEN. 


BRIDGE   CIRCUIT    CONTROLLER. 


POLE  CHANGING  CIRCUIT  CONTROLLER. 

,    u 
t 

SPRING  HAND  KEY  OR  PUSH  BUTTON. 


CIRCUIT  SWITCH. 


Figs.    171-181.     Symbols    for    Circuit    Plans    (continued). 


12 


STANDARD    SYMBOLS. 


Figs.  182-200 


MANUAL  TIME  RELEASE, 
(ELECTRIC) 


AUTOMATIC  TIME  RELEASE. 
(ELECTRIC) 


fr 


MANUAL  TIME  RELEASE 
(ELECTRO -MECHAN'L.) 


EMERGENCY  RELEASE 
(ELECTRIC) 


FLOOR  PUSH. 


OPEN.  CLOSED. 

LATCH  CONTACT.       TRACK  INSTRUMENT  CONTACT, 


KNIFE   SWITCHES  . 


RHEOSTAT. 


()   () 

(b   d) 

SINGLE  POLE.  DOUBLE  POLE. 
SINGLE  THROW. 


()   () 
6  d) 

0  00 

SINGLE  POLE.    DOUBLE  POLE 
DOUBLE  THROW. 


QUICK  ACTING  CIRCUIT  CONTROLLERS  MAY  BE  DISTINGUISHED  BY  THE  LETTER 


FIXED  RESISTANCE. 


VARIABLE  RESISTANCE. 


FUSE  . 


IMPEDANCE    WITHOUT 
IRON  CORE. 


IMPEDANCE    WITH 
IRON  CORE. 


CONDENSER 


Figs.    182-200.     Symbols    for   Circuit    Plans    (continued). 


Figs.  201-224 


STANDARD    SYMBOLS. 


BATTERY. 

MUM 

CELLS  IN  MULTIPLE.  CELLS  IN  SERIES. 

SPECIFY  TYPE  AND  NUMBER  OF  CELLS  . 

D  =  DRY    BATTERY, 
G  =  GRAVITY  " 
P  =  POTASH    » 
5  =  STORAGE  » 

EXAMPLES:  I6P,  IOS,ETC. 


A.C.TERMINALS, 


D.C.TERMINALS. 


RECTIFIER. 


rw\  n^n 


I-  SECONDARY.  2-  OR  MORE  SECONDARIES. 

TRANSFORMERS. 


D.C.MOTOR. 


D.G.GENERATOR 


sm/ 

* — • 

A.C.  MOTOR, 


AMMETER  . 


A.C.  GENERATOR.  D.C.-D.C.  MOTOR-GENERATOR.     A.C.- D.C.MOTOR- GENERATOR 


INCANDESCENT  LAMP, 


WIRES  CROSS  . 


WATTMETER.         TELEPHONE 


A.  W 

SINGLE.  DOUBLE 

LIGHTNING  ARRESTER.  TERMINALS. 


j i 


WIRES  JOIN. 


GROUND 


"COMMON  "  WIRE. 


OTHER  THAN  "  COMMON"WIRE 


TRACK  CIRCUIT  WIRE. 


DIRECTION  OF  CURRENT 


Figs.   201-224.     Symbols   for   Circuit   Plars    (continued). 


SIGNAL  INDICATIONS. 


Figs.  225-235 


SEMAPHORE,  BLOCK 


Fig.   225.     Square    End   Semaphore    Blade.      Used   for       Fig.    226.      Notched    or    Fish    Tail    Semaphore    Blade. 
Block  and  Interlocking  Home  Signals.  Used  for  Block  and  Interlocking  Distant  Signals. 


Fig.    227.      Pointed    End    Semaphore    Blade.      Usually 

Used  for  Automatic  Home  Block  Signals,  or 

for   Train   Order   Signals. 


Fig.    228.      Round    End    Semaphore    Blade.      Used    for 
Train  Order  Signal,  or  Block  Signal,  or  for  Inter- 
locking Signals  Under   Special  Rules. 


Stop,  Block  Occupied. 


Proceed,    Block       Caution,     P  r  e- 
Clear.  pare      to      Stop 

at    Next    Home 
Signal. 


Clear,    Next    Home 

Signal     at    Proceed, 

Block    in     Advance 

Clear. 


Figs.  229-230.     Semaphore  Home   Block  Signals,  Two      Figs.  231-232.     Semaphore  Distant  Block  Signals,  Two- 
Position.  Position. 


Stop,  Next  Home  Signal  at  Stop.          Proceed,     Next    Home    Signal     at          Proceed,     Next    Home     Signal    at 

Stop.  Clear. 

Figs.  233-235.     Semaphore  Home  and   Distant  Block  Signals  on  Same  Post. 


Figs.  236-249 


SIGNAL  INDICATIONS. 


Stop,    Block    Occupied.  Caution,  Block  Clear,  Next  Signal          Clear,     Block     Unoccupied,     Next 

rt   Stop.  Signal  at  Clear  or  Caution. 

Figs.    236-238.      Three-Position    Semaphore    Block    Signal.    Lower  Quadrant  Indications. 


Figs.  239-241.     Three-Position   Semaphore  Block  Signal,  Upper  Quadrant    Indication.     The  Indications   Are  the 
Same   as   the  Corresponding   Lower   Quadrant   Indications  Shown  in  Figs.  236-238. 

DISK,  BLOCK 


Stop.  Proceed. 

Figs.  242-243.     Disk  Home  Block  Signal. 


Caution.  Clear. 

Figs.  244-245.     Disk  Distant  Block  Signal. 


Figs.    246-247. 
Disk    Home 
and    Distant 
Signal    on 
Same   post. 
The  Red  Indi- 
cates Stop,  the 
Green  Indicates 
Be  Prepared  to 
Stop  at   Next 
Signal  in 
Advance. 


Clear. 

Figs.  248-249.  Chi- 
cago &  North-Western 
Two-Light  Disk  Dis- 
tant Block  Signal.  The 
Red  Light  Is  Obscured 
When  the  Signal  Indi- 
cates Clear. 


i6 


SIGNAL  INDICATIONS. 


Figs.  250-259 


SEMAPHORE,  INTERLOCKING 


Stop. 


m 

? 

*~  -v 

an         < 

Proceed.       1 — 


Caution. 


Clear,  Next  Home 
Signal  at  Proceed. 


Figs.  250-251.    One-Arm  Semaphore  Interlocking  Home       Figs.      252-253.        One-Arm     Semaphore      Interlockin; 
Signal.  Distant   Signal. 


Stop,      no      Route      Is 
Clear. 


Proceed,     High     Speed 
Route    Clear. 


Figs.    254-256.      Two-Arm    Semaphore   Interlocking   Home   Signals. 


Proceed,      Infe- 
rior or  Low 
Speed    Route 
Clear. 


1     Caution,     Both     Corre- 
sponding Home  Sig- 
nals at  Stop. 


I 


Clear,  Home  Signal  for 

Main    Route    at 

Proceed. 


Figs.  257-259.     Two-Arm  Semaphore  Interlocking   Distant   Signals. 


Clear.    Home 

Signal    for 

Inferior  Route 

at  Proceed. 


Figs.  260-264 


SIGNAL  INDICATIONS. 


t<W      \ 

O, 


D 


,C 


Q 


Stop.      No    Route 
Clear. 


Proceed,      High- 
Speed   Route 
Clear. 


Proceed.     Medium 

Speed    Route 

Clear. 


Figs.  260-263.     Three-Arm  Semaphore 
Interlocking  Home  Signals. 


P  r  o  c  e  ed, 
Low  Speed 
I  n  f  e  r  i  or 

Route 

Clear. 


Fig.    264.      Five-Arm    Semaphore    Inter- 
locking Signal,  with  Home  and  Dis- 
tant Arms;  Indicating  Proceed 
over    High    Speed    Route. 

The  three  home  signal  arms  correspond  with 
the  three  home  signal  arms  shown  In  Figs. 
260-263.  Each  distant  signal  arm  gives  Indi- 
cation for  the  next  home  signal  on  the  same 
route  as  that  for  which  the  home  arm  Imme- 
diately above  it  indicates. 


i8 


SIGNAL  INDICATIONS. 


Figs.  265-284 


r 

R 

=1            < 

3=1                 R 

«^      * 

1  1                 R 

Jl 

^   "~>                C 

o=n             R 
^           w 

o=r,                    n 

Jl           - 

r^1         c 

=1                               RO 

a? 

=l                   Ro 

J 

=1                   Wo 

K 

0 

0  10  11  12 

Numbers  1  to  8,  inclusive,  are  Class  "A,"  "Stop  and  Stay." 
The  first  five  show  indications  for  high  and  moderate  speeds, 
and  the  other  three  show  indications  for  low  speeds,  as  fol- 
lows :  1 — Stop  and  stay  ;  2 — Proceed  with  caution  to  next  sig- 
nal, on  high-speed  track  ;  3 — Proceed  at  high  speed,  on  high-speed 
track ;  4 — Proceed  with  caution  to  next  signal,  on  moderate 
speed  track  ;  5 — Proceed  at  moderate  speed,  on  moderate-speed 
track  ;  6 — Stop  and  stay ;  7 — Proceed  with  caution,  on  low-speed 
track  ;  8 — Proceed  at  low  speed,  on  low-speed  track.  The  lights 
0re  in  a  vertical  line. 

Numbers  9  to  12,  inclusive,  are  Class  "B,"  "Stop,  Wait  Time 

yj  pj  "fP  and  Proceed"  signals.  These  are  for  the  automatic  system  and 

also  for  distant  signals  when  the  latter  are  used  to  give  an 
independent  indication  ;  9 — Indicates  stop,  and  proceed  after 
waiting  time;  10 — Proceed  to  next  signal,  prepared  to  stop; 
11 — Proceed  at  full  speed,  next  high  speed  signal  at  caution  or 
6  I  clear  ;  12 — Proceed  at  moderate  speed  ;  next  moderate-speed  sig- 

nal at  caution  or  clear.  The  lower  light  is  staggered  to  the  left. 

In  all  the  figures  R  indicates  a  red  light ;  G,  green  ;  W, 
white. 

Figs.  265-276.     Three-Position  Upper    Quadrant    Block  and    Interlocking    Signals,    with    Two    High    Arms,    as 
Installed   on   the    Central    Division   of   the    Philadelphia,    Baltimore  &  Washington  Railroad. 


SIGNAL  LOCATIONS  WITH  REFERENCE  TO  TRACKS  GOVERNED 


'.  Main 
.Main 


,Ma/'rr 


".Main 


Double  Track. 


Three  Tracks.     Middle  Track  Not 
Signaled. 


Four   Tracks.      Only   the   Two 
Outside  Tracks  Signaled. 


Two   Home  and  One  Distant  Sig- 
nal   on    Same    Post. 

Upper  home  governs  direct  route.  Dis- 
tant indicates  position  of  home  signal 
at  crossing  and  lower  home  governs  di- 
verging route. 


Trailing    Point    Crossover. 

High  signals  govern  main  track 
movements  in  direction  of  arrows.  Dwarf 
signals  govern  crossover  and  main  track 
reverse  movements.  Signals  and  switches 
worked  in  conjunction  with  each  other. 


Facing  Point  Crossover. 

Top  arms  of  high  signals  govern  mala 
line  movements  in  direction  of  arrows. 
Lower  arms  govern  crossover  move- 
ments. Dwarf  signals  govern  reverse 
movements. 


U^^^fc-         .    "•  Main 

^^"-^      1  '••'r/"rrr 

Trailing  Point  Siding  Switch. 

High  signal  at  clear  indicates  switch  set  for  main  track 
in  direction  of  arrow  ;  at  stop  indicates  switch  may  be  set  for 
siding.  Dwarf  signals  govern  movements  into  or  out  of  siding, 
and  reverse  movements  on  main  track. 


/v-y 


Diverging   Routes. 


Upper  arm  governs  movements  over  the  main  route,  middle 
arm  over  the  next  inferior  route  and  lower  arm  over  least  im- 
portant route,  and  may  be  made  to  indicate  for  any  number  of 
low-speed  routes  inferior  to  that  governed  by  the  middle  arm. 


Figs.  277-284.     Ground    Post  Signals. 


Figs.  285-296 


SIGNAL  INDICATIONS. 


I 


'.Main 


Double    Track. 


'.Mar/rr 


T 


Three   Tracks.      Middle   Track 
Not  Signaled. 


Three  Tracks.     One  Outside  Track 
Not  Signaled. 


Pass 


Pass. 


|Q 


7'hree  Tracks.     Low  Arm  for  Low 
Speed  Track  in  Center. 


Three  Tracks.     Low  Arm  for  Low 
Speed   Track   on    Outside. 


Four  Tracks.     Upper  Two  Tracks 
Not  Signaled. 


Main 


Ma/n 


Four  Tracks.     Two  Middle  Tracks 

Only,     Signaled.       Dummy 

for    Outside    Track. 


Four  Tracks.     Two  Middle  Tracks 

Only,  Signaled.     Dummies 

for   Outside  Tracks. 


Four     Tracks. 
Signaled. 


Alternate     Tracks 
One  Dummy. 


I 


I 


\Mail-i 


:/=/-/. 


Four  Tracks  Signaled.    Low  Arms 
Indicating  Low  Speed  Move- 
ments on   Outside  Tracks. 


Four  Tracks  Signaled. 


Four  Tracks  Signaled.     Low  Arms 
Indicating  Low  Speed  Move- 
ments on  Middle  Tracks. 


Figs.  285-296.     Bracket  Post  Signals. 


20 


SIGNAL  INDICATIONS. 


Figs.  297-307 


.tfar&s. 


I 


Ground      Post     Signal     for     High 

Speed      Track      on      Outside; 

Bracket  Post  with  Low  Arm 

for  Middle  Track  Used  for 

Low  Speed   Movements, 

and     High    Arm    for 

Outside  Track. 


'.Main 
'.Main 


Ground     Post     Signal     for     High 

Speed,-  Track      on       Outside; 

Bracket  Post,  with  High  Arm 

for    Middle    Track,    and 

Lower  Arm  for  Freight 

or  Low-Speed  Track 

on    Outside. 


Ground    Post    Signal   and    Bracket 
Post    Signal    for    Outside    and 
Middle     Track.      Dummy 
on  Bracket  Post  to  In- 
dicate Other  Outside 
Track    is    Not 
Signaled. 


^ 


~.LowSf>aed 
'.High  5/>e»c/ 


II 

Crossover  from  High  Speed  Track 
to  Low   Speed  Track. 

The  single  arm  is  for  low-speed 
track,  there  being  but  one  possible 
normal  movement  on  that  track.  The 
double  arm  high  signal  governs  the 
high  speed  track,  the  top  arm  for 
straight  movements  and  the  lower  arm 
for  crossover  movements.  The  dwarf 
signals  govern  reverse  movements. 


Figs.  297-300.     Ground  Post  and  Bracket  Post  Signals. 


Pass. 


Signals  for  Both   Tracks   Mounted 
on  Bridge  Over  Tracks. 


Pa*s. 


Three   Tracks.     Low   Signals   For 

Low  Speed  Track  in 

Center. 


Four  Tracks  Signaled.     All  Signals   Mounted  on   Bridges.     Low  Signals  for 
Low-speed  Tracks.     Three  Different  Arrangements  of  Tracks. 

Figs.  301-305.     Bridge   Signals. 


I 


I 


'.Main 
'.Siding 


'.  Siding 
'  Main 

Branch 


Diverging  Routes.  One    Main    and    Two    Diverging    Routes. 

Figs.  306-307.     Typical   British  Arrangement   of  Signals. 


A   bracket  post  is   used,   having  a  doll   for   each  arm ;   the   arm    governing   movements    over    the    main    route    Is    mounted 
higher   than    other  arms.      An   arm   governing  diverging   movements  is  placed  on  the  corresponding  side  of  the  main  route  arm. 


BLOCK  SIGNALS  21 


BLOCK  SIGNALS 
Pages  22-132         Figures  308-739 


Pages 

Figures 

TYPICAL  ARRANGEMENTS       

....       22-23 

308-324 

MANUAL        

....       24-27 

325-345 

COMMUNICATING  MECHANISMS    

....             24 

325-327 

LEADOUTS      

....       24-25 

328-338 

ENGLISH  PRACTICE  IN  MANUAL  SIGNALS      .... 

....       25-27 

339-345 

CONTROLLED  MANUAL    

....        27-45 

346-405 

AUTOMATIC     

....        46-93 

406-615 

THE  TRACK  CIRCUIT       

....        46-55 

406-483 

CONTROL  CIRCUITS     

....        55-64 

484-511 

MECHANISMS       

....        64-90 

512-602 

ALTERNATING  CURRENT  SIGNALING         

....        91-93 

603-613 

SIGNALS  FOR  ELECTRIC  RAILWAYS       .... 

.    .    .    .        94-125 

614-713 

SYSTEMS          

.    .    .    .        94-103 

614-636 

INSTALLATIONS       

.    .    .    .      104-125 

637-713 

SELECTIVE  SIGNALING  FOR  STEAM  AND  ELECTRIC 

ROADS  126-132        714-739 


22  BLOCK    SIGNALS.  Figs.  308-313 

TYPICAL  ARRANGEMENTS 


Fig.  308.     Block  A   to  B.     Train  in   Block.     Protected  by  Signal  A  in  rear,  Indicating  Stop  to  Following  Train. 


I 


Fig.  309.     Blocks  A  to  B,  and  B  to  C.     Train  Has  Just  Passed  Signal   C.     Signal  B  is  Clear  for  Next  Train  to 

Pass  B  Toward  C. 


H  2  D2  H  1  D  1 


Fig.  310.     Home  and  Distant  Block  Signals.     Block  Hi   to   H2.     Distant   Signals  Di    and   D2   Give   Preliminary 
Information    as    to    Indication    at    Next    Home   Signal.     Train   in    Block.     Hi    and    Di    Indicate 
Stop  and  Caution  Respectively,  Protecting   Following   Train. 


lit 


<%; 


Fip.  311.     Home   and  Distant   Signals.     Distant   Signal  Mounted  on  Same  Post  with  Home  Signal  in  the  Rear. 


Fig.  312.     Block  Signals  With  Overlap.     Block  A  to  B.     Signal  A  Indicating  "Stop"  Behind  a  Train  Cannot  be 
Cleared    Until    That    Train    Has    Passed    Beyond    the  Overlap. 


L        JL 


1 — •         '    •  ' — •          i     •  i — •          i    • 

I       Bl  I       IOI  I       Ql 


B 

1^ /to  /Or77//es -H 

Fig.  313.     Manual  Block  Signals  on  Double   Track  Railway.     Blocks  A  to  B  and  B  to  .C.     Signalmen  Stationed 

in  Cabins  Communicate  by  Telegraph,  Telephone   or    Bell,    Ascertaining    if    Block   Ahead    is    Clear 

Before    Allowing    Train    to    Pass    by    Setting  Home  and   Distant  Signals  at   Clear. 


Figs.  314-324 


BLOCK    SIGNALS. 


VUssf 


East 


'Fig.  314.     Middle   Passing  Track  at  Manual    Block   Stations  on  Erie  Railroad. 

Switches  near  cabin  operated  by  levers  in  cabin  interlocked  with    signal    levers ;    outlying    switches    have    electric   locks   con- 
trolled from  cabin.     Passing  track  about  8,000  ft.  long. 


West 


V///////P 


Fig.  315.     Three-Position  Arm  for  Permissive  Blocking  on   Single  Track   Roads.     Signal   A   Indicates  Caution; 

Signal  B,  Clear;  Signal  C,  Stop. 


Home    Signals    for   East   and    West   Movements 
on    Same   Post   at   Station. 


Home    Signals   on    Separate    Posts    Beyond 
Station. 


Figs.   316-317.     Manual   Block    Station   on   Single   Track  Roads.      Switches    Not    Controlled    from    the    Station. 

Many  such  stations  have  no  distant  signals. 


h 


j— sojo'-H 


FIG 


J^ 


Fig.    318.      Distant,    Home,    and    Advance    Signals    at 
Manual   Block   Station. 

Where  the  home  signal  is  at  or  near  a  station  platform  a 
train  may  be  allowed  to  pass  the  home  signal,  but  be  held  at 
the  advance  signal  until  the  block  ahead  is  clear.  In  effect  a 
short  intermediate  block  is  formed,  in  which  a  train  may  be 
held  without  delaying  a  following  train  entering  the  block  at 
the  next  block  station  in  the  rear. 


V 


Figs.    319-323.     Northern    Pacific    Scheme    of    Auto- 
matic   Signaling   on    Single    Track. 


lit 


lit 


<y/////A 


L— o^/ap—  --^= 


Fig.    324.     Automatic    Block    Signals    With    Overlap    in    New  York  City  Subway. 

The  overlap  is  made  the  length  of  a  block  and  the  blocks  asshort   as   possible.      (About   25  per  cent,   longer  than  the  distance 
required  for  an   emergency  stop  for  trains  running  at  maximum   speed.)     Automatic  train  stops  are  used  at  each  home  signal.     A 
train   is  always  protected  by  two   home  signals   indicating  stop   behind    it    and   by    a   distant  signal    indicating   caution   one   t 
behind    the    second   home   signal.      The    distance   between    trains    running  at  full  speed  must  be  more  than   three  blocks. 


BLOCK    SIGNALS. 


Figs.  325-331 


MANUAL 


COMMUNICATING    MECHANISMS 

-Q    & 


a     a- 


Fig.  325.     Morse   Telegraph    Circuits    Between    Block    Stations,  with    Line  Battery  at  Alternate  Stations. 

To  spare  Strap  in 


LAJ 


Fig.    326.     Morse    Telegraph    Circuits    Between    Block  Stations,  with  Line  Battery  at  Each  Station. 
NOTE. — When  line  is  more  than  20  miles  long,  relays  working  sounders  on  local  circuit  must  be  used  in  either  arrangement  shown. 


O 


O 


^  — •_     V 


B 


H 


Fig.    327.     Communicating    Bell     Circuits    for    Manual  Block   Stations;   Erie   Railroad. 

A  presses  key  f  which  closes  circuit  from  battery  X  at  A  through  contact  of  key  f  (now  closed),  line,  normally  closed  con- 
tact of  key  e  at  B,  wire  2,  bell  F  to  ground  G.  When  B  presses  key  e,  bell  E  at  A  rings  through  similar  circuit.  Each  station 
has  bell  and  key  for  eastbound  and  westbound  communication. 


LEADOUTS 


Figs.    328-329.      Signal    Levers. — Two    Lever,    Two- 
Position    Wall    or    Table    Lever    Machine 
with  Chain  Wheel  Attachment.     The 
Union  Switch  &  Signal  Company. 


Figs.    330-331.      Signal    Levers. — Two    Lever,    Two- 
Position  Table  Lever  Machine  for  Vertical  or 
Horizontal   Pipe   or   Wire   Leadout.    The 
Union   Switch    &   Signal   Company. 


Figs.  332-340 


BLOCK    SIGNALS. 


25 


Figs.  332-333-  Two-Lever  Two- 
Position  Table  Lever  Machine  for 
Horizontal  Pipe  or  Wire  Leadout. 
The  Union  Switch  &  Signal  Co. 


.... 

Vertical  and  Horizontal 

piPe    Leadouts    for    Table 
Machines. 


Chain  Wheel  and  Wire 
Leadouts  for  Wall  and 
Table  Machines. 


Vertical  and  Hori- 
zontal Wire  Lead- 
outs for  Wall  and 
Table  Machines. 


Figs.  334-335-     Three-Position   Horizontal  Wall  Lever 
Machine  for  Vertical  Lead-out.     The  Union 
Switch   &  Signal   Co. 


Figs.    336-338.     Leadout    Connections    from    Manual    Block 
Stations   to    Signals. 


HORIZONTAL    WALL    LEVER    MACHINE. 

The  pendulum  P  lies  normally  ia  the  vertical  plane  as  shown 
in  Fig.  335.  When  the  signal  lever  is  returned  from  its  lowest 
or  clear  position,  its  latch  impinges  on  the  lower  side  of  the 
lug  1,  rotating  it  around  the  pivot  p,  and  past  the  center  notch 
r,  thus  preventing  the  lever  latch  from  falling  into  the  notch. 
This  compels  the  signalman  to  complete  the  travel  of  the  lever 
and  thus  return  the  signal  to  "stop"  before  again  clearing  it. 
As  soon  as  the  lever  has  passed  the  center  notch,  the  pendulum 
P  falls  back  to  its  normal  position  by  gravity. 


ENGLISH  PRACTICE  IN  MANUAL  SIGNALS 


The  usual  telephone  instruments  are  installed  in  each  block 
station,  being  connected  across  a  pair  of  continuous  line  wires 
as  shown  in  Fig.  342.  A  common  ringing  battery  is  installed 
at  one  station  which  supplies  current  when  required  for  ener- 
gizing the  relays,  A,  used  to  cut  in  the  call  bells  operated  from 
local  battery.  In  order  to  economize  ringing  battery  current 
and  to  cut  down  noise  on  the  line  from  induced  current  an  ar- 
rangement of  impedance  coil  and  cutting-out  relay  is  used  with 
the  ringing  battery.  The  operation  of  this  device  is  shown  in 
Figs.  339-340.  The  battery  is  connected  to  ground  on  one  side 
and  through  the  relay  on  the  other  side  to  the  center  of  the 
impedance  coil.  This  coil  is  connected  across  the  line  wires, 
direct  on  one  side  and  through  a  back  contact  of  the  cutting- 
out  relay  on  the  other  side.  When  any  ringing  key  is  closed, 
as  at  2,  Fig.  340,  a  path  is  closed  to  ground  from  the  lower 
line  wire.  Current  flows  from  ringing  battery  on  upper  line 
wire  through  all  the  bell  relays  A,  except  that  at  2,  across  the 
line  and  through  lower  line  wire  toward  2,  where  connection  is 
made  with  ground.  No  current  flows  direct  from  battery  to 
ground  over  lower  line  wire,  because  the  cutting-out  relay  Is 
energized  by  the  current  flowing  through  the  upper  line  wire 


and  opens  the  back  contact  to  lower  line  wire.  All  of  the 
bell  relays  A,  except  that  at  2,  are  energized  and  the  bells 
ring  simultaneously,  the  circuit  being  from  local  battery 


Figs.    339-340.      Method    of    Operation    of    Telephone 
Ringing  Key. 

through  the  bell,  closed  on  relay  A,  ringing  key  terminal,  back 
to  battery.  As  soon  as  the  ringing  key  at  2  is  opened  again, 
the  path  to  ground  is  broken,  all  bell  relays  A  are  de-energized. 


26 


Figs.  341-344 


BLOCKSIGNALS. 


TAPPER  Disc 

Fig.  341.     Indicator  Block  Instrument,  Great  Western 
Railway  of  England. 


o 


o 


—  j—  <i>     VSMi"  -t?     W     icj-          .  —|i" 

—  <S 

)    ®    d 

^ 

Common  R/ng/'ng 
--Bcrffe.iy. 

•)     <5n»^ 

E       <A>        W  1"' 

y  •  Loccr/ 

Tjg?y 

— 

~=~^ 

"  7r~ar?5/77/ffe/- 

~^~ 

Fig.    342.     Telephone    Communicating   Circuits    Between  Block    Stations,    Great    Western    Railway    of    England. 


Instrument   Open.  Instrument   Closed. 

Figs.  343-344.     Repeating  Block   Instrument,   Lancashire  &  Yorkshire  Railway. 


Figs.  345-347 


BLOCK    SIGNALS. 


27 


Fig.  345.     Single   Needle   Block  Instrument,   Great 
Western    Railway   of    England. 


the  bells  cease  ringing,  and  the  cutting-out  relay  drops  to  its 
normal  position,  ns  shown  in  Fig.  339.  The  impedance  across 
the  line  at  the  ringing  battery  permits  induced  currents  to  pass 
equally  from  each  line  to  ground,  and  prevents  noise  on  the 
telephone  circuit.  The  bell  relays  A  are  of  high  resistance 
and  are  not  affected  by  the  current  flowing  on  the  telephone 
circuit. 

The  block  instrument  commonly  used  in  Great  Britain  for 
communicating  between  block  stations  is  essentially  a  galva- 
nometer, having  a  rotating  armature  mounted  between  two  coils 
of  wire.  When  current  flows  through  the  coils  in  one  direction 
the  armature  tends  to  rotate  to  the  right  and  when  the  direction' 
of  flow  of  current  is  reversed  the  armature  rotates  to  the  left. 
When  no  current  flows,  the  armature  returns  to  a  neutral  po- 
sition in  the  center.  The  armature  may  carry  a  printed  disk 
or  indicator  as  in  Fig.  341,  or  simply  a  needle,  as  in  Figs.  341 
and  345.  The  needle  instrument  (Fig.  345)  may  be  used  as  a 
speaking  telegraph  also,  movements  of  the  needle  to  the  right  or 
left  corresponding  to  the  dots  and  dashes  of  the  Morse  code. 
Sending  is  done  by  pressing  down  the  "line  clear"  key  or  the 
"train  on  line"  key  (Fig.  341),  or  by  turning  the  knob  (Fig. 
344)  to  the  right  or  left.  This  reverses  the  polarity  of  the 
current  by  changing  the  connections  of  the  battery  between 
line  and  ground. 

When  a  signalman,  say  at  B,  gives  a  "line  clear"  signal  to 
the  station  in  the  rear,  say  A,  he  fastens  his  indicator  in  the 
"line  clear"  position,  thus  keeping  before  him  a  visual  indica- 
tion of  what  he  has  done.  As  soon  as  the  station  in  the  rear 
(A)  reports  the  starting  of  the  train,  the  signalman  at  B 
puts  his  indicator  in  the  position  showing  "train  on  line"  and 
fastens  it  there.  In  like  manner  the  signalman  at  B  fastens 
his  indicator,  after  sending  any  signal  over  the  wire  to  C,  thus 
having  before  him  constantly  a  visual  indication  of  the 
movement  last  made. 


CONTROLLED  MANUAL 


U.    S.    &    S.    ELECTRO-MANUAL    SYSTEM. 

The  principle  on  which  all  controlled  manual  block  systems 
are  operated  is  that  before  any  signal  can  be  displayed  to  admit 
a  train  into  a  block,  the  co-operation  of  two  persons,  one  lo- 
cated at  each  end  of  the  block,  is  necessary.  This  result  is  ob- 
tained by  electrically  controlling  the  levers  operating  the  block 
signals:  the  electric  control  being  so  devised  that  each  signal- 
111:111  must  perform  certain  prescribed  manipulations  before  any 


signal  can  be  cleared  by  the  signalman  at  either  end  of  the  block. 
In  the  Union  electro-manual  system,  the  operating  levers  and 
the  mechanical  and  electric  devices  which  control  them  are  com- 
bined in  one  compact  instrument,  views  of  which  are  shown  in 
Figs.  346-347.  The  instrument  is  secured  to  the  wall  of  the 
office  in  which  it  is  located  and  the  mechanical  connections  be- 
tween it  and  the  signals  it  operates  are  attached  to  one  or  the 
other  end  of  the  racks  operated  by  the  levers. 


Figs.    346-347.     Union     Electro-Manual     Block     Instrument. 


28 


BLOCK    SIGNALS. 


Figs.  348-351 


The  Instrument  shown  is  such  as  is  used  at  intermediate 
block  stations  and  consists  of  two  complete  and  independent 
levers,  their  controlling  devices  and  indicators.  The  lever  and 
its  controlling  devices  located  on  the  right  of  the  instrument 
govern  the  block  to  the  left,  and  the  lever  on  the  left  governs 
the  block  to  the  right. 

Both  the  mechanical  and  electric  locking  of  the  instrument 
is  applied  to  the  latch  instead  of  the  lever  as  is  ordinarily  the 
case,  thus  greatly  minimizing  the  strain  which  it  is  possible  to 
apply  to  such  locking  and  furthermore  insuring  that  the  locking 
is  operated  before  any  movement  can  be  given  to  the  lever. 

The  operating  lever  can  be  returned  to  the  normal  position 
directly  from  any  other  position. 

The  instrument  can  be  used  with  or  without  track  circuit 
control;  in  other  words,  if  originally  installed  without  the  use 
of  track  circuits,  these  can  be  added  later  by  simply  ^modifying 
the  external  wiring,  no  changes  being  necessary  in  the  instru- 
ments themselves. 

A  combined  plunger  and  push  button  is  provided  for  trans- 
mitting bell  signals  for  giving  a  release  to  the  signalman  at  the 
opposite  end  of  the  block. 

When  a  signalman  at  one  end  of  the  block  has  given  a  release 
to  a  signalman  at  the  opposite  end,  the  former  cannot  take  it 
away  again  without  the  consent  of  the  latter,  although  the 
signalman  receiving  the  release  might  not  have  used  it  to  clear 
his  signal. 

The  instrument  illustrated  is  designed  for  two-position  signals, 
but  can  be  modified  to  operate  three-position  signals. 


COLEMAN     "LOCK     AND     BLOCK"     SYSTEM. 

The  Controlled  Manual  or  "Lock  and  Block"  instruments, 
made  by  the  Union  Switch  &  Signal  Co.,  are  an  Improved  form 
of  the  Sykes  instrument  and  accomplish  all  and  more  than  the 
original  Sykes  instruments  which  were  imported  from  Eng- 
land. The  Sykes  system,  as  originally  installed  in  the  United 
States,  used  only  one  home  signal  and  a  distant  signal  at  each 
block  tower  for  each  track.  This  arrangement  is  still  used 
in  many  cases  where  there  are  no  switches  at  or  near  the  block 


Fig.    348.      Location    of    Lock    and    Block    Instrument 
Over  Interlocking   Machine. 


T 

Figs.  349-351.     Coleman  Lock  and   Block  Instrument;    Parts  in    "Free"  Position. 


tower.  In  practice,  however,  it  often  has  been  found  con- 
venient to  use  an  advance  block  signal  in  addition  to  the  home 
signal,  in  order  to  conveniently  permit  trains  to  use  the  switches 
situated  between  the  home  and  the  advance  block  signal,  and 
to  expedite  the  movement  of  trains  from  block  to  block  when 
traffic  is  heavy.  On  the  New  York  Central  advance  block  sig- 
nals have  been  installed  at  nearly  all  block  towers  where 
there  are  switches  and  at  some  few  other  towers  where  there 
are  no  switches.  Where  no  advance  block  signal  is  used,  the 
locking  up  track  circuit  and  the  plunger-release  track  circuit 
are  combined  in  one. 

Fig.  352  shows  the  operation  of  the  Coleman  instruments 
for  double  track,  with  home  and  advance  block  signals,  as  in- 
stalled on  the  New  York  Central.  In  this  installation  the  ad- 
vance or  starting  signal  is  known  as  the  block  signal.  A 
train  occupying  track  between  signals  H  and  B  at  tower  X 
is  to  proceed  to  tower  Y.  The  signalman  at  X  calls  Y  by  bell 
and  asks  for  an  "unlock."  If  the  preceding  train  has  cleared 
the  block  at  Y  and  the  instruments  are  normal,  as  shown  in 
the  diagram.  Y  pulls  out  the  plunger  as  far  as  it  will 
go,  thereby  raising  his  banner  to  show  "locked."  This  closes 


the  contact  shown  below  coil  46.  To  insure  signal  H  at  Y 
being  blocked  and  the  terminal  block  track  circuit  unoccupied, 
a  preliminary  circuit  is  provided  from  battery  wire  101,  through 
binding,  post  1,  coil  46,  coil  47,  binding  post  9,  wire  17,  con- 
tact 1  on  home  lever  roller,  wire  14,  front  contact  on  terminal 
block  relay,  to  common  return  wire  100.  If  the  two  condi- 
tions are  fulfilled,  this  circuit  is  completed,  energizing  magnet 
46  and  holding  up  the  banner  to  show  "locked"  by  the  latch 
of  46.  Y  then  releases  his  plunger,  which  is  returned  to  its 
normal  position  by  a  spring.  When  the  plunger  completes  its 
return  stroke,  the  latch  shown  back  of  the  banner  drops  into 
a  notch  in  the  plunger  bar  (or  slide)  and  locks  it  in  the 
normal  position,  at  the  same  time  breaking  the  contact  between 
46  and  47.  But  before  this  contact  is  broken,  another  contact 
is  made  between  46  and  10,  thereby  preventing  the  banner  from 
falling.  The  plunger  cannot  again  be  pulled  out  until  the 
banner  has  been  returned  to  the  normal  or  "free"  position. 
When  the  plunger  completes  its  return  stroke,  the  circuit  from 
Y  is  as  follows:  From  101  through  1,  46,  10,  block  wire 
22  to  block  wire  23  at  X,  6,  block  indicator  80,  5,  48,  locking 
up  relay  contact  to  100.  A  shunt  circuit  is  also  provided  from 


Figs.  352-353 


BLOCK    SIGNALS. 


29 


48  through  49  and  contact  2  on  block  lever  roller  to  100,  the 
purpose  of  which  is  explained  below.  It  should  be  remembered 
tha.t  the  block  wire  numbered  22  at  Y  and  23  at  X  is  a 
continuous  wire.  Indicator  80  clears  when  energized,  showing 
X  that  Y  has  given  an  unlock ;  contact  on  the  armature  of  80 
is  also  closed.  To  clear  the  block  signal  B  at  X  after  the 
unlock  is  given,  the  circuit  is  from  101  at  X  through  4,  contact 
on  indicator  80  (which  is  now  closed),  7,  87,  floor  push  (which 
must  be  closed),  82,  block  lever  lock  magnet,  to  100.  This 


-7errr7/f7cr/  ff/oc/r  Trcfc/r  C/rces/f: 


to  the  position  "train  In  block"  (catching  on  the  bottom  hook 
of  latch  62).  As  the  banner  drops  from  the  "locked"  position, 
the  contact  below  coil  46  opens,  and  energy  from  wire  101, 
which  was  connected  to  wire  22  through  this  part  of  the 
instrument,  is  now  cut  off. 

As  the  train  approaches  Y,  the  signal  H  at  Y  cannot  be 
cleared  unless  signal  B  is  blocked  and  the  track  sections  be- 
tween signals  H  and  B  are  unoccupied.  This  is  provided  for 
by  the  home  lever  lock  which  cannot  be  released  to  clear 


ch  Circuit 
Home  Loc/r  Trarc/r  C/rces/'-f 


Fig.    352.     Standard   Circuit   Plan   for   One   Tower,    Controlled    Manual    Signals,    with    Non-Continuous    Track 

Circuit.     New    York    Central    &    Hudson    River. 
The  plans  at  Towers  "X"  and  "Y"  Referred  to    in  the  Description  are  Identical. 


energizes  the  block  lever  lock  magnet  and  unlocks  the  lever  so 
that  the  signal  B  can  be  cleared.  As  soon  as  X  clears  signal 
B  to  permit  train  to  proceed  to  Y,  one  shunt  of  the  unlock 
circuit  is  broken  at  2  on  block  lever  roller  between  49  and  100. 
The  original  circuit  for  the  unlock,  however,  is  still  retained 
from  48  through  locking  up  relay  contact  at  signal  B  to  100. 
When  the  train  enters  the  locking  up  track  circuit  beyond 


the  home  signal  PI  except  through  the  circuit  101,  floor  push 
(which  must  be  closed),  13,  home  lever  lock,  34,  contact  1  on 
block  lever  roller,  35,  home  lock  relay  contact,  36,  plunger 
release  relay  contact  to  100.  After  the  home  signal  H  has 
been  cleared  and  the  train  enters  the  plunger-release  track 
circuit,  current  flows  from  101  through  2,  62,  8,  18,  back  con- 
tact on  plunger-release  relay  to  100.  This  energizes  62  and  lifts 


LocA/'rtc?  up 
Home  Lock  Track  Circuit.    /^Trcrck  C/rcu/f 


353- 


Circuits  for  Controlled   Manual   Signals,  with  Continuous  Track  Circuit. 

son  River. 


New  York  Central  &  Hud- 


signal B,  this  second  shunt  circuit  is  also  broken  by  the 
armature  of  the  relay  dropping  and  all  connection  between 
the  two  instruments  at  X  and  Y  over  block  wire  22-23  is 
broken  until  X  again  restores  signal  B  to  stop  or  the  train 
passes  completely  out- of  the  locking  up  track  circuit.  As  soon 
as  the  unlock  circuit  is  broken,  the  indicator  at  X  is  de- 
energized.  The  magnet  46  at  Y  is  also  de-energized  and  its 
latch  armature  swings  away,  allowing  the  banner  to  drop 


the  latch,  allowing  the  banner  to  drop  about  *4  in.  to  rest 
on  the  notch  at  the  top  of  the  latch  of  62.  The  banner,  how- 
ever, still  displays  "train  in  block."  As  the  train  passes  out  of 
the  plunger-release  track  circuit,  the  contact  on  plunger-release 
relay  is  broken,  but  62  is  still  energized  by  current  flowing 
through  a  shunt  circuit  from  101  through  2,  62,  armature  of 
62,  3,  15,  contact  4  on  home  lever  roller  (closed  when  signal 
is  cleared)  to  100.  This  current  holds  up  the  latch  of  62 


BLOCK    SIGNALS. 


Fig.  354 


("train  in  block"  still  displayed)  until  contact  4  is  broken 
by  returning  the  home  signal  H  to  stop  behind  the  train. 
When  the  signalman  has  done  this,  the  latch  of  62  drops 
and  releases  the  banner,  which  then  falls  to  the  "free"  posi- 
tion. The  banner  in  returning  to  the  "free"  position  releases 
the  latch  holding  in  the  plunger  bar,  and  an  unlock  can  then  be 
given  for  forwarding  another  train  from  X  to  Y. 

It  will  be  seen  that  an  unlock  can  be  given  by  Y  to  X 
at  any  time,  provided  signals  B  at  X  and  II  at  Y  are  blocked, 
and  the  track  between  them  is  unoccupied.  An  unlock  once 
given  may  be  held  indefinitely  until  used.  In  practice,  notice 
of  the  approach  of  a  train  is  given  some  time  before  its  arrival. 
X  may  clear  home  signal  II  at  any  time  (the  control  of  its 
block  being  the  same  as  already  explained  for  the  corresponding 
signal  at  Y)  ;  before  a  train  comes  within  sight  of  his  distant 
signal  X  asks  Y  for  an  unlock,  and,  on  receiving  it,  clears 
signal  B.  With  both  the  home  and  block  signals  cleared, 
the  distant  signal  can  then  be  cleared  and  the  approaching 
train  sent  forward  without  slackening  speed.  After  the  train 
has  passed  signal  B  at  X  no  other  train  can  follow  toward 
Y  until  the  instrument  at  Y  has  been  restored  to  its  normal 
position  by  the  passage  of  the  first  train  over  the  plunger- 
release  track  circuit  at  Y,  and  the  home  signal  H  at  Y  restored 
to  the  stop  position. 


It  is  essential  in  any  installation  of  these  "controlled  manual" 
instruments,  that  the  first  home  signal  be  semi-automatic  In 
its  operation,  going  to  the  stop  position  automatically  as  soon 
as  a  train  has  passed.  If  this  arrangement  is  not  made,  the 
signalman  at  the  entrance  of  the  first  block,  having  received 
an  unlock  from  the  next  tower  in  advance,  might  leave  his  sig- 
nals in  the  clear  position ;  the  second  signalman  could  in 
turn  do  likewise  and  so  on.  Thus,  continuous  clear  signals 
could  be  displayed  throughout  the  entire  installation,  for  any 
number  of  successive  trains. 

Where  switches  operated  from  the  tower  are  instal'ed  be- 
tween the  home  signal  II  and  the  block  signal  B,  a  switch 
box  is  usually  arranged  to  shunt  the  home  lock  track  circuit 
relay  when  the  switch  is  open,  and  thus  prevent  the  home 
lever  lock  from  being  energized,  as  already  explained.  This 
is  a  precaution  in  addition  to  the  mechanical  locking  between 
the  switch  lever  and  the  home  signal  lever  in  the  tower,  and 
is  valuable  in  case  the  mechanical  connections  to  the  switch 
should  become  disconnected  while  the  switch  was  open,  thus 
allowing  the  switch  lever  to  be  returned  to  normal,  and  the 
home  signal  cleared,  while  the  switch  remained  open.  For 
arrangement  of  circuits  with  non-interlocked  outlying  switches, 
see  Figs.  359-360. 

The    controlled    manual    system    described   in    connection    with 


/%7//7  Battery 

Fig-  354-     Circuits   for   Controlled   Signals   in    Park  Avenue  Tunnel  of  the   New  York  Central,  New  York  City; 
Continuous  Track  Circuit,  Overlaps,  Torpedo  Machines  and  Alarm  Gongs,  but  no  Advance  Block  Signals. 


In  case  the  signalman  at  Y  attempts  to  give  X  an  unlock 
while  a  train  is  in  the  terminal  track  circuit  section,  or  while 
his  home  signal  is  clear,  the  magnet  46  is  de-enerzided  and  its 
latch  will  not  hold  up  the  banner,  which  drops  to  "train  in 
block"  when  the  plunger  is  released.  The  signalman  may  then 
repeat  the  operation  of  plunging  to  give  X  an  unlock  any 
number  of  times,  but  until  magnet  46  is  energized  and  holds  the 
banner  in  the  "locked"  position  no  current  can  flow  from  Y 
to  X  to  unlock  X. 

The  floor  pushes  are  for  the  purpose  of  economy  in  the  use 
of  battery. 

The  purpose  of  coil  47  is  to  introduce  dead  resistance  in 
series  with  coil  46,  while  on  local  circuit,  corresponding  to  the 
resistance  of  the  block  wire  22-23  and  the  indicator  80  at  the 
next  tower.  Its  use  prevents  excessive  current  from  flowing 
through  coil  46,  which  would  tend  to  produce  residual  magnetism 
in  that  coil,  and  it  also  increases  the  efficiency  of  the  main 
battery  for  use  on  other  circuits. 

The  unlock  shunt,  wire  49,  may  be,  and  sometimes  is,  omitted. 
Its  purpose  is  to  provide  a  means  of  operating  the  instruments 
in  case  of  failure  of  the  locking  up  track  circuit.  It  will  be 
seen  that  if  the  circuit  through  48  and  locking-up  relay  con- 
tact to  100  is  broken  (by  failure  of  the  relay  or  track  circuit 
to  operate  properly)  the  unlock  can  still  be  given  when  neces- 
sary and  is  taken  away  every  time  the  block  signal  B  is 
cleared  to  permit  a  train  to  proceed  toward  the  next  tower. 


Fig.  352  provides  complete  protection  against  every  possibility 
of  collision  between  trains,  except  in  case  of  a  train  breaking 
in  two  between  X  and  Y/,  leaving  one  or  more  cars  in  the 
block.  The  signalman  at  Y,  unless  he  carefully  observes  the 
rear-end  train  markers,  may  give  an  unlock  to  X  after  part  of 
a  train  has  passed  out  of  the  block,  while  the  rear  cars  are 
standing  somewhere  between  the  towers.  In  order  to  give 
protection  against  this  possible  danger  a  continuous  track  cir- 
cuit may  be  employed  between  signal  B  at  X  and  signal  H  at 
Y.  Such  an  arrangement  is  shown  in  Fig.  353.  In  effect,  the 
locking-up  track  circuit  at  X  is  extended  through  the  block 
and  is  relayed  through  the  terminal  block  track  circuit  at 
Y.  An  additional  contact  is  added  to  the  track  relay  of  the 
locking-up  track  circuit  at  signal  B  and  the  circuit  which 
unlocks  the  block  lever  is  carried  through  it  as  follows  :  From 
battery  wire  101  to  binding  post  4,  contact  on  armature  of 
indicator  80,  binding  post  7,  wire  87,  floor  push  (which  must 
be  closed),  wire  82,  block  lever  lock  magnet,  wire  83,  front 
contact  on  locking-up  track  circuit  relay,  to  common  wire  1 00. 
The  block  lever  lock  cannot  be  released  to  clear  signal  B  as 
long  as  the  track  section  between  signal  B  at  X  and  signal  H 
at  Y  is  occupied.  Protection  is  also  afforded  against  broken  rails, 
since  a  break  would  de-energize  the  locking-up  relay  and  open 
the  contact  in  the  unlocking  cirauit,  thereby  preventing  signal 
B  from  being  cleared.  The  only  other  difference  between  the 
other  circuits  shown  in  Fig.  35.°.  and  those  shown  in  Fig 


Figs.  355-356 


BLOCK    SIGNALS. 


352  is  that  the  preliminary  circuit,  recfuired  before  an  unlock 
can  be  given,  is  carried  direct  to  common  wire  100  from 
contact  1  on  home  signal  lever  roller  instead  of  through 
contact  on  terminal  block  relay. 

The  shunt  circuit  for  the  unlock  through  wire  49  and  con- 
tact 2  on  the  block  signal  lever  roller  to  common  wire  100  is 
retained,  but  for  a  different  purpose  from  what  was  explained 
in  connection  with  Fig.  352.  It  is  needed  here  in  case 
a  train  has  to  pass  signal  B  for  switching  purposes.  If  the 


The  object  in  putting  in  a  cut  section  at  the  distant  signal  D 
and  relaying  the  locking-up  track  circuit  through  it  to  signal  H 
is  to  simplify  the  connections  in  case  it  is  desired  to  put  in  an 
outlying  switch  between  signals  D  and  H,  or  to  make  D  a 
semi-automatic  signal. 

In  Fig.  354  the  plunger-release  track  circuit  and  the  locking-up 
track  circuit  are  combined,  as  stated  on  page  28,  and  lengthened 
to  form  an  overlap  section  in  advance  of  the  home  signal.  In 
this  explanation,  the  relay  controlled  by  the  track  circuit 
of  this  overlap  section  will  be  termed  the  overlap  relay,  and 
the  relay  in  the  track  circuit  extending  from  the  home  signal 
back  to  the  next  overlap  section  in  rear  will  be  termed  the 
terminal  block  relay.  For  tower  B  to  give  tower  A  an  unlock, 
the  preliminary  circuit  is  from  battery  to  b.  p.  1,  through  in- 
strument to  b.  p.  9,  wire  121,  back  contact  on  home  lever 
lock  to  common  wire  O.  The  home  signal  must,  therefore, 
be  locked  in  the  stop  position.  The  unlocking  circuit  is  from 
battery  to  b.  p.  1,  through  Instrument  to  b.  p.  10,  wire  C-l-N, 
front  contact  on  relay,  wire  126,  front  contact  on  relay,  wire 
116,  front  contact  on  relay,  wire  C-l-S  to  b.  p.  6  at  A,  through 
block  indicator  80  to  b.  p.  5,  wire  103,  front  contact  on 
relay  to  common  wire  O ;  or  from  wire  103  through  spring 
contact  on  home  lever,  normally  closed,  to  common  wire  O. 
The  first  relay  in  this  circuit  is  energized  by  local  battery 
through  front  contact  on  overlap  relay ;  the  overlap  section 
must  be  unoccupied  and  overlap  relay  energized  in  order  to  make 
contact  on  local  relay.  The  second  relay  in  the  circuit  Is 
energized  by  local  battery  through  front  contact  on  terminal 
block  relay.  The  third  relay  is  similarly  energized  through  front 
contact  on  overlap  relay  at  A,  and  the  last  relay  between 
wire  103  and  common  is  also  energized  through  front 
contact  on  overlap  relay  at  A.  The  overlap  section  at  B  and 
the  entire  track  section  between  home  signals  at  A  and  B 
must  be  unoccupied  in  order  to  give  an  unlock.  When  unlock 
has  been  received  at  A,  the  circuit  is  from  battery  to  b.  p.  4, 
contact  on  indicator  80,  b.  p.  7,  wire  101,  floor  push  (which  must 
be  closed),  wire  102,  home  lever  lock  magnet  to  common  wire  O. 
The  home  signal  at  A  can  be  cleared  as  soon  as  the  home  lever 
lock  magnet  is  energized.  As  soon  as  the  train  enters  the 
overlap  section  beyond  the  home  signal  at  A,  the  overlap 
relay  is  de-energized  and  the  unlock  circuit  is  broken  by  the 
relay  between  wire  103  and  common.  This  locks  the  instru- 


I       i     r 


u  u 


-    355-      Two-Lever    Dwarf    Interlocking 
Machine  with   Electric    Locks,    Con- 
trolled from  a  Block  Station. 


signalman  had  obtained  an  unlock  and  should  allow  a  train  to 
pass  signal  B,  without  wire  49,  he  would  lose  his  unlock  as 
soon  as  the  train  entered  the  locking-up  track  circuit.  But 
by  keeping  signal  B  blocked  and  giving  the  train  permission 
to  pass  it  in  that  position  (for  switching  purposes  only),  he 
saves  his  unlock  to  use  when  they  are  ready  to  depart,  and  thus 
avoids  issuing  a  caution  cr./d  which  would  otherwise  be 
necessary  in  order  to  permit  them  to  proceed. 


Bell  arrd  Key  fo  be 
p/acecf  />?  Box  on 


Fig.   356.     Hand    Switch,    Bolt   Locked   by   Dwarf   Ma- 
chine,  New   York  Central   &   Hudson  River. 

ment  at  B  in  "Train  in  Block''  position.  In  case  the  relay 
between  wire  103  and  common  does  not  act  properly,  contact 
is  broken  on  the  unlock  circuit  by  the  spring  contact  on  home 
lever  at  A,  which  is  opened  when  home  signal  at  A  is  cleared. 
As  soon  as  the  train  has  cleared  the  overlap  section  at  B,. 


BLOCK    SIGNALS. 


357-358 


all  relays  are  again  energized,  the  block  instrument  at  B  returns 
to  normal  and  another  unlock  may  be  given. 

Torpedo  machines  are  installed  at  the  home  signals  and  are 
operated  with  the  home  signal  lever.  In  order  to  warn  the 
operator  at  A  not  to  block  the  home  signal  and  put  torpedoes 
on  the  track  before  the  train  has  passed  entirely  beyond  the 
home  signal  a  contact  is  added  to  the  terminal  block  relay  in 
rear  of  home  signal  at  A,  and  current  flows  from  battery  through 
back  contact  on  this  relay,  wire  104,  and  through  a  torpedo 
Indicator  to  common  wire  O.  This  indicator  is  energized  until 
every  pair  of  wheels  in  the  train  has  passed  into  the  overlap 
section  beyond  the  home  signal  and  torpedo  machine.  The 
operator  does  not  return  the  home  lever  to  stop  until  the 
torpedo  indicator  clears. 

If  for  any  reason  a  train  runs  by  the  home  signal  at  A  in 
the  stop  position  a  loud  gong  begins  to  ring.  As  soon  as  the 
first  pair  of  wheels  enters  the  overlap  section,  while  the  rear 
wheels  are  still  in  the  terminal  block  section  in  rear  of  the 
home  signal,  both  the  terminal  block  relay  and  the  overlap 
relay  are  de-energized.  This  closes  the  circuit  from  battery 
through  spring  bell  key  closed,  through  spring  contact  on 
home  lever  (closed  when  signal  is  in  stop  position),  wire  109, 
stick  relay,  wire  105,  back  contact  on  terminal  block  relay, 
wire  147,  back  contact  on  relay  to  common.  The  stick  relay 


he  reverses  this  roller,  contact  2  is  opened,  breaking  connec- 
tion between  wire  167  and  100,  and  de-energizing  magnet  S, 
which  then  locks  the  controller  in  its  reversed  position.  The 
train  may  now  use  the  switch,  and,  if  necessary,  may  clear 
the  main  track  entirely  to  allow  one  or  more  trains  to  pass. 
In  case  it  is  desired  to  do  this,  the  trainman,  after  closing  the 
switch  and  locking  it  for  the  main  track,  restores  the  switch 
lock  to  its  normal  position,  closing  contact  2  on  its  roller.  This 
again  completes  the  circuit  through  magnet  S  (as  already 
described),  and  the  controller  may  then  be  returned  to  its 
normal  position  by  the  signalman.  He  must  do  this  before  he 
can  clear  signal  H,  because,  as  already  stated,  the  circuit  for 
lever  lock  H  is  carried  through  contact  1  on  the  switch  lock 
controller  and  is  closed  in  its  normal  position  only.  When 
he  reverses  signal  H  to  allow  a  train  on  the  main  track  to 
pass  over  the  switch,  he  breaks  the  connection  between  wire 
90  and  wire  163,  locking  controller  S  normal. 

Having  received  an  unlock  from  the  next  tower  in  advance, 
as  already  described,  he  then  clears  signal  B  and  allows  the 
main  line  train  to  proceed.  After  it  has  passed,  he  must 
restore  signal  B  to  the  stop  position  before  he  can  unlock 
the  outlying  switch,  because  the  circuit  for  magnet  S  Is 
carried  through  a  normal  contact  (3)  on  the  block  lever  roller. 
This  arrangement  prevents  him  from  permitting  the  train, 


Fig-  357-     Electric    Lock    with    Semaphore    Indi- 
cator.    The  Union  Switch  &  Signal  Co. 


Electric    Lock    Shown    in    Fig.   357. 
Removed. 


Cover 


is  energized  and  current  flows  from  gong  battery  through  wire 
107,  gong  wire  106,  front  contact  on  stick  relay  to  battery.  The 
gong  continues  to  ring  until  the  operator  at  A  opens  the  spring 
key  and  allows  the  stick  relay  to.  drop. 

Figs.  355-360  show  the  method  used  in  controlling  main  line 
switches  which  are  situated  too  far  awav  from  towers  to  be 
interlocked.  Such  switches  are  operated  by  hand  and  are 
known  as  outlying  switches.  They  are  electrically  locked  and 
controlled  by  the  signalman  in  an  adjacent  tower.  The  arrange- 
ment shown  in  Fig.  355  would  cover  two  separate  switches,  one 
lever  and  one  lock  for  each.  The  lever  mechanically  bolt-locks 
the  switch  in  its  normal  position  and  is  in  turn  interlocked 
with  the  roller  and  segment  of  the  electric  lock.  A  switch 
lock  controller,  Figs.  357  and  358  Is  placed  in  the  tower 
and  connected,  as  shown  in  the  wiring  diagrams.  Communica- 
tion by  bell  code  and  telephone  is  also  provided. 

Fig.  359  shows  the  arrangement  for  an  outlying  switch  be- 
tween the  home  and  advance  signals  and  may  be  used  with 
either  continuous  or  non-continuous  track  circuits.  The  con- 
troller in  the  tower  is  locked  in  either  normal  or  reverse 
position  when  its  magnet,  S,  is  de-energized.  To  permit  a  train 
standing  between  the  switch  and  signal  B  to  use  the  switch, 
the  signalman  closes  the  floor  push  from  battery  wire  101  to 
wire  89,  completing  the  circuit  through  coil  S,  wire  90,  con- 
tact 3,  on  home  lever  roller,  wire  163,  contact  3,  on  block 
lever  roller,  wire  167,  and  contact  2,  on  switch  lock  roller  to 
common  return  wire  100.  This  circuit,  if  complete,  insures 
that  both  the  home  and  advance  signals  are  in  the  stop  posi- 
tion, and  also  that  the  switch  lock  is  normal.  The  signalman 
then  reverses  his  controller,  opening  contact  1,  which  locks  the 
home  signal  lever  normal,  and  closing  contact  2,  which  com- 
pletes the  circuit  from  101  through  wire  164  and  switch  lock 
magnet  to  100,  unlocking  the  switch  lock,  which  must  be 
reversed  by  the  trainman  before  he  opens  the  switch.  When 


coming  out  of  the  siding,  to  follow  the  other  into  the  block 
without  getting  another  unlock,  which  might  otherwise  be 
done. 

The  controller  may  now  be  operated,  the  switch  unlocked  and 
used  and  the  controller  restored  in  the  Seme  manner  as  before. 

An  outlying  switch  between  block  signal  at  one  tower  and 
distant  signal  at  tower  in  advance  is  locked  and  controlled  by 
the  signalman  in  the  tower  in  rear,  by  means  of  the  switch 
lock  controller  shown  in  Fig.  360.  This  controller  is  locked  in. 
either  normal  or  reverse  position  when  the  magnet  S  is  de- 
energized.  The  preliminary  and  unlock  circuits  are  the  same  as 
already  described,  except  that  wire  49  is  continued  through 
roller  on  block  lever  to  roller  contact  5  on  the  switch  lock 
controller,  and  thence  to  common  return  wire  100;  a  relay,  K, 
is  also  introduced,  controlled  through  wires  87  and  81,  by  in- 
dicator 80.  A  train  having  passed  the  signal  B,  and  wishing 
to  use  the  outlying  switch  on  arrival,  stops  and  stands  on  the 
lock-releasing  track  circuit.  Communication  is  established  by  bell 
key  and  telephone  with  the  tower  in  the  rear,  and  an  unlock 
for  the  switch  is  asked  for.  The  circuit  for  unlocking  the 
switch  controller  at  the  tower  is  as  follows :  From  battery 
wire  101,  through  lock  magnet  S,  wire  89,  floor  push,  wire  90, 
contact  1  on  switch  lock  controller,  wire  85,  contact  4  on  block 
lever  roller,  wire  86,  of  switch  lock  L  (now  closed),  wire  58 
and  roller  contact  to  100.  The  switch  lock  controller  in  the 
tower  is  then  restored  to  its  normal  position,  and  by  opening 
roller  contacts  2  and  3  it  locks  itself  and  the  switch  lock  L  in 
the  normal  position.  Any  number  of  trains  may  now  be  sent 
through  the  block  in  the  usual  manner. 

When  the  train  in  the  siding  wishes  to  again  take  the  main 
track,  it  is  necessary  for  the  tower  in  advance  to  give  an 
unlock  to  the  tower  in  rear,  all  signals  being  in  the  stop 
position.  This  energizes  the  relay  K  through  wire  81,  making 
a  front  contact  for  wire  86  and  permitting  the  switch  lock 


Figs.  359-36o 


BLOCK    SIGNALS. 


33 


controller  to  be  unlocked  through  the  following  circuit :  Battery 
wire  101,  lock  magnet  S,  wire  89,  floor  push,  wire  90,  contact  1, 
wire  85,  contact  4,  wire  86,  front  contact  (now  closed)  on 
relay  K  to  common.  The  switch  lock  controller  is  then  re- 
versed, unlocking  the  switch  lock  roller.  When  the  switch 
lock  roller  is  reversed  to  unlock  the  switch,  in  order  to  allow 


wire  218,  "stick"  relay  N,  wire  73,  contact  on  switch  lock  roller 
to  common.  This  permits  the  banner  in  the  instrument  at 
the  advance  block  station,  which  now  shows  ''train  in  block," 
to  drop  to  the  second  latch  of  that  position.  The  relay  N  will 
remain  energized  if  a  car  is  allowed  to  remain  standing  on 
the  track  anywhere  between  signal  B  and  signal  II  through  a 


ock  Lever- 
To  be  Locked  Mor-mal . 


/rtsfnsrrrerrf  3"-fobe  focH&c/  Normal  arrc/  re 


Fig.    359-     Circuits    for    Controlled    Manual    Block    Signals,  with  Non-Continuous  Track  Circuits  and  Outlying 
Switch    Between    Home    and    Advance    Signals.     New  York  Central   &  Hudson   River. 


the  train  to  take  the  main  line,  a  local  indicator  circuit  is 
made  up  as  follows :  From  2-cell  "SS"  battery  through  back 
contact  on  relay  K,  wire  67,  back  contact  (now  closed)  on 
lock-releasing  circuit  relay,  wire  58,  contact  on  switch  lock 
roller  to  1 00.  This  unlocks  the  switch  lock  controller  in  the 
tower,  which  is  then  reversed,  opening  contacts  1,  4  and  5 
and  closing  contacts  2  and  3  ;  opening  contact  4  locks  signal 
B  in  the  stop  position.  Current  then  flows  from  wire  101, 
through  contact  3  on  switch  lock  controller,  wire  64  to  switch 
lock  magnet  L  to  100.  This  unlocks  the  switch  lock  roller, 


"stick"  connection  with  back  contacts  on  the  relays  controlled 
by  this  section  of  track  (wires  75  and  76).  If  the  train  en- 
tirely clears  the  main  line  in  tc.iing  the  siding,  the  switch 
is  thrown  and  then  locked  in  the  normal  position  by  restoring 
the  switch  lock  roller  to  normal,  the  contact  of  wire  73  is 
again  broken  and  if  the  signal  H'  is  in  the  stop  position  the 
banner  at  the  tower  in  advance  drops  to  the  "free"  position. 
Roller  contact  between  wires  58  and  100  (which  was  broken) 
is  now  closed  and  the  switch  lock  controller  magnet  S  is  ener- 
gized through  circuit  as  follows:  From  101,  through  coil  S, 


BtocfrS/'yna/ 
Potver  Opera  fee? ""  N 


Lock  Re/cas/rra  Trac/r 


Loc    Recas/rra 
s*~  CSs-cisSf  Ztfa/Ss  L 


IM^.    360.      Circuits    for    Controlled    Manual     Block    Signals    with    Continuous    Track    Circuits    and    Outlying 
Switch    Between    Two    Block    Stations.     New   York  Central   &   Hudson   River. 


which  must  be  reversed  to  unlock  the  switch,  being  mechanically 
interlocked  with  same.  As  soon  as  this  roller  is  reversed  the 
connection  of  wire  58  to  100  is  broken  and  lock  magnet  S  is 
again  de-energized,  locking  the  switch  lock  controller  in  the 
reverse  position.  Also,  when  the  switch  lock  roller  is  reversed, 
contact  is  made  from  wire  73  to  100,  and  this  completes  a 
circuit  from  battery  at  the  block  station  in  advance,  through 
b.  p.  2,  magnet  62,  of  the  block  instrument,  b.  p.  8,  wire  18, 


wires  89  and  91,  roller  contact  2  (now  closed)  wires  84,  67 
and  65,  contact  operated  by  armature  wire  79,  switch  boxes, 
relay  M,  wire  78,  contact  on  switch  lock  roller  (now  closed), 
wire  77,  front  contact  on  track  relay  to  wire  100.  If  this  cir 
1'iiit  is  made  up  it  insures  that  the  track  section  between  the 
switch  and  the  home  signal  in  advance  is  clear ;  relay  M  is 
energized  and  current  flows  from  local  battery,  through  wire 
60,  contacts  on  M,  wire  59,  indicator  magnet  J,  wire  61  to 


34 


BLOCK    SIGNALS. 


Figs.  361-364 


battery.  This  indicator  when  energized  shows  "clear"  and  per- 
mits the  train  to  leave  the  siding.  After  the  train  is  again  on 
the  main  line  the  switch  is  returned  to  normal  and  locked  by 
the  switch  lock  roller  being  restored  to  normal  position,  and  con- 
troller S  is  unlocked  and  restored  as  already  described.  It  is 
also  necessary  that  the  block  instrument  at  the  tower  in  ad- 
vance be  allowed  to  drop  to  the  position  "train  in  block." 
This  is  done  by  a  combination  of  two  circuits  which  drops  the 
banner  from  "locked"  past  the  first  notch  of  the  "train  in 
block"  position  to  the  second  notch,  as  follows :  Reversing  the 
switch  lock  controller  at  the  tower  in  the  rear  cuts  the  cir- 
cuit of  'Wire  49.  As  soon  as  the  train  passes  the  fouling 
point  in  going  out  of  the  switch  it  de-energizes  the  locking-up 
relay  at  B,  thus  cutting  wire  48.  But  before  this  occurs, 
contact  is  made  in  reversed  position  of  the  switch  lock  roller 
for  wire  73,  thus  causing  current  to  flow  from  battery  at  tower 
in  advance,  through  block  instrument  wire  218,  stick  ifelay  N, 
wire  73  to  common.  As  soon  as  the  train  enters  the  fouling 
section  the  banner  drops  from  the  "locked"  position  to  the 
"train  in  block"  position,  but  the  circuit  made  up  through 
218  has  energized  magnet  62  and  permits  it  to  pass  the  first 
notch,  catching  it  on  the  second.  As  soon  as  the  train  passes 
the  home  signal  H'  at  the  tower  in  advance,  the  plunger  release 
track  circuit  and  the  home  signal  lever  at  that  point  restore 
the  instrument  to  its  normal  position  in  the  usual  manner. 


G.    R.    S.    CONTROLLED    MANUAL    SYSTEM. 

In  Fig.  368  A,  B  and  C  represent  block  stations  on  a  single- 
track  road,  with  train  movement  to  be  made  from  A  in  the 
direction  of  C.  In  order  to  display  "proceed"  signal  at  A,  it 
is  first  necessary  for  operator  at  A  to  request  release  or  unlock 
from  operator  at  B.  If  the  block  is  unoccupied,  the  opposing 
signal  at  B  in  the  stop  position  and  other  conditions  favorable, 
operator  at  B  closes  circuit  controller  on  his  instrument  by 
means  of  lever  12  connected  thereto.  This  action  must  be 
simultaneous  with  the  action  of  the  operator  at  A,  who  closes 
similar  controller  on  instrument  at  that  point  through  lever 
13.  This  joint  action  closes  the  unlocking  circuit  and  current 


Fig.   361.      Section    Through    Block    Instrument. 
General  Railway  Signal  Company. 


Figs.   362-363.     Pipe    Lead-out   Connection   from   Block 

Instrument  to  Signal.     General  Railway 

Signal  Company. 


Fig.  364.     Double   Block  Instrument  for  Single  Track. 


flows  from  battery  at  B  through  wire  1  (Fig.  369),  back  con- 
tacts on  electric  locks  2-2,  contact  3,  wire  5,  safety  contact 
6,  wire  8,  indicator  1  at  A,  wire  9,  contacts  10,  wire  11, 
coils  of  electric  lock  L  at  A,  to  ground  or  common.  Indicator 
colls  at  A  and  B  and  lock  coil  at  A  are  then  energized,  indi- 
cators showing  unlocking  circuit  closed.  Lock  coll  at  A  now 


attracts  armature,  releasing  lock  14  and  permitting  the  with- 
drawal by  the  signalman  of  plunger  15,  which  being  connected 
to  lock  lever  17,  releases  cam  crank  21  and  permits  the  clearing 
of  signal.  The  mechanical  operation  is  effected  by  operator 
turning  crank  16  a  half  revolution.  This  crank  is  directly  con 
nected  to  the  shaft  on  which  ratchet  wheel  18  is  mounted. 


Figs.  365-367 


BLOCK    SIGNALS. 


35 


U 


CD 


TL 


rfk 


t=4 


-WiNf-  -(!. 


IS 


U 


vo  U 


u 


bib 


T 


^ 


w 


u 


U 


BLOCK    SIGNALS. 


Figs.  368-370 


the  latter  having  a  stud,  19,  engaging  slot  20  in  cam  crank 
21.  Thus  the  rotary  movement  of  the  mechanism  is  converted 
into  linear  movement  at  the  pipe  connection  to  clear  the 
signal.  The  machine  is  connected  as  in  Figs.  362-363. 

After    train    has    entered    the   block,    the   signalman   completes 
the  revolution  of  crank  1C,   thus  placing  signal  in  stop  position 


Continuous  track  circuit  without  distant  signals  is  shown 
in  Fig.  367.  In  Fig.  370  a  complete  development  of  the  sys- 
tem is  illustrated  ;  the  arrangement  showing  block,  home,  dis- 
tant and  train  order  signals,  continuous  track  circuit,  indi- 
cators and  electric  locks  at  switches  all  under  the  control  of 
operator  at  adjacent  block  station.  No  movement  may  be  made 


TXl 


Figs.  368-369.     Diagram  of  Circuits  and  Instruments  for  Typical    Installation    of    Controlled    Manual  System  for 

Single  Track.     General   Railway  Signal 
Company. 


and  completing  the  movement.  To  prevent  crank  16  from  being 
turned  except  in  the  proper  direction,  ratchet  wheel  18  is 
engaged  by  a  pawl,  thus  insuring  proper  operation  of  the  crank. 
On  this  ratchet  wheel  a  stud  or  boss,  22,  is  fixed  in  such  a 
manner  that  when  the  crank,  16,  is  restored  almost  to  normal 
position  it  engages  arm  23  of  lock  lever  17,  forcing  same  home 
and  preventing  further  operation  until  another  release  or 
unlock  is  received. 


from  sidings  to  foul  the  main  track  without  the  permission  and 
co-operation  of  the  block  operator  at  the  adjacent  station  and 
the  operator  at  the  far  end  of  the  block,  the  same  co-operation 
being  required  as  for  a  main  track  movement. 


CONTROLLED     MANUAL    ON     PENNSYLVANIA. 

Figs.    371-373    show    the    circuits    used    for    a    Single    Track 
Controlled  Manual  Block   System  on   the  Pennsylvania  Railroad 


Fig.    370.     Arrangement    of    Circuits    for    Complete    Development    of    System,    Showing    Power-operated    Home 
and   Distant   Block   Signals,   Train-order   Signals,   Indicator  and  Electric  Locks  at  Switches,  and 
Continuous   Track    Circuits.     General    Railway   Signal    Company. 


Fig.  365  shows  the  system  as  illustrated  in  Fig.  369  with 
the  addition  of  semi-automatic  or  slotted  signals.  The  signals 
remain  clear  until  the  entire  train  has  passed  them,  the  signals 
returning  to  stop  automatically  immediately  after  the  rear 
end  has  cleared.  Power  operated  distant  signals  may  be  pro- 
vided and  operated  in  conjunction  with  the  block  instrument, 
MS  shown  in  Fig.  366.  These  signais  indicate  caution  at  all 
times,  except  when  the  block  signal  is  clear,  switches  set  for 
the  main  track  and  section  between  the  distant  and  block 
signals  is  unoccupied. 


between  Cameron,  Pa.,  and  Sterling  Run.  This  system  provides 
protection  against  butting  collisions,  but  is  permissive  for 
following  movements.  Electric  approach  locking  is  provided 
at  both  plants. 

At  each  station  there  is  a  block  instrument  for  each  block 
(1-G,  2-G)  ;  there  is  also  a  signal-controlling  instrument  (1-F, 
2-F).  These  instruments  are  similar  to  those  shown  in  Figs. 
357-358.  There  is  also  at  each  station  in  addition  to  the 
ordinary  indicators  an  indicator  (1-C,  2-C)  which  show?  whether 
or  not  the  track  is  occupied  for  a  distance  of  1,000  ft.  beyond 


Figs.  37I~373 


BLOCK    SIGNALS. 


37 


the  advance  signal  ;  and  an  indicator  (1-D,  2-D)  which  shows 
whether  or  not  the  track  is  occupied  between  the  advance 
signal  and  a  point  several  hundred  feet  beyond  the  outlying 
switch.  Switch  indicators  are  placed  at  such  switches  in  addi- 
tion to  the  switch  locks  to  indicate  to  a  train  on  the  siding 
whether  or  not  it  has  permission  to  proceed  on  to  the  main 
line. 

To  move  a  train  from  Cameron  (tig.  371)  to  Sterling  Run 
(Fig.  373)  the  procedure  is  as  follows:  Operator 
at  Cameron  asks  operator  at  Sterling  Run  for  ar-  un- 
lock. This  is  given  by  moving  the  handle  of  controller  1-G 


Track  Section  West  of  Cameron. 


Wiring  in  Cabin  at  Cameron. 


Track    Section    Between    Cameron    and    Sterling    Run. 


on  controller  1G,  middle  circuit  breaker  of  same  controller, 
wire  1G4,  contact  of  relay  SI,  wire  1G5,  contact  on  switch  lock. 
1SK,  wire  1G6,  contacts  on  relays  Tl,  T2,  wire  2G7,  contact 
of  relay  S2  at  Cameron,  contact  of  switch  lock  2SK,  wire  2G5, 
back  contact  of  electro-magnetic  circuit  controller  at 
Cameron,  wire  2G4,  circuit  controller  on  2G,  coils  of 
2G  to  common.  This  energizes  2G  and  releases  its  handle 
for  a  movement  to  the  right.  The  operator  at  Cameron 
moves  handle  of  2G  to  the  right.  This  releases  handle  2F 
through  the  tappet  locking  at  R  and  closes  a  circuit  from  B 
at  indicator  2D,  through  a  point  of  2D,  wire  2F-2G-5H1,  wire 
2F-2G2,  contact  on  lock  5,  circuit  controller  on  lock  5,  wire 
2F-2G3,  circuit  breaker  on  2G,  wire  2F4,  circuit  controller  on 
2F,  coils  2F  to  common.  This  energizes  2F  and  releases  its 
handle.  The  operator  moves  the  handle  of  2F  to  the  right. 
This  releases  the  lever  of  signal  5  and  the  signal  can  be  cleared. 
The  signal  is  put  to  the  stop  position  behind  the  train  by 
the  slot.  The  slot  circuit  is  controlled  by  indicators  2C  and 
2D  when  2G  is  energized.  When  2G  is  de-energized,  as  when 
a  train  is  anywhere  between  stations,  it  is  controlled  by  2C 


Wiring  in  Cabin  at  Sterling  Run.  Track    Section    East    of    Sterling    Run. 

Figs.    371-373.     Circuits    for    Single    Track    Controlled    Manual    Block   Signals.     Pennsylvania    Railroad. 

(see     Fig.     373)      at .  Sterling    Run    to    the    left.     This    closes  only.      The    arrangement    of    contacts    on    lever    5,    where    slot 

a   circuit  from  B,  front  contact  on  relay   1DZ  at   Sterling   Run  5  gets  current  from   B,   is  such  that  the  slot  can  be  kept  ener- 

through    wires    1F-1G-13H1.     1F-1G2,    contact    on    electric    lock  gized    with    a    train    beyond    the    control    of    indicator    2C    if 

13,     controller     on    same     lock,     wire     1F-1G3,     upper    contact  the   lever    is    not   pulled   beyond    the    middle   position    (see   wire 


BLOCK    SIGNALS. 


Fig-  374 


5H5    and   two   lower    contacts   on    lever    5).     This    indication    is 
given   for   permissive   signaling. 

Provision  is  also  made  for  letting  a  train  out  of  a  siding 
at  a  switch  in  the  block  after  any  and  all  trains  admitted 
to  the  block  have  passed  the  switch.  It  is  not  necessary  to 
wait  for  the  block  to  be  actually  cleared  by  a  train  moving 
in  the  facing  direction.  A  train  can  be  let  out  of  a  siding 
after  the  passage  of  a  train  in  the  trailing  direction,  but  not 
while  such  train  is  moving  from  the  block  station  to  the 
siding  switch  (see  switch  lock  circuits  SK). 


THE  ELECTRIC  TRAIN  STAFF  SYSTEM. 

Figs.  374-380  show  the  electric  train  staff  instrument  made 
by  the  Union  Switch  &  Signal  Co.  for  use  on  single  track  lines. 
One  instrument  is  installed  at  each  end  of  the  block  ;  that  is, 
in  a  continuous  installation,  two  at  each  block  station.  Fig. 
381  shows  the  wiring  diagram  for  two:  staff  block  stations.  To 
move  a  train  from  X  to  Y  the  manipulation  of  the  instruments 


the  circuit  19,  20,  21,  8,  7,  6,  5,  4,  22,  23,  24,  25,  17,  16,  15, 
14,  13,  26),  and  then  holds  It  closed,  thereby  deflecting  the 
"current  indicating  needle,"  43,  Fig.  379,  at  X  to  the  right. 
This  informs  X  that  Y  has  furnished  X  current  and  he  pro- 
ceeds to  remove  the  staff  by  turning  the  preliminary  handle, 
45,  Fig.  379,  to  the  right  as  far  as  it  will  go,  which  raises 
the  armature  up  to  the  magnet  K,  transferring  the  current  from 
bell  L  to  the  coil  K88,  through  the  circuit  19,  20,  21,  8,  7, 
6,  5,  4,  22,  23,  27,  28,  25,  17,  16,  15,  14,  13,  26,  and  at  the 
same  time  closing  the  circuit  on  coil  K360  through  the  circuit, 
1,  2,  29,  30,  28,  25,  after  which  the  preliminary  spindle  handle 
is  permitted  automatically  to  return  to  its  normal  position. 
This  unlocks  the  revolving  drum,  8,  Fig.  377,  and  indicates  the 
fact  by  displaying  a  white  instead  of  a  red  disk  in  the  indi- 
cator, 44,  Fig.  379.  The  operator  now  moves  the  end  staff 
up  the  vertical  slot  into  engagement  with  the  drum  (the 
outer  guard  having  first  been  turned  to  the  right  position) 
revolving  the  latter  through  half  a  turn,  using  the  staff  as 


Fig.  374.     Electric  Train   Staff  Instrument.     The  Union  Switch  &  Signal  Co. 


is  as  follows :  The  operator  at  X  presses  bell  key,  A,  the 
number  of  times  prescribed  in  the  bell  code,  which  rings  the 
bell  at  Y,  through  the  circuit  1,  2,  3,  4,  5,  6,  7,  8,  9,  10,  11,  12, 
13,  14,  15,  16,  17.  The  operator  at  Y  first  acknowledges  re- 
ceipt on  his  bell  key  by  ringing  the  bell,  L,  at  X  (through 


a  handle,  and  finally  withdraws  the  staff  through  the  opening 
at  48,  Fig.  379.  In  making  the  half  turn,  the  drum  has 
reversed  the  polarity  of  the  operating  current,  thereby  throw- 
ing the  instruments  at  X  and  Y  out  of  synchronism  with  each 
other  and  moving  the  "staff  indicating  needle,"  42,  Fig.  379, 


Figs.  375-38o 


BLOCK    SIGNALS. 


39 


from  "staff  In"  to  "staff  out."  Immediately  on  withdrawing  the 
staff,  the  operator  at  X  once  more  presses  his  bell  key,  A, 
which  indicates  to  the  operator  at  Y,  by  moving  his  needle  from 
"staff  in"  to  "staff  out"  that  the  operation  is  completed. 

The  staff  is  now  delivered  to  the  train.  The  magnet  K  has 
two  separate  coils,  one  energized  by  the  local  and  one  by  the 
line  battery.  The  construction  of  this  magnet  is  such  that 
when  the  currents  in  both  coils  flow  in  the  same  direction  the 
lines  of  force  pass  around  the  cores  and  connecting  straps,  thus 
forming  no  point  of  attraction  for  the  armature.  When  the 
current  is  reversed  in  one  coil  the  lines  oppose  each  other  and 
the  armature  being  brought  to  the  point  of  attraction,  is 
held  there.  The  polarity  of  the  local  current  going  through 
the  magnet,  K360,  Fig.  381  is  never  changed.  The  polarity 
of  the  current  flowing  through  K88,  Fig.  381,  is  changed 
every  time  the  staff  is  put  in  or  taken  out  of  either  instru- 
ment. This  puts  the  instruments  either  in  or  out  of  syn- 
chronism. With  the  staff  out,  the  circuits  are  as  follows : 
From  the  positive  side  of  the  battery  at  Y,  through  19,  20, 
21,  bell  key,  A,  closed,  8,  7,  6,  5,  17,  25,  24,  23,  22,  4, 
16,  15,  14,  13,  26,  to  the  negative  side  of  the  battery  at  Y. 
If  an  attempt  should  be  made  to  release  a  staff  by  turning 
the  preliminary  handle,  the  operating  current  would  be  trans- 
ferred from  the  bell,  L,  to  coil  K88,  through  19,  20,  21,,  bell 
key,  A,  closed,  8,  7,  6,  5,  17,  25,  28,  27,  23,  22,  4,  16,  15,  14, 
13,  26,  to  the  negative  side  of  the  battery  at  Y.  By  comparing 
this  circuit  with  the  one  described  for  releasing  the  staff  it 
will  be  seen  that  in  the  former  the  currents  flowing  through 
coils  K360  and  K88  oppose  each  other,  and  in  the  latter  they 
do  not,  which  prevents  the  releasing  of  a  staff. 

On  arrival  of  the  train  at  Y  the  staff  is  delivered  to  the 
operator,  who  places  it  in  the  opening,  48,  Fig.  379,  of  his  in- 
strument, having  first  turned  the  outer  guard,  37,  Fig.  379, 
to  place,  moves  the  staff  into  engagement  with  the  drum,  9, 
Fig.  377,  revolves  it  through  one-half  turn,  using  the  staff  as  a 
handle,  and  allows  it  to  roll  down  the  spiral.  He  then  presses 
his  bell  key  the  prescribed  number  of  times,  thus  notifying 
X  that  the  train  is  out  of  the  section,  which  operation  also 


1-2H 


) 


10" 


Figs.    375-376.      Electric   Train    Staff   with    Permissive 
and    Pusher   Attachments. 


Figs.    377-379.     Electric    Train     Staff    Instrument. 
Names    of   Parts    of    Electric    Train    Staff    Instrument;    Figs.    377-379. 


i 

2 

4 
6 

7 
8 

9 
10 

12 
15 

18 

22 

23 
24 


Back  and  Cover 
Indicator 

Locking  Bar  for  Disk  Indicator- 
Drum  Locking  Lever 
Armature  Raising  Lever 
Locking  Drum  Gear 
Receiving  Drum  Gear 
Operating  Lever  Cam 
Eccentric 
Terminal  Post 
Contact  Spring 
Connecting  Bar 
Magnet 
Terminal  Post 


26  Single  Stroke  Bell 

29  Contact  Spring  of  Bell  Key 

37  Shield  Plate  and  Knob 

38  Glcss  for  Indicator   Opening 

39  Slot  in  6 

40  Locking  Drum 

41  Vertical  Slot 

42  Staff  Indicator  Needle 

43  Current  Indicator  Needle 

44  Indicating  Disk 

45  Preliminary  Handle 

46  Push  Button 

47  Spiral  Slot  _ 

48  Opening  for   Withdrawing  Staff 


Fig.  380.  Electric  Train 
Staff  Instrument, 
Mounted,  Showing 
Arrangement  of 
Lightning  Arresters. 


4o 


BLOCK    SIGNALS. 


Figs.  381-382 


moves  the  "staff  indicating  needle"  at  X  from  "staff  out"  to 
"staff  in."  The  operator  at  X  presses  his  bell  key  in  acknowl- 
edgment, and  by  so  doing  moves  the  "staff  indicating  needle" 
at  Y  from  "staff  out"  to  "staff  in."  The  machines  are  now 
synchronized  and  another  staff  can  be  obtained  from  either 
In  the  manner  outlined  above.  The  staff  being  put  in  the 

X  s^Po/ar/zecf  /rrcf/cafor 
22 


the  current  flowing  through  the   magnets  K360,   K88,  are  again 
opposing  each   other,   consequently   a   staff   can    be   released. 

Cases  occur  where  it  is  desirable  to  allow  one  or  more  trains 
to  follow  one  another  into  the  block  at  short  intervals  before 
the  first  train  has  passed  out.  This  is  known  as  the  per- 
missive system  and  consists  of  an  attachment  (Figs.  375-376  and 


VWWWWV 
ADJUSTABLE 
RESISTANCE 


Fig.  381.     Circuit  for  Electric  Train  Staff. 


CIRCUIT  CONTROLLER 
IN  PUSHER  ATTACHMENT 


Fig.    382.     Circuits    for    Pusher 


Attachment,    Showing  Connections  when  Pusher  Staff  is  Out. 
Electric   Train    Staff  System. 


instrument  at  Y,  the  circuits  are  as  follows  :  From  the  positive 
side  of  the  battery  at  Y,  through  19,  20,  21,  bell  key,  A, 
closed  at  Y,  through  8,  14,  15,  16,  4,  22,  23,  24,  25,  17,  5,  6, 
7,  13,  26,  to  the  negative  side  of  the  battery  at  Y.  Should 
a  release  be  required,  the  preliminary  spindle  at  X  would  be 
turned  and  the  current  transferred  from  the  bell  to  magnet 
K88  through  the  following  circuit:  from  the  positive  side  of 
the  battery  at  Y  through  19,  20,  21,  bell  key  closed  at  Y, 
through  8,  14,  15,  16,  4,  22,  23,  27,  28,  25,  17,  5,  6,  7,  13,  26, 
to  the  negative  side  of  the  battery  at,  Y.  It  will  be  seen  that 


390-392)  to  the  absolute  machine  at  each  end  of  the  section 
with  one  permissive  staff.  An  absolute  staff  is  always  locked 
in  a  perniis.-ive  attachment  when  it  does  not  contain  the  per- 
missive staff. 

Now,  assuming  that  the  permissive  staff  (A,  Fig.  402)  is  ;it 
X,  to  operate  this  feature,  an  absolute  staff  is  withdrawn  from 
the  instrument  at  X  in  the  usual  manner  and  used  as  a  key 
to  unlock  the  attachment  containing  the  permissive  staff,  which 
is  then  taken  out.  The  opening  of  the  base  and  the  removal 
of  the  permissive  staff  locks  the  absolute  staff  in  the  permissive 


Figs.  383-388 


BLOCK    SIGNALS. 


\ /7 7 
21     10     19      17 


Figs.  3^3-385-     Pusher  Attachment   for   Electric   Train    Staff   System. 


Names   of   Parts   of  Pusher  Attachment   for   Electric  Train   Staff.    Figs.   383-385. 


i 
2 
3 
4 
5 
6 

7 
8 

9 
10 
ii 

12 


Cover 

Bracket  for  Contact  Springs 

Contact  Spring 

Terminal  Post 

Contact  Lever  Bracket 

Pivot  Pin  for  7 

Contact  Lever 

Contact  Spring  for  Lever  7 

Pin  Connecting  7  -with  11 

Hook  for  Spring  12 

Eccentric  Rod 

Releasing  Spring  for  7 


13  Bearing  for  Locking  Dog  14 

14  Locking  Dog 

15  Right-hand   Half   of  Socket   for 

Pusher  Staff 

16  Left-hand   Half    of    Socket    for 

Pusher  Staff 

17  Pivot  for  Locking  Levers 

18  Separator 

ig    Long  Locking  Lever 

20  Short  Locking  Lever 

21  Stud  for  Holding  Cover  in  Place 


Names  of  Parts  of  Intermediate  Siding  Staff  Instrument;  Figs.  386-388. 


B  Locking  Drum  and  Frame 

1  Back  and  Cover 

2  Indicator 

3  Indicator  Disk 

4  Connecting   Bar    for   Disk    Indi- 

cator 

5  Drum   Locking  Lever 

6  Drum     Locking     and     Armature 

Raising  Lever 

7  Operating  Lever  Cam 

8  Eccentric 

g  Eccentric  Rod 

10  Bracket   for   Supporting    n    and 


11  Armature  Lever  24 

12  Lever    for    Pole    Changer    Con-        25 

tact  Springs  26 

13  Bracket  for  Contact  Springs  27 

14  Contact  Spring  for  ii  28 

15  Contact  Spring  for  12  29 

16  Contact  Spring  for  13 

17  Terminal  Post  30 

18  Sleeve   and   Machine   Screzv   for 

Bracket  13  31 

19  Magnet  32 

20  Terminal  Post  33 

21  Bracket    for   Bell    Terminals  34 
22-23  Single  Stroke  Bells 


Bell  Magnet 
Terminal  Board- 
Insulating  Bushing 
Push   Button   Circuit    Controller 
Contact  Spring 
Short     Contact     Terminal    Post 

for  27 
Long     Contact     Terminal     Post 

for  27 
Front  Plate 

Glass  for  Indicator  Opening 
Hasp 
Base 


BACK  VIEW  WITH  COVER  REMOVED 


SIDE  VIEW  SHOWING  COVER  IN  SECTION 


FRONT    VIEW 


Figs.    386-388.      Intermediate    Siding    Staff    Instrument;  Electric   Train    Staff   System. 


BLOCK    SIGNALS. 


Fig.  389 


attachment,  there  to  remain  until  the  permissive  staff  is  re- 
placed. The  permissive  staff  consists  of  a  steel  rod  and  eleven 
removable  rings,  any  one  of  which  authorizes  a  train  to  pass 
through  the  section  to  Y.  If  less  than  12  trains  are  to 
follow  each  other,  the  last  one  takes  all  the  remaining  rings 
and  the  steel  rod.  When  all  the  rings  and  the  rod  are  re- 
ceived at  Y,  the  operator  reassembles  them  into  the  complete 
permissive  staff  which  he  then  places  in  the  base  of  his  per- 
missive attachment  and  locks  it  there,  releasing  the  absolute 
staff  already  in  the  lock  of  this  instrument.  He  then  re- 
moves the  absolute  staff,  which  he  restores  to  the  absolute 
instrument  in  the  regular  manner.  The  machines  are  now 
synchronized  and  a  movement  can  be  made  with  an  absolute 
staff  in  either  direction,  and  from  Y  to  X  with  the  permissive. 
If  it  Is  again  found  necessary  to  move  several  trains  from  X 
to  Y  under  the  permissive  system,  the  permissive  staff  must 
be  taken  out  by  Y,  as  before  described,  and  forwarded  to  X 
as  a  whole  by  the  first  train  moving  in  that  direction.  When 
the  train  receives  the  entire  permissive  staff  it  confers  the 
same  rights  as  does  an  absolute  staff. 

Where  signals  are  used  to  indicate  to  an  approaching  train 
whether  or  not  it  will  receive  a  staff  (Fig.  404),  an  instrument 
known  as  the  staff  lever  lock  (Figs.  396-398)  is  attached  to  each 
lever  operating  such  signals.  To  clear  a  signal,  the  staff  after 


the   staff   circuits    will    remain    broken   until    the   handle   of   the 
circuit   controller    is   again    locked   in    its   normal   position. 

If  in  some  sections  there  is  a  siding  of  sufficient  length  to 
hold  a  train,  but  traffic  does  not  warrant  placing  a  staff  block 
station  at  that  point,  a  special  instrument  (Figs.  386-389) 
is  placed  at  the  siding,  which  enables  it  to  be  used  for  a 
meeting  or  passing  point.  The  operation  is  as  follows :  A 
train  arriving  at  the  staff  station  X  has  not  time  to  proceed 
to  Y,  but  can  proceed  as  far  as  the  siding.  The  operator  at  X 
gives  the  train  the  staff  with  instructions  to  proceed  to  the 
siding.  Unlocking  the  switch  with  the  staff,  the  train  takes  the 
siding,  closes  and  locks  the  switch,  places  the  staff  in  the 
siding  instrument  and  turns  the  drum  to  the  right.  The  staff 
is  now  locked  in  the  instrument  and  the  staff  instruments  at 
X  and  Y  are  synchronized  and  the  fact  indicated  to  both 
operators,  so  that  trains  may  be  sent  through  the  section  In 
either  direction.  When  all  trains  having  precedence  over  the 
one  in  the  siding  have  passed  through  the  section  and  the 
staffs  have  been  replaced  in  the  instruments,  X  and  Y  acting 
in  conjunction,  can  release  the  staff  at  the  siding,  which  on 
being  removed  changes  the  circuits,  so  that  no  staff  can  be 
released  at  either  X  or  Y.  The  train  on  the  siding  then  closes 
the  switch  with  the  staff  and  proceeds  to  Y  or  back  to  X. 
A  junction  or  diverging  line  may  be  situated  between  two 


Fig.    389.      Circuits    for    Intermediate    Siding   Staff    Instrument;    Electric    Train    Staff    System. 


being  withdrawn  is  first  used  to  unlock  the  lever  lock.  The 
signal  is  then  cleared  and  the  staff  removed  from  the  lock  and 
delivered  to  the  train.  To  insure  the  signals  being  restored 
to  stop  position  behind  the  train,  the  act  of  unlocking  the 
signal  lever  opens  the  staff  circuit  and  no  communication  can 
be  made  between  the  two  staff  stations  until  the  signal  is  at 
stop  and  the  lever  locked  in  that  position.  This  does  not  in- 
dicate, however,  that  the  operator  will  have  the  staff  ready  for 
delivery  by  hand,  or  in  the  mechanical  deliverer.  To  cover 
this  point,  an  electric  slot  is  attached  to  the  signal  governing 
train  movements  into  the  staff  section.  This  slot  is  controlled 
by  the  staff  lever  lock  and  the  mechanical  deliverer  (Figs. 
403-405),  so  that  before  the  signal  can  be  cleared  the  staff 
must  be  released,  used  to  unlock  the  signal  lever  and  put  in 
the  staff  deliverer,  which  closes  the  circuit  on  the  electric  slot. 
The  signal  can  then  be  cleared.  With  this  arrangement,  there- 
fore, a  clear  signal  cannot  be  given  until  the  staff  is  actually 
in  the  deliverer.  When  the  train  picks  up  the  staff,  the  circuit 
in  the  slot  is  opened  automatically,  putting  the  signal  to  dan- 
ger. The  signal  cannot  again  be  cleared  until  the  operation 
described  above  is  repeated.  Figs.  393-395  show  three  views  of 
a  circuit  controller  attachment  which  is  used  in  connection  with 
electric  or  electro-pneumatic  signals,  instead  of  the  mechanical 
lock  (Figs.  396-399)  just  described.  It  is  arranged  to  control 
the  staff  and  signal  circuits.  The  circuits  controlling  the  signal 
for  a  movement  into  the  staff  section  cannot  be  closed  until  the 
staff  has  been  used  to  release  the  handle  of  the  controller. 
The  staff  can  then  be  taken  out  and  given  to  the  train,  but 


points  most  suitable  for  staff  stations.  Such  points  can  be 
controlled  the  same  as  a  passing  siding. 

The  staff  is  also  used  as  a  key  to  unlock  siding  switches, 
which  may  occur  between  staff  stations.  The  switch  lock 
(Figs.  400-401)  is  so  designed  that  the  staff  cannot  be  removed 
from  the  lock  until  the  switch  is  set  and  locked  for  the  main 
line,  thus  providing  protection  against  misplaced  switches. 

Another  adjunct  to  the  staff  system  is  known  as  the  pusher 
engine  attachment  and  staff.  It  is  used  on  heavy  grades  where 
pusher  engines  are  required  and  is  intended  to  obviate  the 
necessity  of  the  pusher  engine  preceding  through  the  entire 
staff  section.  It  is  also  evident  that,  in  such  cases,  all  the 
staffs  would  in  time  be  brought  to  the  bottom  of  the  grade. 
It  consists  of  a  separate  device  which  may  be  attached  to  any 
absolute  staff  instrument  (Figs.  375-376  and  382-385),  and  con- 
tains a  staff  of  special  design  (Nos.  5-8,  Fig.  402),  which  can  only 
be  released  by  a  regular  staff,  though,  unlike  the  permissive  staff, 
it  can  be  out  of  its  receptacle  at  the  same  time  as  the  regular 
staff.  When  so  removed  it  opens  the  controlling  circuits  of 
the  system  (Fig.  382),  preventing  any  other  movement  being 
made  until  it  has  been  returned  and  locked  in  the  pusher 
attachment.  The  operation  is  as  follows :  A  train  with  a 
pusher  wishes  to  proceed  trom  Y  to  X.  X  releases  a  staff  at 
Y  and  Y  uses  this  staff  to  release  the  pusher  staff.  Y  then 
hands  the  regular  staff  to  the  train  and  the  pusher  staff  to 
the  pusher  engine.  The  train  passes  through  the  section  and 
delivers  the  regular  staff  at  X.  This  is  placed  in  the  instru- 
ment there ;  the  pusher  engine  retains  the  pusher  staff  and 


Figs.  390-395 


BLOCK    SIGNALS. 


43 


Locking  Drum 

Cover 

Drawer 

Drawer  Lock 

Cradle 

Guard  Bar  for  Permissive 

Hinge  Pin 

Permissive  Staff  Shield 

Bed  Plate 

Cover  Plate 

Cover  Bar 

Eccentric  Lever 


8  6 

Figs.    390-392.     Permissive     Attachment     for     Electric  Train   Staff   System. 


Names  of  Parts  of  Permissive  Attachment;  Figs.  390-392. 


Staff 


12  Lock  Lever 

13  Eccentric  Rod 

14  Lock  Bar  Operated  by  Permis- 

sive Staff 

15  Lock  Bar  Operated  by  Eccentric 

16  Lock  Bar  Operated  by  2 

17  Crank  for  Operating  16 

18  Dog  for  Operating  17 

19  Spring  for  18 

20  Spring  for  14 

21  Socket  for  19  and  20 

22  Stud  for  Cover 


M  1 


21 


22    16 


24 


Figs.  393-395.     Circuit  Controller  Attachment  for   Electric  Train   Staff  System. 


Names  of  Parts  of  Circuit  Controller  Attachment;  Figs. 


Locking  Drum  and  Frame  9 

Cover  10 
Contact  Spring  Bracket 

Contact  Spring  for  2  n 
Contact    Spring    with    Terminal        12 

Post  13 

Terminal  Post  14 

Long   Terminal  Post  for  4  15 

Short  Terminal  Post  for  4  16 

Bracket  for  10  17 


Pivot  Pins  18 

Contact      Lever      Operated  by         19 

E.C centric  20 

Contact  Spring  for  10  21 

Hook  on  10  for  14  22 

Pin  for  10  and  15  23 

Spring   for   Releasing   Lever  10         24 

Eccentric  Rod  25 

Bracket   for    Contact   Levers  18         26 
Separator 


393-395- 

Contact  Lever  Operated  by  Cam 

Contact  Spring  for  18 

Cam  for  Operating  18 

Locking  Dog 

Bearing  for  23 

Shaft 

Bushing  for  Shaft  23 

Arm  for  Shaft  23 

Handle 


44 


BLOCK    SIGNALS. 


Figs.  396-402 


_T 


/                         \     B 

/                       \ 

I 

2 

3 

X~N                       s~^ 

4 

r\  \^)  &~ 

5 

\^—^/ 

6 

^  —  ^ 

7 

8 

9 

10 

ii 

12 

13 

14 

15 

©  © 

Na 

(2^  © 

i 

15 

2 

3 

4 

5 

6 

7 

8 

u 

Names    of    Parts    of    Staff    Lever 
Lock;  Figs.   396-398. 

Locking  Drum  and  Frame 

Cover 

Terminal  Board 

Two-Way    Terminal 

Bracket  for  Contact  Springs 

Contact  Spring  for  4 

Terminal  Post 

Lerer  for  Contact  Springs 

Contact  Spring  for  7 

Pin  with  Cotters 

Eccentric  Rod 

Eccentric  Rod  Spring 

Plunger 

Plunger  Guide 

Stud  for  Holding  Cover  in  Place 

Insulating  Bushing 

Names  of  Parts,  Staff  Switch  Lock; 

Figs.  400-401. 

Case 

Cover 

Hinge  Pin 

Front  Plate  and  Base 

Locking  Dog 

Stud  for  Locking  Dog 

Tap  Bolt,  for  Fastening  Lock  to 

Lever 

Screw,  Fastening  4/01 
Screw,  Fastening  4/01 


Figs.  396-398.     Staff  Lever  Lock  for  Electric  Train  Staff  System. 


Fig.  399.     Staff   Lever    Lock   Applied   to    Saxby    & 
Farmer  Interlocking  Machine. 

Names   of   Parts   of   Standard,   Pusher  and   Permissive 
Staffs;   Fig.  402. 

A  Permissive  Staff  Complete  with  Disks  and  Knob 

1  Absolute  Staff,  \To.  i 

2  Absolute  Staff,  No.  2 

3  Absolute  Staff,  No.  3 

4  Absolute  Staff,  No.  4 

5  Pusher   Staff,    No.    i 

6  Pusher  Staff,   No.    2 

7  Pusher   Staff,    No.    3 

8  Pusher  Staff,   No.   4 


u 

FRONT  VIEW  WITH  COVER  REMOVED  SIDE  VIEW  IN  SECTION 

Figs.   400-401.     Staff   Switch    Lock;    Electric   Train 
Staff  System. 


Fig.    402.       Standard,    Pusher    and    Permissive    Staffs; 
Electric  Train  Staff  System. 


Figs.  403-405 


BLOCK    SIGNALS. 


45 


< r'e'-- 


Fig.  403.     Staff  Catcher,  Union  Pacific;  and  Per- 
missive and  absolute  Staff  Pouches,  Great 
Northern. 


Fig.    405. 


Staff    Catching    Apparatus;    Electric    Train 
Staff  System. 


Fig.    404.     High    Speed    Staff    Catcher,    Electric    Train 

Staff  System.     Cincinnati,    New  Orleans 

&   Texas   Pacific. 


Names   of   Parts   of   Train   Staff   Catching  Apparatus; 

Fig.  405. 

A    Ring  Staff  Pouch 
B     Pouch  for  Permissive  Staff 
C     Pouch  for  Permissive  Staff  Disk 


returns  to  Y.  Until  this  latter  staff  is  put  into  the  pusher 
attachment  at  Y  and  locked,  the  staff  circuits  are  not  re- 
established and  no  other  staff  can  be  released. 

Absolute  staffs  can  be  furnished  in  two  pieces,  screwed 
together  when  so  desired,  the  object  of  this  being  to  deliver 
one-half  to  the  engineman  and  the  other  half  to  the  conductor 
of  the  train,  so  that  should  a  train  break  in  two  and  part  remain 
in  the  section,  the  forward  portion,  on  leaving  the  section, 
would  deliver  only  one-half  of  the  staff,  which  would  not  be 
sufficient  to  unlock  the  machine. 

To  avoid  the  possibility  of  the  staff  belonging  to  one  pair  of 
instruments  in  a  continuous  installation  being  used  to  unlock 
one  of  another  pair  at  either  end  of  the  block,  staffs  are  made 
in  four  different  patterns  (Nos.  1-4,  Fig.  402),  so  that  it 
would  be  necessary  to  carry  one  staff  improperly  through  three 
entire  blocks  before  reaching  one  where  it  would  fit  an 
instrument. 


46 


BLOCK    SIGNALS. 


Figs.  406-411 


AUTOMATIC 


THE  TRACK  CIRCUIT 


The  track  circuit,  which  is  the  vital  feature  of  modern  block 
signaling  and  has  made  the  present  high  development  of  the  art 
possible,  Is  a  simple  electrical  device.  Its  essential  feature  is  a 
section  of  track  insulated  at  each  end  from  the  adjoining 
sections  of  the  track.  Each  rail  in  the  section  is  connected  to 
the  ones  adjoining  by  bond  wires,  for  the  purpose  of  making 
a  continuous  conductor  from  one  end  of  the  section  to  the 
other.  The  contacts  made  by  ordinary  rail  splices  are  not  good 


The  armature  is  attracted  to  the  magnet  when  the  latter  is 
energized  and  is  drawn  away  by  gravity  or  by  a  spring  when 
the  magnet  is  de-energized.  The  armature  carries  one  or  more 
fingers  for  making  or  breaking  electric  circuits  through  points 
or  stops. 

The  presence  of  a  pair  of  wheels  or  train  in  the  section  will 
short-circuit  the  battery,  shunting  the  current  out  from  the 
relay  and  causing  its  armature  to  drop,  because  the  resistance 


Track  Baffery 


\ 
[__  i 

*-~5* 


Fig.  406.     Simple  Track  Circuit. 


,                .                                 WW/s 

-»— 

w 

L 

x-fl^ 

**fl"ifVT- 
UHlk 

Fig.    407.     Track    Circuit    Occupied    by    Train    Moving       Fig.   408.      Track    Circuit    Occupied   by   Train    Moving 
from  Relay  to  Battery.  from  Battery  to  Relay. 


Fig.    409.      Cut    Section    Track    Circuit— a    Single    Block    Section    Divided    in    the    Middle    Because    of    Difficulty    in 

Operating    Long   Track    Circuits. 


Fig.  410.     Cut  Section  Track  Circuit.     Train  in  Relayed  Half. 


Fig.  411.     Cut  Section  Track  Circuit.    Train  in  Relaying  Half. 


electrically,  owing  to  wear,  rust  and  the  loosening  of  bolts. 
Two  bond  wires  are  usually  used  at  each  joint,  so  that  should 
one  break,  the  circuit  will  remain  continuous  through  the 
other.  These  bond  wires  are  secured  to  the  rail  by  means  of 
"channel  pins"  or  other  suitable  devices.  On  electrically  oper- 
ated roads  where  tracks  are  bonded  for  the  return  propulsion 
current  with  heavy  copper  bonds,  no  additional  bond  wires 
are  necessary.  At  one  end  of  the  insulated  track  section  a 
battery  is  placed,  the  positive  terminal  being  connected  to 
one  rail  and  the  negative  terminal  to  the  other.  At  the  other 
end  of  the  section  a  relay  is  connected  to  the  rails  in  a  similar 
manner.  Fig.  406  shows  a  typical  track  circuit.  Current  flows 
from  the  positive  side  of  the  battery  through  the  lower  rail, 
the  relay  and  the  upper  rail  back  to  battery.  This  keeps  the 
relay  energized. 

The  track  relay  is  a  development  of  the  instrument  of  the 
same  name  used  in  the  telegraph.  It  consists  of  an  electro- 
magnet of  the  horse-shoe  type,  provided  with  an  armature. 


through  the  wheels  and  axle  of  an  ordinary  car  or  engine  Is 
infinitesimal  compared  with  that  of  a  relay  of  three  and  a  half 
ohms  or  more.  Consequently  the  relay  is  deprived  by  the 
wheels  and  axles  of  current  necessary  to  maintain  its  attractive 
power  for  the  armature.  The  minimum  resistance  usual  in 
track  relays  is  tnree  and  a  half  ohms.  Fig.  407  shows  the 
effect  of  a  train  on  the  track  circuit;  the  train  is  assumed 
to  be  passing  from  the  relay  end  to  the  battery  end  of  the 
section.  The  effect  would  be  the  same  should  the  train  move 
in  the  opposite  direction  with  respect  to  the  battery  and  relay 
(Fig.  408),  except  that  the  relay  would  not  release  quite  so 
quickly.  This  is  in  part  due  to  the  self-induction  of  the  circuit 
through  the  relay  coils,  the  rails  and  the  axles  of  the  train. 
It  is  due  more,  however,  to  small  leakage  from  the  adjoining 
section  and  the  effects  of  stray  earth  currents  which  are 
always  present  to  a  greater  or,  less  degree.  A  broken  rail 
would  also  open  the  circuit  and  de-energize  the  relay. 

Circuits    for    the    control    of    various    signaling    devices    are 


Figs.  412-421 


BLOCK    SIGNALS. 


47 


3— 

Fig.  412.    Normally  Open  Track  Circuit. 


*HI 


Fig.  413.      Normally  Open  Track   Circuit  Occupied  by 
Train. 


D 


tUML. 

Fig.  414.    "Single  Rail"  Track  Circuit,  Normally  Closed. 


Fig.   415.     "Single   Rail"   Track   Circuit, 
Normally  Open. 


Fig.    416.     Normally    Closed    Track    Circuits,   with    Normally  Open  Track  Circuit  Superimposed. 


Fig.    417.      Simple    Polarized    Track    Circuit; 
Pole   Changer   Normal. 


Fig.    418.      Simple    Polarized    Track    Circuit;     Pole 
Changer    Reversed. 


-r.K' 

rtf 


r.c^ 


X:VV 

n 

.'^H 


Fig.    419.      Cut    Section,    in    Polarized    Track    Circuit;  Pole  Changer  Normal. 


li*J*- 


Fig.  420.     Cut  Section,  in  Polar-zed  Track  Circuit;   Pole  Changer   Reversed. 


-strr« 
nnpr-»| 


< 


Fig.    421.     Polarized    Track    Circuit    with    Cut    Section,   Relaying  Section  Occupied  by  Train. 


48 


BLOCK    SIGNALS. 


Figs.  422-430 


broken  through  the  contact  points  of  the  track  relay.  Such 
apparatus  cannot  be  operated  directly  by  the  track  circuit 
because  to  furnish  It  with  sufficient  current  a  battery  of  large 
electro-motive  force  would  be  needed.  On  account  of  the  low 
insulation  resistance  of  the  ties  and  ballast  it  is  unwise  to 
use  a  battery  of  more  than  about  two  volts  potential.  With 
any  higher  voltage  the  leakage  from  rail  to  rail,  especially  in 
wet  weather,  becomes  equivalent  to  the  presence  of  a  train  in 
the  section.  For  the  same  reason  track  circuits  cannot  be 
made  of  unlimited  length.  The  resistance  of  the  rails  also 
has  to  be  considered  in  determining  the  length  of  a  track  circuit. 
Almost  any  kind  of  closed  circuit  primary  battery  can  be  used 


rails  and  of  the  battery  and  relay  leads  is  disregarded,  also 
that  of  the  ties  and  ballast.  In  calculating  the  table  Ohm's 

E  X  1000 
law  is  used  in  the  form  I  —  —          — ,  where  I  is  the  current, 

(B  +  B) 

in  milli-amperes,  E  is  the  electro-motive  force  in  volts,  B  the 
internal  resistance  of  the  battery  in  ohms,  and  R  the  external 
resistance  of  the  circuit  (relay)  in  ohms.  The  factor  1000  is 
used  in  the  numerator  to  reduce  the  result  to  mill, -amperes. 
Where  cells  are  placed  in  multiple  or  parallel  the  internal  re- 
sistance of  the  battery  is  reduced  in  proportion  to  the  number 
of  cells;  two  cells  reduce  it  to  %,  three  cells  to  %,  etc.  Where 


Fig.  422. 


Fig.  423. 


HI 


Fig.  424. 


Fig.  425. 


Figs.     422-425. 


Possible    Arrangements 
Track    Circuit   Battery. 


of     Cells     of       Figs.    426-429     Common    Arrangements     of    Cells 
Track   Circuit    Battery.     The    Letters   Refer 
to  the   Curves,  Fig.  430. 


of 


to  supply  current  to  a  track  circuit,  but  in  practice  gravity 
or  storage  is  ordinarily  used.  Gravity  battery  is  used  to  a 
greater  extent  than  any  other  type  of  primary  battery  on 
account  of  its  suitability  to  closed  circuit  work.  It  has  a  high 
Internal  resistance  compared  with  its  electro-motive  force,  and 
therefore  will  not  exhaust  as  rapidly  as  other  types.  Potash  or 
soda  batteries  might  be  used  by  inserting  resistance,  in  the 
same  manner  as  with  storage  battery,  except  that  they  are 
found  not  to  be  so  economical  in  practice.  When  gravity  bat- 
tery is  used  nott  more  than  two  cells  are  usually  placed  in 
series.  Figs.  426-429  show  various  arrangements  of  this 
type  in  general  use  for  track  circuits.  The  following  table 
shows  the  maximum  current  flowing  under  certain  given  coudi- 


cells  are  placed  in  series  the  internal  resistance  is  increased 
proportionately  to  the  number  of  cells ;  with  two  cells  it  is 
twice  as  much,  three  cells  three  times  as  much,  etc. 

The  electrical  characteristics  of  the  various  arrangements  are 
shown  in  the  table.  Their  mechanical  characteristics  will  now 
be  considered.  Fig.  422  is  seldom  used,  for  the  reason  that 
should  the  jar  break  or  any  other  accident  happen  to  the  cell, 
the  circuit  wou'd  fail  to  operate.  Fig.  426  ("A"),  two  cells  in 
multiple  or  parallel,  is  the  usual  arrangement.  It  guards  against 
failures,  as  the  chance  of  accident  to  both  cells  at  the  same 
time  is  remote.  Also  the  cells  can  be  renewed  alternately, 
thereby  assuring  a  uniform  output  of  the  battery  as  a  whole. 
Fig.  429  ("D"),  three  cells  in  parallel,  is  a  further  development 


C1        A  D  B 


.3 


6  .7  .8 

Current -in  Amperes. 


Fig.  430.     Performance  of  Track  Circnit  Battery  Under  the  Four  Arrangements  Shown  in  Figs.  426-429. 


tions.  In  this  table  1.079  volts  is  taken  as  the  maximum  initial 
E.  M.  F.  of  a  gravity  cell,  and  two  ohms  as  the  minimum  inter- 
nal resistance. 

Maximum  current  (in  milli-amperes). 

Through  Through 

Track  shunted.    9-ohm  relay.    3% -ohm  relay. 

Fig.    422 

Fig.   426 

Fig.  429 

Fig.    423 

Fig.   427 

Fig.   428 

Fig.   425 

Fig.    124 

For    the    purposes    of 


539.5 

98.09 

196.18 

1,079.0 

107.9 

239.78 

1,618.5 

111.62 

258.96 

539.5 

1  66.0 

287.73 

719.33 

179.88 

332.0 

1,079.0 

196.18 

392.36 

1,294.8 

202.31 

417.68 

1,618.5 

208.84 

446.48 

the   above 

table   the 

resistance    of 

the 

of  Fig.  4^26  ("A").  It  also  secures  a  slightly  lower  internal  re- 
sistance with  consequent  increased  output.  Fig.  423,  two  cells 
in  series,  like  Fig.  422,  i.;  rarely  used,  and  for  the  same  reason 
Fig.  427  ("B"),  two  cells  in  multiple  with  one  ui  series,  is 
rather  liable  to  failure,  but  has  electrical  advantage,  as  can  he 
seen  from  the  table.  With  this  arrangement  it  is  customary  to 
rotate  the  cells  from  one  place  in  the  battery  to  another  at  the 
times  of  inspection  and  renewal.  Fig.  428  ("C")  four  cells  in 
series  multiple,  is  frequently  used  for  long  or  wet  sections  ;  it 
will  be  noted  that  it  is  a  development  of  Figs.  426  ("A")  and 
423.  Fig.  425  is  a  development  of  Fig.  427  ("B"),  and  Fig. 
424  of  Fig.  428  ("C"). 

The  curves  in  Fig.  430  show. -at  the  left,  the  amount  of  cur- 
rent, in  milli-amperes,  that  passes  through  a  four-ohm  relay  for 
each  of  the  connections,  A,  B,  C  and  D,  with  the  track  resist- 


Figs.  431-438 


BLOCK    SIGNALS. 


49 


Fig.  431.     Wedged    Switch   in   Track    Circuit.      (Switch  rail  separated  by  wedges  from  electrical  connection  with 

main  rail.) 


Fig.  432.     Switch    in    Track    Circuit;    One    Rail    Cut   Out. 


Fig.  433.      Insulated    Switch,  with    Siding    Rails    Electrified    to    Fouling    Point,  D  E. 


Fig.  434.     Insulated    Switch,    with    Fouling    Protection.      Chicago    &    North-Western. 


435-     Siding    Crossover    in    Track    Circuit.      Chicago    &    North-Western. 


Fig.  436.     Main    Line    Crossover   in   Track    Circuit    (Left-Hand    Running).     Chicago   &  North-Western. 


Fig.  437.     Protection  for  Switch  in  Main  Track  and  Derail  in  Siding. 


Fig.  438.     Protection  for  Switch  and  Siding  Derail;  Siding  Rail  in  Series. 


BLOCK    SIGNALS. 


Figs.  439-441 


ance  varying  from  0  to  4  ohms.  The  curves  to  the  right  show 
the  total  amount  of  current  in  the  circuit  for  each  of  the  four 
connections  with  the  same  range  of  roadway  resistance.  It  is 
evident  that  the  variation  in  the  amount  of  current  is  not  so 
great  when  the  roadway  resistance  is  high.  When  this  is  the 
case  the  connection  that  will  furnish  the  least  amount  of  cur- 
rent that  will  operate  the  relay  is  the  most  desirable,  since  it 
Is  tha  most  economical.  Inasmuch,  however,  as  the  average 
track  circuit  is  subject  to  conditions  which  reduce  its  resist- 
ance at  times,  the  particular  arrangement  that  will  give  the 
maximum  of  current  when  the  leakage  in  the  section  is  con- 
sidered is  the  one  that  should  be  used.  It  is  seen  that  con- 
nection A  gives  the  least  amount  of  current  with  a  high 
roadway  resistance,  and  its  volume  increases  to  a  total  of  one 
ampere  when  the  roadway  resistance  is  the  lowest  possible. 
Connection  B  gives  more  current  under  dry  conditions,  but 
when  the  roadway  resistance  drops  the  volume  or  current  is 
not  increased  as  much  as  that  given  by  A.  C  gives  more  current 
than  either  A  or  B  under  dry  conditions,  and  shows  a  better 


circuits,  one  controlled  by  the  other.  Fig.  410  shows  a  train  in 
the  first  section.  The  relay  R'  of  the  second  section  breaks 
and  shunts  the  circuit  of  the  first  section  when  the  train  Is  in 
the  second  (Fig.  411).  As  with  the  single  track  circuit,  re- 
sults are  practically  the  same  whichever  way  the  train  is  mov- 
ing. It  should  be  noted  that  the  shunting  effect  of  the  back 
contact  point  of  relay  R'  is  applied  to  the  track  and  not  to  the 
battery.  This  is  to  shunt  out  any  foreign  current  that  may 
have  leaked  into  the  section  and  would  be  liable  to  energize 
the  relay  It.  It  also  prolongs  the  life  of  battery  B. 

The  track  circuits  above  considered  were  normally  closed. 
Normally  open  circuits  are  also  used  to  a  limited  extent. 
Fig.  412  shows  such  a  circuit.  Here  the  relay  is  normally  de- 
energized,  as  there  is  no  connection  between  the  rails.  The 
presence  of  a  train  on  the  circuit,  Fig.  413.  picks  up  the 
armature  opening  or  closing  control  circuits  through  its  contact 
points.  Current  flows  from  positive  side  of  battery  to  one  rail, 
through  the  wheels  and  axles  of  the  train  to  the  other  rail, 
through  the  relay  and  back  to  the  battery.  This  kind  of  circuit 


Operated  by  Sw/fch  A 

Fig.  439.     Transposition    and    Protection    for    Two    Switches. 


Fig.  440.     Protection   for  Main   Line   Crossover  and   Slip  Switch. 


Fig.  441.     Track   Circuit   for   Main   Line   Crossover.     Illinois   Central. 


performance  than  the  others  when  the  roadway  resistance  is 
low.  D,  for  the  average  condition,  seems  to  be  the  best  of  the 
four,  as  it  shows  a  more  economical  output  under  dry  condi- 
tions, and  takes  care  of  the  low  resistance  conditions  with  a 
much  greater  volume  of  current  than  the  other  arrangements. 

The  use  of  secondary  or  storage  battery  has  been  referred  to. 
When  this  is  used  it  is  necessary  to  insert  a  resistance  in  one 
or  both  battery  leads  to  restrict  the  flow  of  current  and  pre- 
vent the  battery  from  becoming  exhausted  by  the  passage  of 
one  train,  and  otherwise  injured  by  over-discharge. 

Where  it  is  necessary  to  control  signaling  apparatus  by 
track  circuits  over  such  a  length  of  track  that  one  circuit  would 
not  work,  two  or  more  circuits  are  employed.  The  control  cir- 
cuits may  be  broken  through  the  relays  of  the  successive  track 
circuits,  or  "cut  sections"  may  be  introduced.  Fig.  409  shows 
this  latter  arrangement,  which  consists  of  two  adjacent  track 


is  used  principally  for  annunciators.  Here  only  one  rail  In 
each  part  of  the  circuit  is  insulated,  but  this  does  not  in  any 
way  affect  its  operation.  A  train  on  any  track  between  the 
insulated  joints  will  complete  a  circuit  as  in  Fig.  413.  In 
normally  open  track  circuits  the  resistance  of  the  relay  should 
be  lower  than  in  normally  closed.  Their  use  is  necessarily 
limited  to  track  sections  of  a  few  rail  lengths  only  ;  in  longer 
sections  the  low  insulation  resistance  from  rail  to  rail  would 
allow  the  flow  of  enough  current  to  held  up  the  relay  after  a 
train  had  passed  out  of  the  section.  Gravity  battery  should 
not  be  used  unless  the  traffic  is  very  heavy,  as  a  gravity  cell 
soon  deteriorates  and  becomes  inoperative  on  an  open  circuit. 
The  use  of  normally  open  track  circuits  is  also  limited  on 
account  of  the  fact  that  there  is  no  certainty  that  the  relay 
will  pick  up.  Any  failure  of  the  apparatus,  such  as  a  broken 
rail,  exhaustion  or  breakage  of  the  battery  cell,  or  breakage  at 


Figs.  442-455 


BLOCK    SIGNALS. 


any  of  the  wires,  will  render  the  apparatus  Inoperative.  Such 
fa'lures  arc  not  readily  detected,  as  they  merely  maintain  the 
apparatus  in  its  normal  condition.  With  a  normally  closed  cir- 
cuit the  reverse  is  true.  Here  any  failure  will  be  almost  imme- 
diately detected,  and  will  be  on  the  side  of  safety. 

Figs.    414   and   115   show   the  same  circuits   as   Figs.   406   and 
412,   except   that   only   one    rail   is   Insulated.      These  are  some- 


Fig.  416  is  a  special  arrangement.  A  normally  open  track 
circuit  is  placed  within  the  limits  of  a  normally  closed  circuit. 
This  shows  one  advantage  of  insulating  only  one  rail.  The  un- 
insulated rail  is  common  to  both  circuits,  and  the  necessity  of 
a  second  "jumper"  to  carry  one  circuit  past  the  other  is  avoided. 
Such  an  arrangement  might  be  used  when  it  is  necessary  to 
announce  a  train  from  some  point  within  a  signal  track  circuit. 


Fig.    442.     Common    Location    of    Insulated    Joints    at 
Switch. 


Fig.  443.Switchbox  Arranged   to   Shunt  Track   Circuit. 


rig.  444.     Wiring  when   Battery   is   Located  at  Switch. 


Fig.  445.     Wiring  when  Relay  is  Located  at  Switch. 


Fig.  446.     Shunt  Circuit. 


Fig.  447.     Series  Fouling  Circuit. 


Fig.   448.     Alternate    Circuit   for   Series    Fouling. 


TEE 


Fig.  450.     Both  Turnout  Rails  in  Series. 


Fig.   449.     Series    Fouling,    Changing    Polarity. 


JB, 

Fig.  452.     Relay  Located  Near  Switch. 


Fig.  451.     Battery   Located  Just  Ahead   of   Switch 
Points. 


Fig.  453.     Double  Turnout. 


454.     Lap    Switch. 

Figs.   442-455. 


Fig.  455.     Wiring  for  Interlocked  Switch. 
Track    Circuit   Wiring  at   Switches. 


times  termed  "single  rail"  circuits.  Installations  of  this  kind 
are  made  to  avoid  the  expense  of  two  insulated  joints  or  where 
one  rail  is  needed  for  another  circuit.  Such  track  circuits  are 
more  liable  to  failure  than  those  having  both  rails  insulated, 
for  the  reason  that  the  breakdown  of  one  insulated  joint  will 
extend  the  circuit  beyond  its  proper  limits  and  cause  inter- 
ference with  neighboring  circuits  and  premature  or  extended 
shunting  of  the  relay,  due  to  the  presence  of  a  train  beyond 
the  insulated  joints. 


In  Figs.  417  and  418  is  shown  a  track  circuit  in  which  the 
direction  or  "polarity,"  as  well  as  the  presence  of  current,  is 
made  use  of  at  the  relay.  By  this  means  two  separate  func- 
tions may  be  performed  by  one  track  circuit,  provided  that 
the  first  or  principal  function,  actuated  by  the  presence  (or 
absence)  of  current,  does  not  interfere  with  the  secondary  func- 
tion, actuated  both  by  the  presence  of  current  and  its  polarity. 
For  example,  in  a  two-arm  (home  and  distant)  automatic  signal 
the  borne  signal  is  controlled  by  its  immediate  track  circuit, 


BLOCK    SIGNALS. 


Figs.  456-471 


Fig.  456.     Wiring  for  Interlocked  Switch. 


Fig.  457.     Wiring  for  Junction  Point. 


Fig.  458.     Wiring  for  Interlocked  Switch. 


Fig.  459.     Crossover  Wiring  to  Protect  One  Track. 


Fig.  460.     Crossover  Wiring  to  Protect  Both  Tracks. 


Fig.  461.     Series  Fouling  Reversing  Polarity. 


C/rcuife 
Fig.  462.     Independent  Track  Circuit  for  Crossover. 


Fig.  463.     Wiring  for  Two  Tracks  Diverging  to  Three. 


Fig.  464.     Wiring  for  Two  Tracks  Diverging  to  Three. 


Fig.  465.     Wiring  for  Entrance  to  Center  Passing 
Track. 


Fig.  466.     Wiring  for  Gauntleted  Tracks.     Incomplete  Fig.  467.     Gauntleted  Tracks  Properly  Protected. 

Protection. 

Figs.   456-467.     Protective   Wiring. 


A  V 


\\ 


Fig.  468. 


Track     Circuits     Through     Crossing;     Two       Fig.  469.     Transposition  of  Track  Circuit  at  Crossing. 
Rails    Continuous. 


Fig.  470.     Track  Circuits  Through  Crossing;  One  Rail       Fig.  471.     Track     Circuits     Through     Crossing;     Four 
Continuous.  Jumpers. 


Figs.  472-478 


BLOCK    SIGNALS. 


53 


while   the   distant   must   be   controlled  by   this  circuit  and  the 
position  of  the  next  home  signal  In  advance. 

In  place  of  the  ordinary  track  relay,  one  of  special  design 
called  a  polarized  relay  Is  used.  Such  a  relay  Is  constructed 
like  an  ordinary  track  relay,  except  for  the  addition  of  a  polar- 
ized armature.  In  its  simplest  form  this  armature  would  con- 
sist of  a  permanent  magnet,  one  extremity  of  which  would  be 
free  to  swing  between  the  pole  pieces  of  the  electro-magnet. 
As  like  magnetic  poles  repel  each  other,  and  unlike  attract,  and 


This  Is  actuated  by  any  desired  means,  such  as  a  lever,  signal 
arm,  etc.  Current  flows  from  positive  side  of  battery  through 
left-hand  arm  of  pole  changer,  through  lower  rail,  relay,  upper 
rail,  right-hand  arm  of  pole  changer,  back  to  battery.  The 
polarized  armature  carrying  contacts  is  deflected  to  the  left 
and  makes  contact  with  the  front  point.  With  the  pole  changer 
reversed  (Pig.  418),  current  flows  from  positive  side  at  bat- 
tery through  the  left  arm  of  pole  changer,  upper  rail,  relay, 
lower  rail,  right-hand  arm  of  the  pole  changer,  back  to  battery, 


SIP/MG  SW/TCH. 
Figs.  472-474.     Switch    and    Crossover    Protection.      New    York    Central    &  Hudson  River. 

A 


'Attached  to 
normaf/y  c/osecf  po/nf. 


Contacts  to  c/ose  when 
&IV//C/T  /s.  cperr  *:  inch . 


Defer// 


^L.x'-A'o.  8  /rorr  Mr* 


Fig.  475.     Switch  Wiring  and  Fouling  Protection.     Southern   Pacific. 


1 


Fig.  476.     Protection     Against     Foreign     Currents;     "Single 
Rail"  Track  Circuits;  Jumpers  at  Each  End. 


Fig.  477.     Foreign     Current     Protec- 
tion;  Isolated   Two-Rail  Track 
Circuit. 


•^   ~    r 

<  £/ecfr/c  /?.  St. 

~\      f  r 



| 

5feerm/?.# 

= 

p 

1   ri 

_ 

3 

-  

f 

Stl 

J 

f 

:k_ 

<- 

^//Ji/mpers  ancf  Ta/os 
//&.&.  ffi/Aber  Core/-ecS  Mre. 

—  SOQOOO  C.  M.  Cab/e 

Fig.  478. 


Bonding  at  Crossing  of  an  Electric  Railroad. 
Chicago   &   North-Western. 


as  a  reversal  of  the  direction  of  flow  of  current  in  the  colls 
of  an  electro-magnet  reverses  the  polarity  of  the  magnet,  It 
can  readily  be  seen  that  with  the  track  circuit  flowing  in  one 
direction,  the  polarized  armature  would  be  attracted  to  one 
pole  of  the  magnet,  and  vice  versa.  Change  of  direction  In 
the  track  circuit  current  Is  effected  by  the  pole  changer  shown. 


and  the  polarized  armature  is  deflected  to  the  right,  making 
contact  with  the  back  point.  It  should  be  noted  that  In  both 
cases  the  neutral  or  ordinary  armature  is  attracted  as  in  an 
ordinary  track  circuit.  Thus  a  circuit  entirely  separate  from 
one  through  the  neutral  points  can  be  controlled  from  beyond 
the  track  circuit,  by  means  of  the  track  circuit  Itself,  without 
interfering  with  the  one  through  the  neutral  points. 

Figs.  419  and  420  show  how  a  "cut  section"  may  be  intro- 
duced Into  a  polarized  track  circuit.  Here  a  polarized  relay  is 
uned  at  the  end  of  the  right-hand  section  to  reverse  the  polarity 
of  the  circuit  for  the  left-hand  section.  This  relay  acts  exactly 
as  above  described  with  relation  to  the  pole  changer.  Its  polar 
ized  armature  fingers  are  made  to  take  the  place  of  a  mechan 
leal  pole  changer,  thus  repeating  the  action  of  the  mechanical 
pole  changer  to  the  left-hand  section.  Fig.  419  shows  the  nor- 
mal condition  of  the  two  circuits ;  Fig.  420,  their  condition 
when  the  mechanical  pole  changer  Is  reversed.  It  should  be 
noted  that  the  neutral  point  at  the  cut  section  relay  breaks  and 
shunts  the  circuit  in  the  rear  just  as  In  an  ordinary  cut  sec- 
tion (Figs.  409-411)  to  transmit  the  shunting  effects  of  a  train 
in  the  right-hand  section  to  the  other. 

Where  switches  occur  in  a  track  circuit  special  means  must 
be  employed  to  prevent  short  circuiting  through  the  switch  rods, 
and  leakage  to  the  turnout  rails.  Fig.  431  shows  the  simplest 
method  of  accomplishing  this.  Wedges  are  placed  under  the 
normally  open  point ;  these  wedges  are  not  in  contact  with  the 
main  track  rail  or  the  tie  plates.  They  raise  the  switch  point 
off  the  tie  plates  when  it  is  open,  but  allow  it  to  rest  on  them 


54 


BLOCK    SIGNALS. 


Figs.  479-483 


when  closed.  Two  insulated  joints  are  installed  in  the  turnout 
tracks,  one  just  behind  the  heel  of  the  frog  and  the  other  at 
the  end  of  the  stock  rail.  This  method  is  objectionable,  for 
any  metallic  substance  lodging  between  the  wedges  and  tie 
plates  will  cause  a  short  circuit. 

Another  method  is  shown  in  Fig.  432.  One  rail  is  cut  out 
of  the  circuit  and  a  "jumper"  used  to  carry  the  current  around. 
The  objection  to  this  is  that  the  dead  rail  might  break  and  no 
protection  be  afforded.  Also  it  requires  two  insulated  joints 
in  the  main  track,  which  is  undesirable  (becausje  insulated 
joints  in  main  track  are  somewhat  expensive  to  maintain),  and 
should  be  avoided  when  possible. 

The  most  usual  method  is  shown  in  Fig.  433.  Here  the 
switch  rods,  A,  are  insulated  and  the  insulated  rail  joints  dif- 
ferently arranged.  One  is  placed  at  C  as  above;  another  at 
B  in  switch  rail  between  main  track  rails,  and  two  mothers,  D 
and  E,  at  the  fouling  point  of  the  turnout.  The  switch  points 
are  bonded  to  the  stock  rails  to  insure  shunting  by  a  pair  of 
wheels  on  any  part  of  the  track.  For  the  same  reason  the 


switch,  however,  occurs  in  the  siding,  and  this  is  merely 
shunted  in  as  far  as  the  main  line  fouling  point.  Two  wires 
are  used  for  the  jumper  so  as  to  give  protection  should  one 
break.  These  are  soldered  to  separate  bond  wires  at  -a  con- 
venient joint  (Detail  A),  because  if  they  were  tapped  into  the 
main  track  rail  at  separate  points  and  the  rail  should  break 
between  them,  there  would  be  no  protection  against  this  broken 
rail.  A  detail  of  the  frog  bonding  is  also  shown.  This  guards 
against  a  broken  frog  to  a  certain  extent.  Protection  against 
an  ci)°n  switch  is  secured  through  the  switch  instrument  or 
"switch  box"  shown  in  enlarged  detail.  The  lever,  moved  by 
the  rod  attached  to  the  normally  closed  point  of  the  switch, 
brings  the  upper  set  of  springs  into  contact  with  a  similar  set 
below  them  (not  shown)  when  the  point  is  open  14  inch  or 
more.  The  upper  set  of  springs  are  connected  by  two  wires  to 
one  rail  of  the  main  track,  and  the  lower  set  to  the  other  rail, 
as  shown.  When  the  two  sets  of  springs  come  into  contact 
the  result  is  the  same  as  the  presence  of  a  train,  namely,  a 
short  circuit.  Four  upper  and  four  lower  springs  are  used  in 


Figs.  479-483.     Location  of  Insulated  Joints  and  Trunking  for  Siding,  Main  Line  Crossover  and  Passing  Track 

Crossover.     Atchison,   Topeka    &  Santa    Fe. 


upper  main  line  rail  is  connected  to  the  lower  turnout  rail  by 
the  "jumper,"  F-G.  This  insures  a  shunt  should  a  pair  of 
wheels  stand  anywhere  within  the  fouling  point.  It  is  desir- 
able to  have  this  jumper  connect  at  the  point  G,  midway  be- 
tween the  insulated  joints,  to  insure  maximum  amount  of  live 
track  in  case  of  a  broken  rail  between  C  and  B.  If  this 
"jumper"  were  not  used  and  the  insulated  joint,  C,  on  the 
turnout  dispensed  with,  both  turnout  rails  would  be  of  the 
same  polarity  and  no  shunt  would  be  effected.  The  joints,  B 
and  C,  should  be  opposite  each  other  in  order  to  avoid  a  dead 
section  of  track  between  them. 

Fig.  434  shows  a  method  of  guarding  against  a  broken  wire 
or  rail  within  the  fouling  distance  on  the  turnout.  Here  an 
insulated  joint  is  placed  in  the  main  track  near  the  switch, 
and  a  jumper  run  from  each  side  of  it  to  the  fouling  section 
of  the  side  track  rail.  This  puts  the  turnout  rails  in  series 
with  the  main  track  and  a  broken  wire  or  rail  would  open  the 
circuit.  No  provision  is  made  for  similar  protection  of  the  inner 
turnout  rails,  however.  In  Fig.  435  is  shown  how  the  above 
protection  is  applied  to  a  siding  crossover.  Fig.  436  shows  the 
same  applied  to  a  main  line  crossover. 

All  the  above  methods  of  running  track  circuit  through 
switches  show  no  protection  against  an  open  switch.  Fig.  475 
shows  how  such  protection  is  usually  provided.  The  wiring  of 
the  track  is  the  same  as  shown  in  Fig.  433.  An  additional 


multiple,  to  guard  against  failure  of  any  one  pair  and  to  pro- 
vide a  low  resistance  circuit. 

Fig.  437  shows  a  slightly  different  method  of  arrangement, 
with  the  switch  box  shown  dlagrammati'cally.  The  track  circuit 
is  transposed  and  the  contact  springs  shunt  the  circuit  as  above, 
hut  around  the  insulated  joint  instead  of  across  the  track.  In 
this  figure  is  also  shown  a  switch  box  worked  by  a  siding  derail 
which  shunts  the  main  track  rails  when  the  derail  is  closed. 
The  main  track  is  shunted  rather  than  the  siding,  because  a 
broken  wire  or  rail  in  the  siding  would  render  the  shunt  inop- 
erative. 

Fig.  438  illustrates  a  method  of  switch  protection  'Which  is 
somewhat  elaborate.  Under  normal  conditions  current  flows 
from  battery  through  upper  rail  to  insulated  joint,  thence 
through  jumper,  upper  pair  of  switch  box  contacts,  through  two 
middle  right-hand  switch  bos  binding  posts,  through  jumper, 
outside  siding  rail,  through  derail  switch  box  in  same  manner 
as  first  switch  box,  to  upper  main  track  rail,  through  relay, 
back  on  lower  main  track  rail  to  battery.  When  either  switch 
or  derail  is  reversed  the  run  around  jumper  circuit  is  opened 
and  the  relay  shunted  by  the  switch  box.  These  switch  boxes 
are  provided  with  two  normally  closed  and  two  normally  open 
contacts  instead  of  four  normally  open,  as  in  previous  exam- 
ples. In  this  figure  a  control  circuit  is  shown  carried  through 
one  pair  of  closed  contacts  in  each  box.  This  circuit  would  be 


Figs.  484-486 


BLOCK    SIGNALS. 


55 


broken  with  cither  switch  or  derail  reversed.  This  represents 
a  line  wire  controlling  the  signal  and  is  provided  as  an  addi- 
tional precaution.  A  switch  indicator  is  also  shown  at  the 
derail. 

Fig.  439  shows  two  switches  close  together.  Hm>  the  track 
circuit  is  transposed  by  means  of  a  run  around  jumper  between 
the  switches.  Current  passes  from  upper  rail  right-hand  side, 
through  jumper  to  lower  rail  left-hand  side  and  from  upper 
rail  left-hand  side  through  frog,  switch  point,  to  lower  rail 
through  bond  wires,  also  in  parallel  in  a  similar  manner  through 
the  other  frog  and  switch  point.  The  switch  boxes  shunt  the 
circuit.  No  switch,  boxes  are  used  at  the  derail  and  siding 
switch,  because  these  are  controlled  mechanically  from  the  main 
line  switches.  Many  roads,  however,  use  switch  boxes  even  at 
both  ends  of  pipe  connected  or  plunger  locked  switches  and 
ill-rails  as  an  extra  precaution.  Fig.  440  shows  a  similar  arrange- 
ment as  applied  to  a  crossing  with  a  single  slip  switch  and 
crossover  between  two  main  tracks.  All  the  switch  boxes  must 
shunt  both  main  tracks  because  with  any  switch  open  a  train 
might  foul  both  tracks. 

Fig.  441  illustrates  what  is  perhaps  the  highest  development 
of  crossover  protection.  Plere  the  rails  of  the  crossover  are 
made  into  a  separate  track  circuit  whose  relay,  when  de-ener- 
gized, shunts  both  main  line  circuits.  The  relay  may  also  be 
made  to  break  one  or  more  signal  control  circuits,  as  was  done 
by  switch  boxes  in  Fig.  438.  The  switch  box  wiring  is  the 
same  as  that  illustrated  in  Fig.  475,  except  that  one  pair  of 
springs  in  each  box  is  normally  closed  and  breaks  the  crossover 
track  circuit  with  either  switch  open.  It  is  obvious  that  a 
broken  crossover  rail  will  cause  the  shunting  of  both  main  line 
circuits,  also  that  a  single  engine  or  car  standing  on  the  cross- 
over, with  both  switches  closed,  would  produce  the  same 
result. 


Figs.  472-474  show  the  New  York  Central  standard  circuits 
for  switch  protection.  They  are  similar  to  Fig.  475. 

Where  one  track  crosses  another  at  grade  means  must  be  pro- 
vided to  carry  the  track  circuits  through  or  around  the  crossing 
frogs.  Figs.  468-471,  inclusive,  illustrates  how  this  may  be 
done.  In  Fig.  468  the  horizontal  tra^c  circuit  goes  through  and 
the  other  is  carried  around  the  frogs  by  jumpers.  In  Fig.  469 
there  Is  only  one  circuit,  which  Is  transposed  at  the  frog. 
Fig.  470  is  used  instead  of  Fig.  468  when  the  crossing  is  at  or 
near  a  right  angle  and  insulation  cannot  easily  be  placed  in  the 
frog  rails.  Fig.  471  is  a  development  of  Fig.  470,  and  is  the 
most  usual  method;  nevertheless,  In  order  to  guard  against 
broken  rails  or  frogs,  it  is  desirable  to  have  as  little  dead  track 
as  possible. 

Fig.  476  shows  how  single  rail  circuits  (see  Figs.  414-416) 
may  be  used  where  there  is  f6reign  current  that  might  inter- 
fere with  a  two-rail  circuit.  The  cross  bonding  beyond  the 
track  circuit  does  away  with  any  difference  of  potential  which 
might  otherwise  exist  between  the  rails,  and  the  foreign  current 
is  carried  past  through  the  lower  rail,  which  is  made  common 
to  all  the  track  circuits.  Fig.  477  shows  another  method  of 
accomplishing  the  same  results,  which  may  be  used  with  a 
short  isolated  circuit.  While  allowing  both  rails  to  be  used 
for  a  track  circuit,  the  cross  bonds  are  installed  as  above, 
and  foreign  current  is  carried  past  through  a  jumper  connect- 
ing these  bonds.  In  Fig.  478  is  shown  an  electric  railroad 
crossing  two  tracks  of  a  steam  road.  The  track  circuits  of  the 
steam  road  are  carried  around  as  in  Fig.  471,  but  to  avoid  leak- 
age as  far  as  possible  the  trolley  track  is  cross  bonded  on  each 
side  of  the  frogs  to  prevent  any  difference  of  potential  that 
might  otherwise  exist  between  the  rails,  and  all  members  of 
the  frogs  are  bonded  together  and  to  the  heavy  central  jumper 
connecting  the  cross  bonds. 


CONTROL  CIRCUITS 


NORMAL    CLEAR.       LINE    CONTROL. 

In  Fig.  484,  if  a  car  or  train  occupies  the  track  between  the 
insulated  joints,  J,  J,  it  shunts  the  relay  R.  This  allows  its 
armature  to  drop,  opening  the  local  circuit,  de-energizing  the 
magnet,  which,  when  energized,  holds  the  signal  in  the  clear 
position. 

In  Fig.  485  the  home  arms  are  controlled  as  shown  in  Fig. 

J  *' 


S' 


] 


Fig.  484.     Arrangement  of  Track  Circuit  and  Connec- 
tions for  Normal  Clear  Automatic  Block  Signals. 


484.  Each  home  arm,  when  moved,  moves  its  two  circuit  con- 
trollers; one  to  control  the  circuit  to  its  distant  signal,  one 
block  in  the  rear,  and  the  other  to  control  the  distant  arm  on 
its  own  post.  For  control  of  the  distant  one  block  back,  cur- 
rent flows  from  the  main  battery  through  the  second  contact 
on  the  track  relay,  to  the  circuit  controller,  and  thence  over 
the  line  to  and  through  one  of  the  controllers  at  the  signal  in 
the  rear  and  to  the  electro-magnet  there  controlling  the  distant 
arm;  thence  back  over  the  common  return  wire.  The  control 
by  a  home  signal  of  the  distant  arm  on  its  own  post  (which 
primarily  is  controlled  by  the  home  arm  one  block  in  advance), 
is  to  avoid  an  apparently  inconsistent  indication  when  the  home 
arm  is  at  stop,  while  the  distant,  so  far  as  its  own  section  is 
concerned,  might  be  clear.  The  home  arm  can  put  the  distant 
to  caution,  but  cannot  clear  it,  except  when  the  home  arm  in 
advance  is  clear.  Switch  indicators  are  shown  connected  in 
series,  operated  by  contacts  on  track  relays. 

Fig.  486  is  the  same  as  Fig.  485,  but  with  each  home  signal 
controlled  by  the  track  relay  of  two  blocks  in  advance,  instead 
of  only  one.  Thus  the  home  signal  at  the  extreme  left  of  the 
drawing  is  controlled  (1)  by  its  own  track  relay,  and  (2)  by  the 
track  relay  of  the  block  in  advance. 


Fig.  485.     Arrangement  of  Circuits  for  Normal  Clear  Automatic  Signals;  Line-Wire  Control  for  Distant  Signal. 


Fig.  486.     Normal  Clear,  Line-Wire  Distant  Control  and  Full-Block    Overlap.      Pennsylvania    Railroad. 


BLOCK  SIGNALS. 


Figs.  487-489 


90    CONTROL 
45°  CONTROL 


CIRCUIT    BREAKER 
ON    SIGNAL  1. 
CLOSED  AT  90C 
CLOSED  45°-90c 


CUT  SECTION 


— •     'I 


90  RELAY  SIGNAL  1 


IND.  C  CONTROL  AND 
90   RELAY  SIGNAL  1 


COMMON 


INDICATOR   C  CONTROL 


Fig.  487. 


Circuits   for    Normal    Clear,    Three-Position    Signals.      Northern   Pacific   Railroad. 

Signal  Company. 


INDICATOR  C  CONTROL 

General   Railway 


Fig.  487  shows  circuits  typical  of  double-track  installation 
on  the  Northern  Pacific.  The  signals  are  G.  R.  S.  Model  "2A," 
three  position,  upper  quadrant,  low  voltage  d.  c.  control.  The 
track  circuits  are  relayed  through  cut  sections,  being  shunted 
on  the  opening  of  any  switch  in  the  given  sections  by  the 
switch  circuit  controller.  This  permits  the  use  of  a  local 
circuit  for  the  control  of  the  45-deg.  position  of  the  signal.  The 


signal    and    a   stop    indication    at   the   signal    for    the   block    In 
which  the  switch  is  located. 


NORMAL    CLEAR POLARIZED    LINE    CONTROL. 

Fig.  488  shows  diagrammatically  the  circuits  used  in  con- 
nection with  an  installation  of  normal  clear,  three-position, 
upper  quadrant  signals  on  a  single-track  division  of  the 


Fig.    488.      Circuits    for    Normal    Clear,    Three-Position    Signals.       Polarized    Line    ControK       Northern     Pacific 

Railroad.     General  Railway  Signal  Company. 


circuit  for  the  control  of  the  90-deg.  position,  in  every  case, 
is  broken  through  the  circuit  breaker  on  the  signal  in  ad- 
vance, energy  being  obtained  from  the  45-deg.  control  wire  of 
that  signal.  The  control  for  the  indicators  is  carried  far 
enough  back  so  that  warning  is  given  at  the  switch  when 
a  train  is  approaching  the  second  signal  in  the  rear ;  if  the 
switch  is  open,  the  train  is  given  a  caution  indication  at  that 


Northern   Pacific.     The   signals   are   G.    R.    S.    Model    "2A,"    low 
voltage  d.  c.  control. 

In  this  circuit,  the  signal  is  controlled  by  a  polarized  relay, 
the  45-deg.  control  being  taken  through  the  neutral  contacts 
only  while  the  90-deg.  control  is  taken  through  both  the  neutral 
and  polarized  contacts.  The  energy  for  this  line  relay,  in 
every  instance,  is  taken  from  the  battery  of  the  signal  In 


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Fig.  489. 


Circuits  for  Normal  Clear  Automatic  Signals  on   Single  Track;   Maximum  Distance  for   One   Pair  of 

Staggered  Signals.     Southern   Pacific. 


Fig.  490 


BLOCK  SIGNALS. 


57 


advance  through  pole  changer  contacts  operated  by  the  mech- 
anism of  that  signal,  the  arrangement  being  such  that  the 
positive  side  of  the  battery  Is  connected  to  the  line  when  the 
signal  is  in  the  90-deg.  position,  and  the  negative  to  the  line 
when  the  signal  is  in  the  45-deg.  position.  The  relay  is 
arther  controlled  through  the  front  contacts  of  all  track 


7  on   Opposite   Page. 

When  the  characteristics  of  the  signal  control  are  such  that 
nothing  is  to  be  gained  by  operating  through  three  positions 
(see  signal  5,  Fig.  488),  only  two  indications,  the  0  and  90-deg., 
are  given.  This  is  accomplished  by  joining  the  45  and  90-deg. 
control  wires  and  taking  them  in  series  through  the  neutral  and 
polarized  contacts  of  the  controlling  line  relay. 


RELAY    CONTROL  SIG.  3 


Fig.  488.     Continued  from   Fig.  488  on   Opposite   Page. 


relays  and  through  normally  closed  contacts  of  all  switches 
within  the  section  governed  by  the  signal  in  question.  The 
signal  is  thus  controlled  in  the  90-deg.  position  through  the 
next  signal  in  advance  at  45  or  90  deg.  and  in  the  45-deg. 
position  through  the  track  relays  of  the  sections  within  the 
control  of  the  signal  in  question. 


It  will  be  seen  that  on  account  of  the  type  of  overlap  used, 
two  trains  running  in  opposite  directions  between  stations 
cannot  come  closer  together  than  a  block,  of  3,000  ft.  without 
encountering  a  stop  signal,  and  will,  in  practically  every  In- 
stance, have  been  prepared  for  such  stop  signal  by  receiving 
a  caution  Indication  from  the  previous  signal. 


Fig.  490.     Circuits  for  Normal  Clear  Automatic  Signals   on  Single  Track  between  Stations;  Minimum  Distance 

for    Staggered    Signals.      Southern    Pacific. 


BLOCK  SIGNALS. 


Figs.  491-494 


Fig.    491. 


\30o'?\    30oo-    I    sooo'-    i  2000'-^    jooo'-     I     3ooo'-  \3oo'-\  Home  S/gna/  Con  fro/  L/m/'fs 

K — T T T- 4 -t -H- \  -_Distanf  . 

Switch  /nd/cafora          » 

Diagram    of    Clear    Automatic    Signals    for    Single    Track    Showing    Control    Limits    of    Apparatus, 
as    Used    on    the    Ulster    &    Delaware.      The    Union    Switch    &    Signal    Company. 


Fig.    492.     Diagram    of    Typical    Circuits    for    Signals    Shown  in  Fig.  491.    The  Union  Switch  &  Signal  Company. 


t-y 


/*/-*/«.  ^   ! 


teoo 


493-     Circuits  for  Normal  Clear  Automatic  Signals    on     Single    Track,    Alternative     Arrangement,     Where 
Section    between    First    Staggered    Signal   and    Station   Distant  Signal  is  too  Great  for  One 

Track    Circuit.      Southern    Pacific. 


SOO 


Station. 


Fig.   494.      Circuits   for    Normal    Clear    Automatic    Signals    at    Stations    on    Single    Track.       Southern    Pacifr 


Figs.  495-498 


BLOCK  SIGNALS. 


ig.  495.     Circuits  for  Normal  Clear  Automatic  Signals  on  Single  Track,  to  be  Used  Instead  of  Those  Shown  in 
Fig.  494,   Where  Section   is   Too   Long  to  be  Included  in  One  Track  Circuit.     Southern  Pacific. 


Operated 

bu  Home 

Arm 


Fig.   496.     Arrangement    of    Circuits   for   Normal    Clear  System;   Distant  Signals   Controlled  by  Polarized  Track 

Circuit.     The  Union  Switch  &  Signal  Company. 


Fig.   497.     Circuits   for    Normal   Clear   System,   Polarized  Track    Circuits    Controlling    Distant    Signals   on    Separ- 
ate  Posts.     The  Union   Switch  &  Signal  Company. 


t»-p 


& 


-  — 


LJ 


Fig.  498.     Circuits   for  Normal   Clear  System  with   Overlap,   No    Distant    Signals;   Polarized   Track   Circuit   Con- 
trolling   Home    Signals.      The   Union    Switch    &    Signal   Company. 


6o 


BLOCK  SIGNALS. 


Figs.  499-501 


NORMAL    CLEAR— POLARIZED    "WIRELESS"    CONTROL. 

Figs.  496-497-498  show  how  the  polarity  of  a  track  circuit  is 
used  by  the  Union  Switch  &  Signal  Co.  in  the  control  of 
signals. 

In  Fig.  496  the  home  and  distant  signals  are  on  the  same 
post.  The  home  signal  is  controlled  directly  by  contacts  on 
the  neutral  armature  of  the  track  relay.  The  distant  signal 
circuit  Is  passed  through  this  contact  on  the  neutral  armature 
and  also  through  the  one  on  the  polarized  armature.  The  dis- 
tant signal  Is,  therefore,  put  in  the  caution  position,  either  by 
a  shunting  of  the  track  circuit  or  by  the  home  signal  in  advance, 
which  reverses  the  polarity  of  the  track  circuit  by  means  of  the 
pole  changer ;  it  is  also  put  to  caution  whenever  the  home  signal 
on  the  same  post  goes  to  stop,  by  means  of  a  circuit  controller 
operated  by  the  home  arm. 

The  presence  of  a  train  in  the  section  de-energizes  the  track 
relay  and  both  arms  assume  the  horizontal  position.'  This  is 
also  done  by  the  opening  of  a  switch  as  shown  near  the  right  of 
the  figure,  the  track  circuit  being  shunted  through  the  contacts 
in  the  switch  box. 

At  the  signal  on  the  extreme  left  of  Fig.  496  all  parts  of  the 
apparatus  are  in  their  normal  position.  The  relay  is  energized 
with  current  of  the  right  polarity  to  close  its  polarized  contact, 
and  the  circuits  for  both  arms  are  closed,  holding  them  clear. 
At  the  second  signal  from  the  left  the  relay  Is  energized,  but 
with  current  of  the  wrong  polarity  to  close  the  polarized  con- 
tact. The  circuit  for  the  home  arm  is  closed  (by  the  neutral 
contact),  but  the  circuit  for  the  distant  arm  is  broken  at  the 
polarized  contact  which  is  open.  At  the  third  signal  from  the 
left  the  relay  is  de-energized,  being  shunted  by  the  switch  box, 
mentioned  above.  This  opens  the  circuit  for  both  arms  at  the 
relay ;  the  distant  circuit  is  again  broken  by  the  circuit  con- 
troller on  the  home  arm.  The  pole  changer,  also  operated  by 
the  home  arm  and  controlling  the  current  from  the  track  bat- 


together  in  the  other  two.     When  the  track  circuit  is  reversed 
the  coils  formerly  neutralized  are  energized  and  vice  versa. 

Only  three  of  the  coils  are  shown  in  the  diagram.     The  relay 
marked  3  is  the  ordinary  track  relay.    The  armature  controlling 


Fig.  499.     Circuit  Diagram  for   Polarized  Cut   Section, 

Effecting  the   Change   in   Polarity  by  the   Use 

of   Two    Separate   Batteries.     Delaware, 

Lackawanna  &  Western. 

the  distant   arm   is   centrally   pivoted   between  the  four  double 
wound  coils. 

Fig.  499  shows  a  wiring  diagram  for  a  relay  box  at  a  polar- 
ized cut  section.  The  relay  shown  Is  the  Union  Switch  &  Signal 
Co.'s  "Universal"  type.  Reversal  of  polarity  in  the  second  sec- 
tion Is  accomplished  by  means  of  a  third  cell  of  battery  con- 
nected in  opposition  to  the  normal  cells,  as  shown  in  the  small 


Fig.    500.      Arrangement  of   Circuits  for  Normal   Clear  "Wireless"     System, 

Polarity  of  Track  Circuits. 


Distant     Signals       Controlled     by 


tery,  Is  here  reversed,  which  results  in  the  caution  position  of 
the  distant  arm  at  the  next  signal  in  the  rear.  At  the  signal 
on  the  extreme  right  the  apparatus  is  normal. 

If  the  switch  should  be  closed  the  relay  at  the  next  signal  in 
the  rear  (now  open)  would  be  energized,  closing  both  contacts. 
The  home  arm  clears  at  once  and  when  clear  completes  the  cir- 
cuit for  the  distant  arm  on  the  same  post ;  it  also  operates  the 
pole  changer.  The  pole  changer  is  arranged  to  "snap"  over, 
so  as  to  allow  the  relay  (at  the  second  signal  from  the  left) 
to  be  de-energized  for  only  an  instant  when  the  change  in  polar- 
ity takes  place.  This  closes  the  polarized  contact,  completing 
the  circuit  that  clears  the  distant  arm.  By  using  the  mechan- 
ism shown  in  Fig.  538  these  circuits  may  be  used  for  a  three- 
position  signal.  The  use  of  the  back  contacts  on  the  relays  is 
explained  in  connection  with  Fig.  534. 

Fig.  497  is  a  circuit  diagram  for  home  and  distant  signals 
with  polarized  track  circuits,  where  the  distant  signal  Is  not  on 
the  same  post  with  a  home  signal.  The  distant  signal  is  con- 
trolled by  the  track  circuit  immediately  in  advance  through  a 
neutral  contact  of  the  relay,  and  by  its  home  signal  through 
the  pole  changer.  The  home  signal  is  controlled  by  both  of 
the  track  circuits  as  one  is  relayed  by  the  other  at  the  distant 
signal. 

Fig.  500  shows  a  "wireless"  track  circuit  arrangement  for 
automatic  block  signals. 

The  distant  signal  is  controlled  by  a  change  of  polarity  in 
the  track  circuit  acting  on  a  special  differential  relay  with  six 
coils.  Four  of  these  are  double  wound,  and  the  other  two  act 
as  an  ordinary  track  relay.  The  local  signal  battery  acts  on 
one  set  of  windings  and  current  from  the  track  circuit  on  the 
other,  In  such  a  way  that  when  the  track  circuit  is  normal  the 
two  circuits  neutralize  each  other  in  two  c.  the  coils  and  act 


diagram.  A  cell  of  the  alkaline  open-circuit  type  is  usually 
employed,  as  it  is  active  only  for  very  short  periods  of  time  in 
comparison  with  an  ordinary  track  battery. 

Normal    clear    three-position    automatic^  signals    on    the    Rock 


Ing.    501.      Circuits    for   Normal    Clear,   Three-Position 
Signals,  Batteries  Feeding  "With  Traffic,"  Home 
Signals  Controlled  Through  Line  Wires  and     . 
Distant  Signals  by  Polarity  of  Line  Cir- 
cuits.    Rock    Island    Lines. 


Figs.  502-503 


BLOCK  SIGNALS. 


61 


Island  system  are  controlled  by  polarized  line  circuits  (Fig. 
501).  Track  batteries  are  placed  at  the  entering  end  of  the 
sections.  The  local  circuit  for  the  first  or  caution  position  is 
controlled  by  the  neutral  points  of  a  500-ohm  polarized  line 
re'ay.  This  line  relay  is  controlled  by  a  circuit  from  battery  at 
signal  in  advance,  through  a,  pole  changer  operated  by  the 
second  position  of  the  advance  signal,  pcint^  of  the  track  re- 
lay for  the  home  section,  over  the  line,  to  and  through  the 
500-ohm  relay  to  common.  The  third  or  clear  position  of  the 
signal  is  controlled  by  the  polarized  points  of  this  relay. 
With  this  system  of  wiring  the  positive  side  of  one  battery  and 
the  negative  side  of  another  may  both  be  connected  to  com- 
mon. Track  circuits  are  not  relayed,  but  when  it  is  necessary 
to  cut  a  section  the  circuit  for  the  500-ohm  relay  is  carried 
through  the  points  of  the  cut  section  relay.  Switch  indicators 
arc  controlled  by  circuit  breakers  on  the  signal  arms  and  by 
the  contacts  on  the  track  relays. 


NORMAL    DANGER LINE     CONTROL. 

Fig.  502  is  a  diagram  of  circuits  for  a  "normal  danger"  sys- 
tem designed  by  the  Hall  Signal  Co.,  using  a  differential  relay 
for  clearing  purposes. 

Consider  a  train  to  be  entering  the  first  block  (at  hoine  signal 
1).  Current  passes  from  the  battery  at  home  signal  5,  over 
line  wire  3,  through  a  normally  closed  contact  in  the  switch 
box,  to  and  through  the  upper  front  contact  of  the  track  relay 


signal  3,  circuit  controller  C,  front  contact  on  differential 
relay  (now  closed)  distant  clutch,  to  common.  This  clears  sig- 
nal 5  in  the  same  manner  as  already  explained  for  signal  3, 
but  when  the  1,000-ohm  relay  (at  signal  5)  is  shunted  the 
differential  relay  will  not  at  once  pick  up,  because  of  the  resist- 
ance of  the  clutch  D  (for  signal  5D),  which  is  in  series  with 
the  eight-ohm  winding.  However,  enough  current  Is  now  flow- 
ing to  energize  this  clutch  and  clear  the  distant  arm  5  D. 

When  the  train  passes  signal  3,  the  track  relay  at  that  point 
is  de-energized,  opening  the  circuits  through  both  the  home  and 
distant  clutches  at  that  point,  and  thus  putting  both  arms  in 
the  horizontal  position.  The  back  contact  on  the  track  relay 
now  connects  wire  5  D  direct  to  common,  permitting  enough 
current  to  flow  through  the  eight-ohm  winding  of  the  differen- 
tial relay  at  signal  5  to  pick  up  its  armature,  as  already  de- 
scribed in  connection  with  the  differential  relay  at  signal  3. 
This  serves  to  clear  the  next  signal  In  advance  of  5  (not 
shown),  which  in  turn  permits  distant  signal  7  D  to  be  cleared 
as  already  described  for  5  D. 

The  switch  indicator  is  controlled  by  the  contact  E,  operated 
by  home  signal  3,  and  also  by  a  front  contact  on  the  track 
relay  at  that  signal.  It  will  be  noted  that  the  use  of  the  1,000- 
ohm  relay  and  shunt  circuit  (through  the  100-ohm  resistance) 
permits  the  same  line  wire  to  be  used  for  controlling  the  dis- 
tant signal  that  is  used  for  clearing  the  home  signal  in  advance 
of  a  train. 


Fig.  502.     Signal  Control  Circuits,  Normal  Danger  Double    Track    Differential    System.     Hall    Signal   Company. 


Man-re  t  etstBnf  cAjfc/i  SO  Ohms  *ach 

I  327 


U4 H-n 

Qaw  1 


Fig.  503.     Signal  Control  Circuits,  Normal  Danger  Double    Track   Differential   System.     Hall    Signal    Company. 


at  home  signal  3,  the  home  clutch,  the  coll  of  the  1,000-ohm 
relay,  the  eight-ohm  coil  of  the  differential  relay,  a  back  contact 
on  the  same  relay,  line  wire  3  D,  back  contact  of  the  track 
relay  at  signal  1  (now  de-energized)  to  common.  This  ener- 
gizes the  1,000-ohm  relay,  closing  its  front  contact  and  thus 
providing  a  shunt  circuit  through  the  100-ohm  resistance  at 
signal  3  to  common ;  enough  current,  however,  continues  to  flow 
through  the  original  circuit  to  keep  the  1,000-ohm  relay  closed. 
The  home  clutch  at  signal  3  is  now  energized,  causing  that  arm 
to  clear  (for  local  signal  circuit  see  Fig.  522).  Circuit  con- 
trollers C  and  D  are  closed  when  signal  3  reaches  the  clear 
position.  D  shunts  the  coil  of  the  1,000-ohm  relay,  de-energiz- 
ing it  and  reducing  the  resistance  in  the  circuit  through  the 
eight-ohm  coil  of  the  differential  relay,  which  allows  enough 
current  to  pass  through  it  to  pick  up  its  armature,  opening  the 
back  contact  which  now  cuts  in  the  150-ohm  winding.  The 
upper  contact  on  the  differential  relay  also  closes  and  completes 
a  circuit  as  follows :.  From  battery  at  home  signal  5,  through 
upper  front  contact  on  track  relay,  home  clutch,  1,000-ohm  re- 
lay and  eight-ohm  coil  and  back  contact  of  differential  relay  at 
Signal  5,  line  wire  5  D,  second  front  contact  on  track  relay  at 


In  Fig.  503,  a  two-ohm  relay  is  substituted  for  the  8-150 
differential,  and  a  500-ohm  relay  In  place  of  the  1,000 ;  other- 
wise the  circuits  are  the  same  and  also  the  sequence  of 
operation. 

Fig.  504  shows  circuits  for  a  normal  danger  system  using 
clearing  relays  operated  by  the  track  circuits.  These  clearing 
relays  are  compound  wound,  having  two  sets  of  coils  each  of 
16  ohms  resistance,  so  connected  to  the  armature  contacts  that 
when  the  relay  is  energized  one  winding  is  cut  out,  and  when 
de-energized  both  windings  are  connected  in  multiple. 

Consider  a  train  to  be  entering  the  first  block  at  signal  1 ; 
the  compound  relay  at  signal  2  is  de-energized  and  its  lower 
back  contact  completes  a  circuit  as  follows :  From  battery  at 
signal  3,  through  line  wire  (home  2),  normally  closed  contact 
in  switch  box,  upper  front  contact  on  the  four-ohm  track  relay 
at  signal  2,  home  clutch,  back  contact  (now  closed)  on  the 
compound  relay,  75-ohm  resistance  to  common.  This  clears  the 
home  arm  at  signal  2,  closing  the  two  circuit  controllers, 
shown  near  the  home  clutch  magnet,  and  completing  a  circuit 
as  follows :  From  the  battery  at  signal  3,  through  the  upper 
front  contact  of  the  four-ohm  relay,  home  clutch  H,  coll  of 


62 


BLOCK    SIGNALS. 


Figs.  504-506 


relay  S,  second  front  contact  on  the  four-ohm  relay,  line  wire 
(dis.  2),  top  back  contact  on  the  compound  relay  at  signal  2, 
distant  clutch  D,  circuit  controller  (now  closed),  to  common. 
Relay  S  at  signal  3  is  now  energized,  closing  a  shunt  circuit 
through  the  75-ohm  resistance  to  common;  this  leaves  enough 
current  passing  through  the  coil  of  this  relay  to  keep  its  arma- 
ture from  releasing.  The  home  clutch  at  signal  3  is  now  ener- 
gized and  its  arm  clears,  closing  the  two  circuit  controllers  and 
shunting  out  the  coil  of  relay  S,  whose  armature  now  drops. 
With  this  coil  shunted  out  enough  current  flows  through  the 
distant  clutch  at  signal  2  to  energize  it  and  clear  the  distant 
arm  at  that  point. 

When  the  train  passes  signal  2,  the  four-ohm  relay  at  that 
point  is  de-energized,  putting  both  arms  in  the  horizontal  posi- 
tion, but  closing  the  line  wire  (dis.  2)  to  common  through  the 
75-ohm  resistance,  by  its  back  contact.  This  holds  the  home 


reliable  circuit  controllers  to  the  disk  mechanism.  It  also 
closes,  through  a  back  contact,  a  path  for  current  through  one 
winding  of  the  compound  relay  to  insure  its  operation  in  case 
the  back  contact  on  the  relay  itself  should  not  make  good 
connection. 

On  the  Baltimore  &  Ohio  there  is  an  installation  of  normal 
danger  automatic  signals  using  a  normally  clcsed  circuit  for 
clearing  signals  in  advance  of  a  train.  A  distinguishing  feature 
of  this  installation  is  the  use  of  electric  lights  in  the  signals, 
which  burn  only  when  a  train  is  approaching.  Typical  circuits 
for  this  installation  are  shown  in  Fig.  506. 

Fig.  507  shows  a  normal  danger  system  for  single  track  in  a 
tunnel.  Signal  1  controls  from  B  to  B.  Signal  2  from  D  to  A. 
Signal  1  clears  through  back  point  of  relay  F  ;  signal  2  through 
back  point  of  relay  I.  Circuit  for  signal  1  is  from  battery  P 
through  front  contact  2  of  relay  I,  front  contact  '2  of  relay  H, 


if  C*/k  <>/•  fofash  ixrffivy 3  -  4OO  Of,™ 


Fig.  504.     Arrangement  of  Circuits  for  Normal  Danger  Double  Track,  with   Clearing  Relay. 


Fig.   505.     Circuits   for   Normal   Danger   Double   Track,  Using  Enclosed  Disk   Signal. 


Fig.   506.     Circuits  for   Normal    Danger   Three-Position  Signals,  with  Electric  Lights  Burning  Only  on  Approach 

of   Train.     Baltimore   &   Ohio. 


signal  at  3  clear,  in  case  the  compound  relay  at  that  point 
should  not  be  de-energized  at  once  when  the  train  enters  its 
circuit.  When  the  compound  relay  at  3  drops,  the  noxt  home 
signal  in  advance  (not  shown)  clears,  as  already  explained  for 
signal  3,  and  permits  the  distant  arm  3  to  clear.  The  switch 
indicator  is  controlled  in  the  same  manner  as  in  Figs.  502-503. 
Fig.  505  shows  an  arrangement  of  circuits  for  the  enclosed 
disk  signal  similar  to  that  shown  in  Fig.  504  for  the  semaphore, 
the  principal  difference  being  the  substitution  of  a  two-ohm 
relay  for  the  circuit  controllers  attached  to  the  home  signal. 
This  relay  is  used  on  account  of  inconvenience  in  attaching 


wire  through  tunnel,  signal  1,  front  contact  1  of  relay  G,  back 
contact  1  of  relay  F,  to  common,  and  back  to  battery.  The 
circuit  for  signal  2  is  exactly  similar.  The  wire  passing  through 
the  tunnel  is  of  small  size,  so  as  to  be  easily  broken  by  the 
patrolman  in  case  of  emergency,  thereby  holding  both  signals 
at  the  stop  position. 

Figs.  508-509  show  a  single  track  normal  danger  system  with 
two  indicators  at  each  switch,  one  for  each  direction.  Signals 
are  cleared  through  back  points  of  the  track  relay  in  the  sec- 
tion in  its  rear  and  the  control  is'  overlapped  in  the  usual  man/ 
ner.  Control  circuits  are  also  broken  through  circuit  break/ 


Figs.  507-510 


BLOCK    SIGNALS. 


on  first  overlap  opposing  signal  in  most  cases,  so  that  should 
CUM'  of  the  signals  stand  clear,  the  opposing  overlap  signal 
could  not  be  cleared.  Separate  signals  are  provided  for  exit 
from  the  siding.  Indicators  in  each  direction  are  controlled 
in  parallel  with  signal  governing  the  block  in  which  they  occur, 


but  in  opposite  direction;  "16-16"  relays  are  used  in  some  cases 
to  avoid  extending  clearing  wire  to  the  other  end  of  the  track 
section.  Home  signals  having  a  distant  are  controlled  through 
a  compound  line  relay.  A  train  approaching  the  distant  signal 
closes  the  back  contact  of  the  track  relay  in  the  section  In  the 


^ 3OOO-0- ^250d-Cfr 


TL/KMEL 
A 


5OOO-O- 


1 


/rrgr  //rs-otsgr/7  Tisrme/. 


Commorr—jj. 


.   507.     Arrangement  of  Circuits  for  Normal   Danger  Signals  on   Single  Track  for  Tunnel  Protection.     New 

York  Central  &  Hudson  River. 


Fig.    508.     Circuits    for    Normal    Danger    Automatic    Signals   on    Single    Track,    with    Double    Switch    Indicators. 

Hall  Signal  Company. 


Fig.    509.     Circuits    for    Normal    Danger    Automatic    Signals    on    Single    Track,   with    Double    Switch    Indicators. 

ff 


ig.  510.    Circuits  for  Normal   Danger  Automatic   Signals  on  Single  Track,  with  Two  Indicators  at  Each  Switch. 


BLOCK  SIGNALS. 


Figs.  511-516 


rear  (in  this  case  a  16-16-ohm  clearing  relay),  thereby  com- 
pleting a  circuit  from  common  through  the  distant  clutch  to 
Hne,  front  contact  of  repeating  relay  governed  by  track  relays 
in  advance,  200-ohm  winding  of  compound  relay,  front  contact 
of  track  relays  in  advance  of  home  signal,  through  line  facing 
switch  box  and  circuit  controller  on  opposing  signal  to  battery 
at  end  of  overlap  section.  This  permits  sufficient  current  to 
flow  to  energize  the  compound  relay,  closing  the  circuit  from 
common  through  to  front  contact,  home  clutch  to  the  home 
control  wire.  This  clears  the  home  signal  and  closes  the  cir- 
cuit breaker  so  that  the  20  and  200-ohm  windings  of  the  com- 
pound relay  are  in  parallel,  thus  reducing  the  resistance  of  the 
circuit  sufficiently  to  permit  the  distant  signal  to  clear. 

Fig.  510  shows  the  same  circuits  as  Figs.  508-509,  except  that 
there  is  but  one  turnout. 


ABSOLUTE-PERMISSIVE    BLOCK     SYSTEM. 

The  General  Railway  Signal  Co.  has  developed  a  system  of 
block  signaling  which  is  termed  the  "Absolute-Permissive"  block 
system — "absolute"  because  it  prevents  trains  from  entering  a 


may  be  changed  to  A.  However,  signal  4  will  not  clear  for  a 
train  running  in  the  direction  of  arrow  S.  Signal  4  in  the 
45  deg.  position  indicates  that  there  is  no  opposing  train  nearer 
than  the  clearing  point  for  signal  9,  but  that  there  is  a  train 
running  in  the  direction  of  arrow  R  between  signals  6  and  8. 
Signal  4  in  the  90  deg.  position  indicates  the  same,  except  that 
there  is  no  train  between  signals  6  and  8,  but  there  may  be  a 
train  running  in  the  direction  of  arrow  R  ahead  of  signal  8. 
In  other  words,  as  soon  as  a  train  reaches  the  clearing  section 
for  signal  9  running  in  the  direction  of  arrow  S  and  signal  9 
clears,  signals  4,  6  and  8  are  held  in  the  stop  position.  The 
"head-on"  protection  is  complete  and  at  the  same  time  following 
trains  are  allowed  to  close  in  to  the  same  extent  as  in  double- 
track  signaling,  getting  the  same  signal  indications. 

If  it  is  desired  that  the  starting  signals  give  a  stop  and  pro- 
ceed as  well  as  a  stop  and  stay  indication,  a  second  arm  can  be 
used  as  shown  in  dotted  lines  in  Fig.  511.  If  this  arm  is  used 
on  signal  4,  for  instance,  it  will  give  the  45  deg.  indication  for 
an  approaching  train  while  the  block  between  C  and  D  Is 


Fig.  511.      .Absolute    Permissive    Block    Signaling    System.      General    Railway    Signal    Company. 


piece  of  single  track  occupied  by  a  train  moving  in  the  opposite 
direction,  and  "permissive"  because  it  permits  one  or  more  trains 
to  enter  a  piece  of  single  track  already  occupied  by  a  train  mov- 
ing in  the  same  direction.  In  Fig.  511  starting  signals  1,  4,  9 
and  12  are  shown  in  the  stop  position.  These  may,  however, 
stand  normally  in  the  clear  position.  If,  for  instance,  signal  4 
Is  a  normal  stop  signal,  its  usual  clearing  point  would  be  at  B. 
If  the  distance  between  B  and  C  is  too  short  the  clearing  point 


occupied  by  a  train  running  in  the  direction  of  arrow  R,  but 
not  when  this  train  is  running  in  the  direction  of  arrow  S. 
Signal  4  is  thus  made  to  give  four  indications,  viz.,  stop  and 
stay,  stop  and  proceed,  proceed  with  caution  and  proceed  at 
speed.  As  many  intermediate  signals  may  be  provided  as  is 
desired.  Each  intermediate  signal  is  a  unit  by  Itself  and  such 
intermediate  signals  may  be  located  in  pairs  opposite  each  other 
or  staggered  as  local  conditions  require. 


HALL    DISC     SIGNALS. 


The  outward  appearance  of  a  Hall  disk  signal  is  shown  in 
Fig.  512.  The  case  is  made  with  wooden  front  and  back  and 
sheet  iron  sides  and  top,  and  is  supported  on  a  post  of  suit- 
able height,  or  on  a  bridge,  and  usually  is  painted  a  dark  color. 
The  disk,  about  18  inches  in  diameter,  made  of  silk  or  other 
light  fabric,  stretched  on  a  metal  ring,  or  of  aluminum,  very 
thin,  is  fixed  to  the  armature  of  an  electro-magnet  in  the  man- 
ner shown  in  Figs.  513-514-515-516.  When  the  signal  magnet 
is  energized  the  armature  holds  the  disk  up,  in  the  position 
shown  at  the  left  of  Fig.  513  ;  and  an  approaching  engineman, 
looking  at  the  glass-covered  opening,  sees  the  back  of  the  inte- 
rior of  the  case,  which  is  of  ground  glass,  white;  this  is  the 
clear  signal.  On  the  withdrawal  of  the  electric  current  the 
disk  drops  by  gravity  to  a  position  before  the  window  (the 


MECHANISMS 

armature  and  rod  turning  on  the  axis  as  shown),  thus  display- 
ing a  red,  or  stop,  signal. 

The  enclosed  disk  is  usually  mounted  on  the  top  of  a  post  or 
pillar,  as  before  stated.  When  home  and  distant  signals  are 
used,  the  cases  are  arranged  as  shown  in  Fig.  512.  The  upper 
signal  has  a  red  disk,  and  is  the  home  signal,  while  the  lower 


Fig.  512.     Disk  Signals  on  the  Philadelphia  &  Reading 
Hall    Signal    Company. 


Figs.    513-516.     Hall    Disk    Mechanisms. 

one  has  a  green  or  yellow  disk,  and  is  the  distant  signal  fov 
Ihi'    block    section    next    beyond.     Fig.    515    illustrates    the    Hall 
disk   mechanism    with    "hold    clear"    attachment.      This   consists  < 
of  an  additional   set  of   magnets   of  high   resistance,    as  shown. 
The   Z  rotary  armature  carries  on  an  arm  a  second  flat  arma- 
ture for  the  "hold  clear"  coils.     A  circuit  breaker  controls  the- 
circuits  for  the  two  sets  of  coils  so  that  when  the  signal  is  ati 
stop   they   are   in   parallel ;    when   at   clear   they   are   in   series. 
Thus   the   signal   is   held  clear  on  a   low  current   consumption. 
Fig.    516   shows  the   Hall   disk' instrument  used  by   the  Chicago! 
&    North-Western.      This    has    two    separate    night    indications. 
The  magnet  has  only  one  coil  instead  of  two. 


Figs.  5J7-520 


BLOCK    SIGNALS. 


UNION    DISK    SIGNALS. 

The  Union  Switch  &  Signal  Co.'s  disk  signal  is  shown 
in  Figs.  517-518.  In  this  design  the  case  is  of  metal  (pressed 
steel).  It  is  made  very  narrow,  leaving  room  enough  only 
for  the  disk,  and  the  electro-magnet  is  contained  in  a  box 


rig.  517.     Enclosed  Disk  Signal.     Union  Switch  & 
Signal    Company. 


Fig.   518.     Enclosed    Disk    Signal;   Two-Colored    Night 
Indication. 


outside  the  main  case.  The  joints  of  the  case  are  calked, 
making  it  airtight,  so  that  the  disk  cannot  be  affected  by 
moisture.  The  box  containing  the  magnet  is  also  tight,  but 
can  be  unlocked  by  the  repairman.  The  front  and  rear 
glasses  are  of  heavy  plate  fixed  in  brass  rings.  The  lamp 


Fig.  520. 


Disk  Mechanism  for  Showing  Two-Colored 
Night   Indications. 


is  supported  on  hinges,  so  that  it  can  be  turned  around  to  be 
cleaned  and  filled.  The  whole  case  and  the  parts  supported 
by  it  are  very  light,  important  parts  being  made  of  aluminum, 
and  it  may  be  revolved  on  its  bearings. 

In  the  Union  Switch  &  Signal  Co.'s  style  of  signal 
(Fig.  517)  the  night  signal  is  a  lamp  fixed  at  the  back  of  the 
disk,  outside  the  case,  showing  uncolored  for  clear  and  illu- 
minating the  glass  set  into  the  disk  for  the  opposite  indication. 
In  the  Hall  signal  the  lamp  is  placed  behind  the  smaller 
opening  near  the  top  of  the  case,  and  the  upper  end  of  the 
rod  which  carries  the  main  disk  has  fixed  to  it  a  small  trans- 
parent disk,  colored  to  correspond  to  the  color  of  the  day 
disk. 

Fig.  520  shows  how  the  Union  disk  signal  may  be  made  to 
give  two  distinct  night  indications.  The  glass  set  into  the 
disk  is  the  stop  or  caution  color  ;  the  one  projecting  from  the 
disk  is  the  clear  color. 

The  metal  disk  shown  above  is  in  the  same  position  that  It 
would  be  if  it  were  mounted  inside  the  case  and  indicating  stop  ; 
the  upper  glass,  which  is  red,  being  opposite  the  lamp.  The  lamp 
is  supported  at  the  back  of  the  case,  and  its  location  is  indicated 
in  Fig.  518  by  the  small  white  glass  disk  in  the  upper 
part  of  the  large  opening.  To  change  the  indication  of  the 
signal  from  stop  to  proceed  the  metal  disk  is  moved  upward  and 
the  glass  (green),  which  is  attached  to  its  lower  part,  then 
comes  opposite  to  the  lamp.  In  the  daytime  the  proceed  indica- 
tion of  this  signal  is  shown  by  the  contrast  between  the  color 
of  the  outside  of  the  case  and  that  of  the  back  side  of  the  inter- 
ior, as  is  done  in  the  older  designs  of  enclosed  disk  signals. 


Fig.   519.     Disk  Mechanism  for  Enclosed  Disk  Signal. 
Union    Switch    &    Signal    Company. 


HALL,    STYLE    "F." 

Figs.  523-524  illustrate  the  Hall  Signal  Company's  style  "F" 
two-arm  motor  signal  mechanism.  In  the  illustrations  the 
left  half  of  the  mechanism  is  shown  in  the  clear  position  and 
the  right  half  in  the  stop  position.  One-arm  mechanisms  are 
exactly  like  two-arm  mechanisms,  except  that  one  set  of  clutch 
magnets,  one  thrust  rod,  thrust  piece,  clutch  lever,  etc.,  are 
omitted.  The  cast-iron  base  supports  the  motor,  clutch  coils, 
pistons  of  the  dash-pot  and  the  frame  14.  This  frame  sup- 
ports the  clutch  lever  15.  The  steel  thrust  rod  22  is  rigidly 
pinned  to  the  cylinder  of  the  dashpot  6.  The  base  has  two 
pedestals  rigidly  attached  to  support  the  pistons  for  the  dash- 
pots.  The  piston,  in  conjunction  with  the  cylinder,  forms  the 
guide  for  the  lower  end  of  thrust  rod  22.  The  upper  end  of 
this  rod  runs  in  a  babbitted  bearing  in  the  frame.  Secured 
to  the  thrust  rod  is  the  latch  support  33,  which  carries  the 
clearing  lever  35,  the  thrust  piece  28  and  the  latch  which 
engages  the  lug  on  the  clutch  lever  15  to  hold  the  signal  clear. 
The  thrust  piece  carries  the  latch  31,  which  engages  the  lug 
on  clearing  lever  35.  The  large  gear  wheels  are  phosphor 
bronze.  They  are  driven  by  the  steel  pinion  3  on  the  motor 
and  the  pinion  and  shaft  4.  The  phosphor  bronze  knife  blade 
contacts  of  the  circuit  controller  19,  Figs.  523-524,  are 
operated  by  the  circuit  controlling  rod  9  attached  to  the  escape- 
ment crank  11.  The  escapement  crank  is  controlled  by  the 
roller  attached  to  the  latch  support  33.  The  front  armature 
of  the  clutch  magnets  controls  the  multiple  contacts  for  the 
motor  circuit.  The  back  armature  is  attached  to  the  clutch 
lever  15,  which  enables  the  magnets  to  control  the  clutch 
lover.  20  is  a  multiple  circuit  controller  which  Is  operated 
in  the  same  manner  as  19.  Glass  cases  37  cover  the 
armature  and  contacts  of  the  clutch  magnets  17  and  18  to 


66 


BLOCK    SIGNALS. 


Figs.  521-524 


exclude  dust.  12  performs  the  same  function  as  11,  but  is 
left-handed.  10  corresponds  in  the  same  way  to  9.  33  slides 
in  guides  in  the  frame.  25  is  a  part  of  the  main  frame  which 
carries  the  bearings  for  the  two  gear  wheels,  2  and  5.  In 
Figs.  525-526  is  shown  the  guide  30  for  the  carriage  29  which 
carries  33.  The  motor  1  (see  Figs.  525-526)  is  series  wound. 
The  fields  are  laminated  iron  with  but  one  joint,  which  is 
dovetailed,  making  them  further  continuous  and  reducing  the 
magnetic  loss  on  account  of  joints  to  a  minimum.  The 


When  the  home  signal  is  at  stop  the  circuit  controller  con- 
tacts for  the  motor  are  closed  and  the  contacts  controlling  the 
distant  clutch  magnets  are  opened  so  that  it  is  impossible 
for  the  distant  signal  to  clear  until  after  the  home  signal 
has  cleared.  When  the  home  signal  clutch  magnet  is  energized 
it  closes  the  motor  circuit  to  the  contacts  on  the  front  arma- 
ture 17  and  at  the  same  time  holds  the  back  armature  32, 
which  prevents  the  clutch  lever  from  moving  when  pressure 
is  applied  to  clear  the  signal.  The  home  circuit  being  closed^ 


C/rcis/f  Cor/fro//er 
0/7  Sign  a/  Arm 


C/ufc/7  Magrnet  \ 
Armature  — 


-  D'?.tg'r7t  C/ear/ny  _ 

Home  C/ecrrinar 
^ 


Fig.  521.     Local  Wiring  for  Single  Arm  Style  "F" 
Electric  Motor  Signal  Mechanism. 


Fig.    522.      Local   Wiring   for   Two-Arm   Style  "F' 
Electric  Motor  Signal  Mechanism. 


armature  and  commutator   are   completely   enclosed  by   a  brass  the    motor    revolves    the   gears    and    brings    the   stud    roller    24 

case  over  the  armature  and  a  glass  case  over  the  commutator.  under  the  thrust  piece  28  and  pushes  it  up.     Since  the  clutch 

The  glass  case  is  held  in  position   by  two  springs  bearing  on  lever  15  is  held  by  this  armature,  it  prevents  the  clearing  lever 

two    lugs  '  on    the    glass.      The    shaft    runs    in    self-oiling    ball  35  from  swinging  back  and  by  means  of  the  lug  on  this  lever 

oearings.  engaging  the  latch  31  in  the  thrust  piece  28,  carries  the  thrust 


Numbers  refer  to  lists  of  names  of  parts  on 
following  page. 


13 


22 


14 


37- 


Figs.  523-524.     Style  "F"  Electric  Motor  Signal        Mechanism.       Hall     Signal     Company. 


Figs.  525-526 


BLOCK    SIGNALS. 


67 


rod  and  all  the  parts  attached  to  the  clear  position.  In  moving 
to  the  clear  position  the  roller  pivoted  on  the  lower  end  of 
clearing  lever  35  rolls  along  the  front  edge  of  clutch  lever  15. 
In  the  last  one-eighth  inch  movement  of  the  signal  to  the 
clear  position  the  roller  attached  to  the  latch  support  33 
strikes  the  front  lever  of  the  escapement  crank  11  and  moves 


stop  by  gravity.  The  movement  of  the  signal  to  stop  is 
cushioned  by  the  dashpot  6.  The  circuit  controllers  are 
reversed  as  soon  as  the  signal  begins  to  go  to  the  stop  posi- 
tion. If  by  any  chance  the  motor  circuit  should  be  closed 
without  the  clutch  magnets  being  energized,  the  motor  would 
simply  revolve  the  gears,  and  when  the  stud  roller  engaged 


i-23 


13 


Figs.  525-526.     Style  "F"  Electric  Motor  Signal  Mechanism,  Equipped  for  Three-Position  Signal. 

Hall  Signal  Company. 

Names  of  Parts  of  Hall  Electric  Motor  Signals;  Figs.  523,  524,  525,  526. 
Two-Arm  and  Three-Position. 


1  Motor 

2  Gear  Wheel 

3  Motor  Pinion 

4  Shaft  Pinion 

,  5  Driving  Gear 

6  Dash  Pot 

7  Rocking  Beam 

8  Rocking    Beam    Operating    Rods 

9  Circuit  Closer  Rod  R.  H. 

10  Circuit  Closer  Rod  L.  H. 

11  Escapement  Crank  R.  H. 

12  Escapement  Crank  L.  H. 

13  Clutch  Lever  Shaft  Bearing 


14  Frame 

15  Clutch  Lever  R.  H. 

16  Clutch  Lever  L.  H. 

17  Clutch  Magnets  R.  PI. 

18  Clutch  Magnets  L.  H. 

19  Circuit  Closer  R.  H, 

20  Circuit  Closer  L.  H. 

21  Screiv  Jazv 

22  Thrust  Rod 

23  Thrust  Rod  Cover 

24  Lifting  Roller 

25  Side  Frame  R.  H. 

26  Side  Frame  L.  H. 


28  Thrust  Piece  L.  H. 

29  Thrust  Piece  Carriage 

30  Carriage  Guide 

31  Latch 

3ia  Hold  Clear  Latch 

32  Clutch  Armature 

33  Latch  Support 

34  Safety  Latch 

35  R.  H.   Clearing  Lever 

36  L.  H.  Clearing  Lever 

37  Glass  Contact  Cover 


it  on  its  pivot,  and  by  means  of  the  rod  24  operates  the  circuit 
controller.  This  opens  the  motor  circuit  and  closes  a  contact 
in  the  distant  signal  circuit.  The  signal  is  held  in  the  clear 
position  by  the  lug  on  the  clutch  lever  15,  engaging  under  a 
latch  on  latch  support  33.  This  leaves  the  gears  free  to 
continue  their  movement,  as  soon  as  the  distant  clutch  magnet 
is  energized  to  clear  the  distant  signal.  After  the  signal  has 
been  cleared  the  stud  roller  24  moves  from  under  the  thrust 
piece  28.  When  the  signal  circuit  is  broken  the  clutch  mag- 
net Is  de-energized.  The  front  armature  opens  the  motor 
contacts  to  keep  the  motor  circuit  open  and  the  back  armature 
being  released  permits  the  clutch  lever  15  to  swing  back  far 
enough  for  the  holding  latch  in  the  latch  support  33  to  pass 
the  lug  on  the  clutch  lever  and  allow  the  signal  to  go  to 


the  thrust  piece  it  would  raise  it  without  affecting  the  signal, 
as  the  clearing  lever  35  would  be  free  to  swing  back  and  permit 
the  latch  31  to  pass  it.  When  the  stud  roller  passed  from 
under  the  thrust  piece  it  would  drop  back  in  place  and  be 
ready  to  clear  the  signal  when  the  clutch  magnet  energized. 
Or  If  the  clutch  magnet  should  become  de-energized  when  the 
signal  was  partly  cleared,  the  clearing  lever  35  would  be  per- 
mitted to  swing  back  on  account  of  clutch  armature  being 
released,  and  allow  the  latch  31  to  pass  the  lug  from  the 
clearing  lever,  the  signal  would  go  to  stop,  the  thrust  piece 
28  would  remain  on  top  of  the  stud  roller  by  swinging  on  its 
pivot,  and  when  the  stud  roller  moved  from  under  It,  it  would 
drop  back  in  its  place  ready  for  another  operation  in  which 
the  parts  would  operate  as  described. 


68 


BLOCK    SIGNALS. 


Figs.  527-532 


Names  of  Parts  of  Hall  Pole  Changer.     Figs.  529-530. 

A  Disk  Carrying  Operating  Pin  F  Lugs  on  E 

B  End  Bearing  of  Frame  with  Stop  G  Insulating  Link 

C  Pawl  H  End  Bearing  of  Frame 

D  Lug  on  A  K  Porcelain  Base 

E  Spring  Case  or  Drum  L  Bracket 


M  Binding  Posts 

N  Shaft 

O  Clamp  Arm 

P  Upper   Contact 

R  Lower  Contact 


Figs.    527-528.     Circuit   Controller   for   Automatic    Sig- 
nals.    Hall  Signal  Company. 


Figs.  529-530.     Pole  Changer  for  Automatic  Signals. 


21 


Figs.   531-532.     Electric    Motor  for   Style  "F"    Mechanism. 

Names  of  Parts  of  Electric  Motor  for  Style  "F"  Mechanism;   Figs.  531-532. 
i     Laminated  Field  Cores  8     Bearing   Support,   Back  15    Brush  Holder 


2  Field  Coils 

3  Laminated  Yoke 

4  Base 

5  Glass  Commutator  Shield 

6  Commutator 

7  Bearing  Support,  Front 


9  Pinion 

10  Brake  Wheel 

11  Brake  Adjusting  Screw 

12  Brake  Shoe 

13  Brake  Armature  Screw 

14  Brake  Armature  Spring 


1 6  Brush 

17  Brush  Holder  Support 

18  Brush  Holder  Tension  Spring 

19  Wedge 

20  Armature 

21  Brake  Armature 


Figs.  533-534 


BLOCK    SIGNALS. 


69 


Figs.  521-522  show  circuits  for  wiring  the  mechanism  of  a 
one  and  two-arm  Style  "F"  Hall  motor  signal.  The  full  lines 
represent  wiring  furnished  with  the  mechanism,  the  dotted 
lines  the  wiring  which  must  be  done  after  the  signal  has 
been  installed.  Fig.  522  is  used  when  this  signal  is  in  the 
normal  danger  system  (see  Figs.  502-504)  ;  Fig.  521  may  also 
be  used  when  this  style  of  signal  is  used  as  a  power  operated 
signal  at  an  interlocking  plant. 

Figs.  525-526  show  front  and  side  elevation  of  a  three-posi- 
tion Style  "F"  motor  mechanism.  This  is  identical  in  con- 
struction with  the  mechanism  shown  in  Figs.  523-524,  except 
for  the  addition  of  several  parts.  (Numbering  of  parts  is  the 
same  as  in  Figs.'  523-524.)  Two  guides,  23,  for  the  thrust 
piece,  22,  are  mounted  on  top  of  the  frame.  These  act  also 
as  guides  for  the  jaw,  21,  which  is  attached  to  the  up-and- 
down  rod.  21  carries  the  rocking  beam,  7,  each  end  of  which 
is  attached  to  one  of  the  thrust  rods,  22,  by  means  of  link 
8.  Thus,  raising  one-half  of  the  mechanism  as  shown  puts 
the  signal  to  the  45-deg.  or  caution  position.  Raising  both 
parts  clears  the  signal.  No  glass  covers  are  shown  on  17 
and  18. 

A  view  of  the  Hall  Signal  Co.'s  circuit  controller  (19 
and  20,  Figs.  523-524,  525-526,  15,  Fig.  585)  is  shown  in 
Figs.  527-528.  It  consists  of  a  porcelain  base  to  which  a  bronze 
frame  is  secured.  The  base  also  supports  the  spring  knife 
switches,  the  contacts  and  the  binding  posts.  The  frame  acts 
as  a  bearing  for  a  shaft  and  also  as  a  means  of  attachment 
to  the  mechanism.  The  shaft  carries  one  or  more  clamped 
arms  to  which  are  secured  links  made  of  fiber.  To  the  lower 
end  of  these  links  the  spring  knife  contacts  are  fastened. 

The  pole  changer  made  by  the  Hall  Signal  Co.  is  shown 
in  Figs.  529-530.  K  is  a  porcelain  block.  H  is  the  brass  frame 
carrying  the  shafts,  N,  and  serving  as  a  means  of  attach- 
ment to  the  signal  mechanism.  L  is  a  bronze  support  for  the 
upper  contacts,  P,  and  binding  posts.  All  binding  posts,  M, 
are  similar.  Clamp  arms,  O,  are  fastened  to  the  shaft  and 
carry  insulating  links  G.  These  links  actuate  the  knife  blades, 
S.  Lower  contacts,  K,  are  similar  to  upper  contacts,  P. 
Attached  to  the  shaft,  N,  is  a  drum,  E,  within  which  there 
is  a  spiral  spring,  one  end  fastened  to  the  drum,  the  other 
to  disk  A.  A  moves  loosely  on  N  and  carries  a  pin  to  which 
the  operating  rod  is  fastened.  Suppose  A  to  be  revolved  to 
the  right.  Motion  would  be  imparted  to  E  through  the  spring, 
but  one  of  the  lugs,  F,  would  catch  in  the  notch  of  pawl 
C,  which  is  pivoted  to  the  frame.  This  would  prevent  E  and 
N  from  revolving  so  that  further  motion  of  A  would  compress 
the  spring.  When  A  reaches  a  point  where  lug  D  strikes  pawl 
C  and  raises  it,  the  spring  will  cause  E  and  N  to  snap  over  and 
carry  the  knives  S  to  the  upper  contacts  P.  C  is  prevented 
from  flying  too  far  by  stop  B.  When  A  is  revolved  to  the  left, 
lug  D  strikes  a  second  lug  F  on  E,  and  thereby  moves  knives 
S  to  the  lower  contacts  by  means  of  N  and  G. 


position  shown  at  A,  Fig.  537,  the  lugs  S,  on  the  fork  head  5 
engage  hooks  on  the  pawl  24  (shown  dotted  in  Fig.  537). 
This  supports  the  arm  in  the  clear  position.  In  assuming  this 
position  the  top  of  slot-arm  strikes  against  the  lever  46.  This 
causes  the  insulated  block  39  to  raise  contact  spring  28  off 
of  contact  spring  29,  thereby  opening  the  motor  circuit  and 
stopping  the  motor.  It  also  closes  the  circuit  for  the  distant 


UNION    STYLE    "B." 

The  two-arm  motor  signal  mechanism  made  by  the  Union 
Switch  &  Signal  Company  is  shown  in  Fig.  535.  Fig.  537 
shows  the  same  mechanism  partly  in  section.  The  operation 
of  the  slot-arm  is  shown  in  Figs.  540-542.  When  the  signal 


Fig-  533-     Union  Style  "B"  Electric  Semaphore.     One- 
Arm   Two-Position   Left-Hand  Upper  Quadrant 
Signal    (6o-deg.)    Furnished    for   the    Illinois 
Traction   System   and    Equipped  for 
A.  C.  Operation. 

signal  (Fig.  534).  In  order  that  pawl  24  shall  be  certain 
to  engage  lugs  S,  a  spring,  45,  is  fastened  to  lever  46.  Its 
lower  end  bears  on  pawl  24,  therefore,  the  raising  of  lever  46 
by  the  slot-arm  puts  tension  on  the  spring  and  forces  pawl  24 
into  engagement  with  the  lugs  S.  When  the  slot  magnet  is 
de-energized  the  armature  4  falls  away  by  gravity.  This  re- 


534-     Wirin 


Diagram    for    Style    "B"    Automatic  Signal    When    Operated    by    Direct    Current    and    Con- 
trolled by  Polarized  Relay. 


is  in  the  stop  position  and  current  is  supplied  to  clear  it,  the 
operation  is  as  follows  :  (For  circuit  see  Fig.  534.)  Current 
passes  from  relay  to  home  slot  coil  7  and  motor  M  (see  Fig. 
537)  in  multiple.  The  motor  revolves  the  gear  3  by  means 
of  the  large  gear  1  and  pinion  2.  This  causes  the  trunnion 
12  on  chain  10  to  engage  the  prongs  of  the  fork  head  5,  and 
move  the  slot-arm  about  G  (see  Fig.  540)  as  a  center.  This 
clears  the  signal  which  is  operated  by  an  up  and  down  rod 
attached  at  K  by  jaw  6.  When  the  slot-arm  has  reached  the 


leases  latch  D,  permitting  link  F  and  fork  head  5  to  assume 
the  positions  shown  in  Fig.  542.  This  allows  the  signal  to 
go  to  the  stop  position.  A  dashpot  8  provides  an  air  cushion 
to  absorb  shocks.  Fork  head  spring  35  restores  the  fork  head 
to  its  normal  position  after  the  slot-arm  has  passed  the  trunnion 
or  pawl  when  returning  to  the  stop  position.  One  feature  of 
this  signal  is  the  arrangement  of  parts  whereby  the  slot 
armature  4  moves  both  to  and  away  from  the  pole  pieces  by 
gravity.  The  distant  slot  7'  clears  the  distant  signal  in  ex- 


BLOCK    SIGNALS. 


Figs.  535-536 


actly  the  same  -way  as  the  home  was  cleared,  except  that  it 
has  two  windings,  one  high  and  one  low  (see  Fig.  534).  Con- 
necting link  31  is  used  to  actuate  a  pole-changer  P  or  circuit 
controller  C  for  the  control  of  outside  circuits.  Single  arm 


Fig.  534  shows  the  arrangement  of  local  wiring  when  used 
with  the  polarized  track  circuit,  as  shown  in  Fig.  496. 

The  slow  release  on  the  home  slot  magnet  is  accomplished  by 
means  of  a  copper  sleeve  over  the  core  of  the  magnet  inside 


Fig.  535-     Style  "B"  Electric  Motor  Signal  Mechanism;  Home  Slot  in  Clear  Position;  Distant  Slot  at  Caution. 

Union  Switch  &  Signal  Company.  -^ 


l> 


8pf 

filSA 


To  Transformer 


X    I  ]  To  Transformer 


&rcr/te. 
Fig.    536.     Wiring    Diagram    for    Style    "B"    Automatic  Signal   When    Operated  by  Alternating   Current. 


mechanisms  are  furnished  with  only  one  slot-arm,  sprocket, 
chain,  and  dashpot.  Fig.  539  is  a  view  of  the  gear  and 
sprocket  wheels  with  their  bearings  and  chains.  This  con- 
stitutes the  running  gear  of  the  mechanism. 


the  coil.  This  acts  as  a  short-circuited  winding  of  large 
current  capacity  which  induces'  sufficient  magnetism  in  the 
core  to  keep  it  energized  a  short  time  after  the  current  has 
been  cut  off  from  the  coils  on  account  of  the  current  induced 


Fig.  537 


BLOCK    SIGNALS. 


in  It  when  the  holding  circuit  is  broken.  The  object  of  this 
arrangement  is  to  hold  the  home  arm  clear  while  the  track 
relay  Is  momentarily  de-energized  by  the  reversal  of  the  track 
circuit.  This  slow  acting  feature  is  required  only  in  the 
polarized  system. 

The  back   contact  on  the  neutral   armature   of  the   relay   also 


assists  in  the  slow  release  of  the  home  slot,  by  closing  a  local 
circuit,  without  battery,  through  it  when  the  relay  is  de- 
energized,  thereby  allowing  self-induced  current  to  flow  through 
the  slot  coil. 

The   compound    winding   on    the   distant   slot    magnet   Is    pro 
vided   to   economize   in   the   use   of   current.     The   motor   circuit 


Fig-  537-     Sectional    View,    Style    "B"    Motor    Mechanism.      Union    Switch    &    Signal    Company. 
Names  of  Parts,  Union  Style  "B,"  Motor  Signal  Mechanism;  Fig.  537. 


1  Main  Gear  Wheel 

2  Counter  Sliaft  and  Pinion 

3  Intermediate  Gear  Wheel 

4  Slot  Armature 

5  Forked  Head 

6  Screzv  Jaw 

7  Pair  Home  Slot  Magnets 
71  Pair  Distant  Slot  Magnets 

8  Buffer  Cylinder 

9  Lower  Sprocket  Wheel 

10  Chain 

11  Piston  Rod  for  Buffer  Cylinder 

12  Trunnion 

13  Upper  Sprocket  Shaft 

14  Upper  Sprocket  Wheel 

15  Loiver  Contact  Spring  for  Pole  Changer 

16  Upper  Contact  Spring  for  Pole  Changer 

17  Motor  Brush 

18  Check  Valve  for  Buffer  Cylinder 

19  Lower  Contact  Spring  for  Circuit  Controller 

20  Upper  Contact  Spring  for  Circuit  Controller 
24  Pawl  for  Supporting  Slot- Arm 

28  Long  Contact  Spring 

29  Short  Contact  Spring 

31  Pole  Changer  Operating  Link 


32  Operating  Arm  for  Pole  Changer- 

33  Piston  for  Buffer  Cylinder 

34  Mechanism  Base 

35  Coil  Spring  for  Forked  Head  of  Slot-Arm 

36  Main  Gear  Shield 

37  Slate  Base  for  Contact  Springs 

38  Binding  Post 

39  Insulation  for  No.  46 

40  Buffer  Cylinder  Bracket 

41  Contact  Spring  Board  Bracket 

42  Long  Upright  for  Frame 

43  Short  Upright  for  Frame 

44  Bearing  Bracket 

45  Spring  for  Circuit  Closing  Lever 

46  Circuit  Closing  Lever 
A  Home  Slot-Arm  Casting 
B  Distant  Slot-Arm  Casting 

C  Contact  Piece  for  Circuit  Controller 

D  Latch 

E  Three  Way  Crank 

F  Link  tvith  Stop 

M  Motor 

P  Pole  Changer 

S  Lug  on  5 


BLOCK    SIGNALS. 


Figs.  538-539 


passes  through  the  low  resistance  winding  and  is  opened 
when  the  distant  arm  reaches  the  clear  position  The  slot  then 
holds  the  arm  clear  by  current  in  the  2,000-ohm  coil  only. 

Fig.  536  is  a  wiring  diagram  used  in  place  of  that  shown  in 
Fig.  534  when  the  signal  is  to  be  operated  by  alternating 
current. 

Fig.  538  shows  the  double  arm  mechanism  (Figs.  535-537) 
equipped  to  operate  a  single  arm  three  position  signal.  The  up 
and  down  rod  terminates  in  a  jaw  carrying  a  pinion.  This 
pinion  engages  on  each  side  with  a  rack  operated  by  each 


Fig.  538.     Style  "B"   Mechanism   Equipped  for  Three- 
Position   Signal.     The  Union   Switch    & 
Signal  Company. 

slot-arm.  The  pinion  and  two  racks  are  enclosed  in  a  case 
clamped  to  the  frame  tubing.  Tims,  when  one  slot-arm  is 
raised  its  rack  revolves  the  pinion  which  travels  upward  on 
the  other  rack.  This  puts  the  signal  in  the  intermediate 
position.  Raising  of  the  second  slot-arm  causes  the  pinion 
to  travel  up  the  first  rack  and  completes  the  stroke  of  the 
signal. 

The  direct  current  motor  (Fig.  544)  is  series-wound  and  is 
usually  designed  to  work  on  1 2  volts.  Its  brake  is  controlled 
by  the  field  magnet,  and  its  commutator  is  protected  by  a 
glass  shield,  as  shown. 


-  539-     Running  Gear  and  Shield,  Style  "B"  Motor 
Signal.     The   Union   Switch   &  Signal   Company. 


TXIOX     STYLE     "S." 

The  SI. vie  "S"  signal  is  a  development  of  the  above-described 
Style  "B"  signal  along  lines  adapted  to  meet  the  requirements 
of  three-position  automatic  block  signaling. 

The  signal  has  been  designed  to  work  with  either  direct  or 
alternating  current,  shaded  pole  slot  magnets  and  induction 
motor  being  used  in  the  latter  case. 

In  the  Style  "S"  three-position  signal  but  one  slot  arm  with 
its  transmission  parts  is  employed  for  the  operation  of  each 
semaphore  arm.  An  air  buffer  is  pivoted  to  the  frame  imme- 


Figs.  540-545 


BLOCK    SIGNALS. 


73 


diately  below  the  point  on   the  slot  arm   to  which   the  vertical 
signal  rod  is  attached. 

The  upper  end  of  the  buffer  piston  rod  and  the  lower  end  of 
the  signal  rod  are  fitted  with  jaws  and  connect  to  the  slot  arm 
with  one  common  pin  in  the  same  manner  as  the  well-known 


ers,  are  dispensed  with.  The  controller  is  equipped  throughout 
with  non-turning  binding  posts  and  otherwise  is  designed  to 
comply  with  Railway  Signal  Association  requirements. 

The   circuits   for  the   intermediate   or  45-deg.    position   of  the 
arm   pass  through  this  controller,   which  also  serves  as  a  main 


MACNCTSDl-CNEKC/ZCD 
(ARMATUR1  UNLATCHED.) 


Figs.    540-542.     Sections    Through    Slot    Arm,    Showing 
Successive  Positions,  Style  "B"   Mechanism. 


Fig-  543-     Union  Style  "S"  D.  C.  Motor 
Mechanism. 


Fig.  544.     Electric  Motor  for  Style  "B"  Automatic 
Signal. 

wide  and  narrow  jaws  are  connected  to  a  crank  in  mechanical 
interlocking  practice.  This  method  transmits  the  shock  of  the 
signal  arm  when  returning  to  "stop"  directly  to  the  buffer. 

The  main  circuit  controller,  to  which  a  pole  changer  can  be 
applied  when  required,  is  located  to  the  right  and  above  the 
slot  arm,  thus  providing  space  for  two  relays  in  each  mechanism 
case  and  keeping  the  controller  contacts  out  of  the  way  of  oil 
and  dirt. 

The  base  of  the  controller  is  made  of  porcelain  dipped  in 
black  Insulating  varnish.  By  this  means  all  hidden  insulations 
liable  to  be  charred  by  lightning,  such  as  bushings  and  wash- 


Fig.  545.     Union  Style  "S"  A.  C.  Motor  Mechanism. 


74 


BLOCK    SIGNALS. 


Figs.  546-548 


terminal  board  for  the  mechanism.  Additional  circuit  control- 
lers are  carried  on  the  left-hand  upper  corner  of  the  mechanism 
and  operated  directly  by  the  slot  arm. 

The   slot   arm   is   identical   in   design   and   principle  with   that 


Fig.  546.     Union  Style  "E"  Motor  Mechanism. 

used    on   the   style    "B"    except    that    the   fork   head    or    lifting 
<Tank  is  three-pronged. 

Two  chains  are  employed,  the  center  lines  of  which  are  tan- 
gential to  the  arc  described  by  the  slot  arm.  The  lower  chain 
lifts  the  slot  arm  from  the  "stop"  to  the  "caution"  position, 
and  the  upper  from  the  "caution"  to  the  "clear"  position. 
The  chains  are  staggered  with  relation  to  each  other,  the 


lower  engaging  the  front  and  middle  prongs  of  the  fork  head, 
and  the  upper  the  middle  and  rear  prongs. 

The  slot  arm  rests  on  hooks  in  both  the  caution  and  clear 
positions,  thus  retaining  two  of  the  important  features  of  the 
Style  "1!"  signal.  vi/.  :  I  1  )  The  clear  and  caution  positions  arc 
definite  and  do  not  depend  on  the  adjustment  of  circuit  con- 
trollers; and  (2)  in  both  these  positions  the  signal  is  entirely 
free  from  its  running  gear.  The  mechanism  frames  are  of  cast 
iron,  secured  to  each  other  by  steel  bolts  and  spacers. 

The  motor  straddles  a  pin  passing  through  both  frames,  to 
which  It  Is  secured  by  set  screws.  A  connection  between  the 
motor  and  a  cam  on  the  frame  permits  of  adjustment  between 
the  motor  pinion  and  the  gears. 

By  a  modification  of  the  slot  arm  leverages  on  both  the  Style 
"S"  and  "B"  mechanisms  the  mechanical  kick-off  or  the  coun- 
terweight effect  tending  to  force  the  slot  armature  away  from 
the  magnet  coils  has  been  increased  175  per  cent  without 
increasing  the  current  consumed  for  holding  the  signal  at  clear 
or  caution. 


UNION     STYLE     "E." 

The  signal  mechanism  illustrated  in  Fig.  546  is  the  Style 
"E"  top  post,  adapted  to  either  lower  or  upper  quadrant  indi- 
cation, for  operation  by  direct  current  at  any  desired  voltage, 
or  by  alternating  current  of  any  frequency  and  voltage. 

In  this  mechanism  the  motor  is  never  operated  in  reverse 
direction,  a  clutch  being  interposed  between  the  semaphore 
shaft  and  the  gearing  by  which  the  motor  operates  the  signal 
in  one  direction.  This  clutch  is  under  the  control  of  an  electro 
magnet,  which,  when  energized,  holds  the  gearing  between  the 
motor  and  semaphore  shaft  continuous  ;  and  when  the  magnet 
is  de-energized  the  continuity  is  interrupted  and  the  signal 
returns  by  gravity,  independently  of  the  motor  and  the  gearing. 

Another  unique  feature  in  connection  with  this  signal  is  in 
the  design  of  buffer,  which  is  composed  of  a  cylinder  and  a 
piston  moving  therein,  which  latter  has  a  complete  reciprocat- 
ing movement  for  each  45  deg.  movement  of  the  signal; — in 
other  words,  a  suction  and  a  compression  stroke.  Because  of 
comparatively  high  speed  of  the  piston  within  the  cylinder  that 
is  obtained  by  this  arrangement,  a  very  loose  fit  of  the  piston 
within  the  cylinder,  without  the  use  of  rings,  is  permissible, 
while  a  highly  effective  buffing  effect  is  obtained. 


UXION     STYLE     "T." 

In  this  mechanism  the  motor  is  geared  to  the  semaphore 
shaft  so  that  its  armature  rotates  with  the  semaphore  shaft  in 
either  direction.  The  ratio  of  gearing  of  the  motor  to  the  shaft 
is  so  low  that  the  effort  of  turning  the  armature  offers  very 
little  resistance  to  the  descent  of  the  counterweight.  Electro- 
motive force  is  applied  to  the  motor  when  the  signal  is  going 


fig.  547.     Union  Style  "E"  Motor  Mechanism. 


Fig.  548.     Union  Style  "T"  Motor  Mechanism. 


Figs.  549-551 


BLOCK    SIGNALS. 


75 


toward  the  danger  position,  so  as  to  assist  the  counterweight. 
Normally  no  current  is  used  in  going  to  danger,  because  the 
counter  electro-motive  force  of  the  motor  driven  by  the  counter- 
weight exceeds  the  electro-motive  force  of  the  battery,  but  if 
anything  should  occur  to  offer  unusual  resistance  to  motion  the 
motor  would  assist  in  putting  the  signal  to  danger. 

The  motor  acts  as  a  brake  after  the  current  is  cut  off  when 
running  in  either  direction.  This  is  useful  when  the  signal  is 
going  to  the  caution  or  clear  position,  as  it  prevents  over- 
running no  matter  how  the  voltage  may  vary  and  when  the 
signal  is  going  to  danger,  as  it  brings  the  arm  to  rest  gently 
on  the  stop. 

The    signal    is '^  adaptable    to    either    high    or    low    voltage, 
direct   current. 


G.     R.     s.     MUDEL     "2A." 

Figs.  549-563  shows  views  of  direct  connected  and  base  of 
mast  Mcdel  2A  mechanism  for  automatic  block  signaling. 
They  are  designed  to  be  operated  by  alternating  current  of 
any  voltage  and  frequency  or  by  low  voltage  direct  current. 


are  connected  by  a  coupling  which  lends  itself  to  a  simple 
means  of  locking  the  semaphore  in  the  normal  position,  this 
preventing  improper  operation  of  the  signal  by  any  outside 
agency.  The  motor  is  directly  connected  to  the  semaphore 
shaft  through  a  train  of  gears  so  that  the  armature  revolves 
with  it  in  either  direction.  By  the  use  of  a  high  torque,  low 
speed  motor,  low  reduction  gearing  is  used,  but  30  revolutions 
of  the  motor  being  required  to  clear  the  signal  to  the  90 
deg.  position. 

The  direct  current  signal  is  held  in  the  desired  proceed 
positions  by  means  of  a  retaining  device  (Fig.  555)  with 
which  the  motor  is  equipped.  It  consists  of  an  electro-magnet, 
the  armature  of  which  is  connected,  through  a  crank  and  link 
movement,  to  a  dog  designed  to  engage  a  toothed  disk  mounted 
on  the  armature  shaft  of  the  motor ;  the  design  embodies  an 
escapement  movement  so  that  when  the  electro-magnet  is 
energized,  the  motor  armature  will  be  held  only  when  It 
begins  its  rotation  toward  the  stop  position.  An  exceedingly 
high  drop  away  is  procured  through  having  an  air  gap  of 
.020  of  an  inch,  this  being  more  than  twice  the  air  gap 
ordinarily  used  in  connection  with  this  type  of  mechanism. 


Fig.  549.    Model  "2-A"  Direct  Connected  Signal  Mechanism.     Low  Voltage,  D.  C.  Control. 
General   Railway  Signal   Company. 


The  mechanisms  will  control  any  aspect,  two  or  three  positions 
of  the  semaphore  blade,  upper  or  lower  quadrant,  right  or 
left  hand  and  through  any  angle  of  movement  desired  up  to 
00  deg. 

The  direct  connected  signal  is  clamped  to  the  mast  by  means 
of  a  clamp  bearing  which  enables  it  to  be  mounted  anywhere 
on  new  or  existing  poles,  or  any  number  on  a  given  pole.  To 
assure  proper  alignment,  the  driving  and  semaphore  shafts 


Due  to  the  motor  being  driven  backwards  when  the  sema 
phore  is  returning  to  the  stop  position,  electrical  means  may 
be  used  for  stopping  the  movement  of  the  signal  blade,  with- 
out the  use  of  a  dash-pot  or  other  additional  mechanical 
contrivance.  This  is  accomplished  in  the  last  few  degrees' 
movement  of  the  mechanism  by  shunting  the  motor,  which 
causes  it  to  generate  sufficient  current  to  effectively  check  the 


Fit-;.  550.     Model  "2-A"  A.  C.  Suspended  Signals.    New 
York,    New    Haven    &    Hartford    Railroad. 


Fig.    551.     Model    "2-A"    D.    C.    Automatic    Signals. 
Northern  Pacific  Railroad. 


76 


BLOCK  SIGNALS. 


Figs.  552-554 


speed   of    the   mechanism    so    that   the   signal    parts   and  sema- 
phore blade  are  brought  to  stop  without  shock. 
The   motor    used   for   a.    c.    operation    may   be   either   of   the 


stator  winding  and  its  laminated  iron  core,  the  latter  being 
mounted  on  the  armature  shaft  of  the  motor.  When  the 
mechanism  is  assuming  the  proceed  position,  the  core,  through 


40" 


90°RELAr  CONTROL 
COMMON 

Fig-  552-     Wiring  Diagram  for  Model  "2- A"  Automatic  Signal.     Low  Voltage  D.  C.  Control. 


OPENS 

•i* 

1 

T~^ 

i  — 

±^ 

-£ 

I 

—  46° 

E 

88° 
-9f 

.-0                  + 

< 

i- 

—  43                J 

—  88             ~i 

• 

• 

• 

P-  •-»*_*                   — 

• 

• 

rftAi 

.42— 

["CLOSED  ONLY    ON 
[BACKWARD    MOVT. 


4-0° 


-46" 
91° 


MOTOR 

90°  CONTROL  — 
COMMON 


N/WWWWV 


HIGH    VOLTA6E    TRANSMISSION     LING 


Fig.  553-     Wiring  Diagram  for  Model  "2- A"  Automatic    Signal,  A.  C.  Control. 


Fig.    554-     Universal    Model    "2- A"    Direct    Connected    Signal    Mechanism.     General    Railway   Signal    Company. 


commutating  or  induction  type,  both  of  these  motors  having 
such  efficiency  that  they  may  operate  directly  over  the  line 
without  the  intervention  of  line  relays.  The  a.  c.  signals 
are  held  in  the  different  proceed  positions  by  means  of  a 


the  medium  of  a  simple  and  efficient  clutch,  remains  stationary 
when  its  stator  winding  is  energized;  the  moment  reverse 
movement  starts  to  take  place,  the  clutch  clamps  this  core 
to  the  armature  shaft  and  holds  the  signal  blade  in  the 


Figs.  555-559 


BLOCK    SIGNALS. 


77 


Fig.    555.     Retaining    Mechanism.     Model    "2-A* 
Low  Voltage  D.  C.  Signal. 


position  to  which  It  has  been  moved.  The  operation  of  holding 
the  blade  clear  is  not  dependent  on  mechanical  contact  in 
any  way,  but  is  due  entirely  to  torque  produced  by  lines  of 
flux  flowing  between  pole  surfaces  separated  by  a  large  air 
gap ;  when  the  retaining  current  is  cut  off,  the  torque  existing 
between  the  core  and  stator  pole  pieces  ceases  to  exist  and  the 
blade  returns  to  the  stop  or  next  lower  position,  as  the  case 
may  be.  Figs.  556-557  are  views  of  complete  and  partial  as- 
semblies of  the  retaining  device. 

In  the  base  of  mast  signal  the  same  motor,  gearing  and  cir- 
cuit breaker  parts  are  used  as  In  the  direct  connected  type. 
The  frame  is  designed  to  carry  one  or  two  mechanisms,  which 
will  operate  one  or  two  arms  respectively,  controlling  any 
aspect,  two  or  three  positions,  etc.  Space  is  available  at  the 
top  of  the  case  for  control  and  track  relays,  and  at  the  side 
for  lightning  arresters  and  fuse  and  terminal  boards. 

The  wiring  for  the  a.  c.  and  d.  c.  mechanisms  and  circuits 
for  their  control  are  shown  in  Figs.  552-553. 


Fig.  556.     Rotor  of  Hold  Clear  Reactance  Model  "2-A"      Fig.  557.     Hold  Clear  Reactance.     Model  "2-A"  A.  C. 


A.   C.  Signal. 


Signal. 


D-LOW    VOLTAGE   MOTOR  COHK 


Figs.  558-559.    Motor  for  Universal  Model  "2-A"  Signal.     Low  Voltage  D.  C.  Control.     General  Railway  Signal 

Company. 


BLOCK    SIGNALS. 


Figs.  560-563 


Fig.    560.      Universal    Model    "2- A"    Base-of-Mast    Signal 
Mechanism.     A.  C.  Control. 


Fig.  561.     Model   "2- A."   A.   C.   Bracket   Signals.      Lc 
Island  Railroad. 


Fig.  562.     Model  "2- A"   Base-of-Mast   Signal  Mechanism.       Fig.    563.    Model  "2- A"  D.  C.  Automatic  Block  Signal. 
Low  Voltage  D.  C.  Control.  Northern    Pacific   Railroad. 


Figs.  564-566 


BLOCK    SIGNALS. 


79 


HALL  STYLE  "It." 

Figs.  564-566  illustrate  the  Style  "II"  top  post  electric 
semaphore  signal  made  by  The  Hall  Signal  Co. 

The  operating  mechanism,  a  general  view  or  which  Is  shown 
in  Fig.  566,  is  composed  of  the  motor  and  its  gears,  a  clutch 


Fig.  564.     Style  "H"   Signal  in   Case.     Hall  Signal 
Company. 


magnet  of  the  disc  type  with  its  armature,  and  the  circuit 
controller.  The  holding  mechanism,  shown  in  Fig.  565,  is  com- 
posed of  a  piston  and  cylinder  with  oil  reservoir  and  valves, 
and  the  holding  magnets. 

The  clutch  magnet  "a"  (Fig.  570)  is  keyed  to  the  semaphore 
shaft  by  key  "b"  and  the  armature  "c"  is  held  In  position 
by  pins  "d"  In  the  clutch  magnet,  so  that  the  armature  re- 
volves with  the  magnet,  but  is  free  to  move  laterally.  A 
Norway  iron  clutch  ring  "e"  is  fitted  Into  the  large  gear  "f" 
and  Is  placed  between  the  clutch  magnet  and  its  armature. 
This  clutch  ring  revolves  with  the  gear,  independent  of  the 
clutch  magnet  and  armature,  and,  like  the  clutch  armature, 
is  allowed  a  slight  lateral  motion.  When  the  power  is  applied 
to  the  motor,  the  large  gear  "f,"  which  is  connected  to  the 
motor  pinion  by  a  chain  of  gears,  revolves  and  carries  with 


Fig-   565.     Complete   Holding   Mechanism  of   Style 
"H"   Signal. 


Fig.    566.     Style    "H"   Mechanism.      Hall    Signal 
Company. 

it  the  clutch  ring.  The  circuit  through  the  clutch  magnet 
is  in  multiple  with  the  motor  circuit,  and  is  closed  when  the 
motor  circuit  Is  completed.  Since  the  clutch  ring  is  between 
the  clutch  magnet  and  its  armature,  it  is  clasped  rigidly  be- 
tween them  by  the  force  of  attraction,  and  the  clutch  magnet 
and  semaphore  shaft,  to  which  it  is  attached,  are  forced  to 
revolve  with  the  clutch  ring  and  large  gear,  thus  clearing 
the  semaphore  blade.  When  the  blade  reaches  the  45-deg. 
position,  the  circuit  for  the  motor  and  clutch  is  opened  through 
the  circuit  controller  operated  by  the  clutch  magnet,  and  the 
blade  Is  free  to  come  to  rest  or  return  to  the  stop  position. 
If  the  contact  on  the  distant  relay  is  closed,  however,  the 
circuit  for  the  motor  and  clutch  is  again  completed  by  a 


8o 


BLOCK    SIGNALS. 


Figs.  567-570 


multiple  circuit,  and  the  blade  is  moved  to  the  clear  position, 
when  this  circuit  is  again  opened  by  another  contact  on  the 
circuit  controller.  Fig.  567  shows  the  circuit  which  controls 
the  operating  functions  of  the  mechanism.  All  the  movements 
of  the  blade  from  the  danger  position  are  accomplished  in 


cylinder  "j."  The  cylinder  is  connected  to  the  oil  reservoir 
"k"  by  the  port  "1,"  this  port  being  controlled  by  valves  "m" 
and  "n."  Valve  "m"  is  connected  to  the  armature  of  the  hold- 
ing magnets  by  stem  "r,"  and  when  these  magnets  are  energized, 
the  valve  "m"  Is  closed.  Valve  "n"  is  automatic  In  action; 
with  valve  "m"  closed,  and  with  a  weight  on  the  piston 
tending  to  force  the  liquid  from  the  cylinder  to  the  reservoir, 


<?/  4S° 


£>/s/  ///?<? 

Fig.  567.     Operating  Circuit  of  Style  "H" 
Mechanism. 


Fig.    568.     Operating    and    Holding    Clear    Circuit    of 
Style    "H"    Mechanism. 


Fig.  570.     Details 

of  Gears  and 

Clutch  Ring  of 

Style    "H" 

Signal. 


Fig.    569.     Details    of   Oil    Cylinder    of    Hold-Clear 

Mechanism. 

the  manner  described,  and  no  apparatus  other  than  the  motor, 
gears,  circuit  controller  and  clutch  magnet  are  required  for 
this  function. 

The  blade  Is  held  in  its  position  of  rest  by  the  holding 
mechanism  in  the  following  manner :  The  piston  "g"  (see 
Fig.  569)  connected  to  the  clutch  magnet  by  rod  "h"  moves  in 


valve  "n"  Is  closed  by  the  pressure  of  liquid  against  it,  and  both 
passages  from  the  cylinder  to  the  reservoir  are  closed.  When 
the  piston  is  carried  vertically  by  the  movement  of  the  clutch 
magnet,  the  liquid  in  the  reservoir  is  drawn  into  the  cylinder 
by  suction  through  valve  "n."  When  the  signal  blade  comes 
to  rest  in  its  position  of  caution  or  clear,  If  the  holding 


Figs.  571-574 


BLOCK    SIGNALS. 


81 


magnets  are  energized  and  valve  "m"  accordingly  closed,  the 
weight  of  the  signal  on  the  piston  tends  to  force  the  oil  back 
into  the  reservoir,  but  in  doing  so  automatically  closes  valve 
"n"  and  the  piston  is  held  in  its  position  of  rest.  A  further 
movement  of  the  piston  repeats  this  operation.  The  signal 
Is  accordingly  held  clear  by  the  oil  in  the  cylinder. 

When  the  holding  magnet  is  de-energized  by  the  opening  of 
the  circuit,  valve  "m"  is  opened,  and  the  opening  of  this  valve 


Fig.   571.     Installation  of  Style  "H"  Automatic   Signal 
Mechanism.     Hall  Signal  Company. 

provides  a  free  passage  for  the  oil  from  the  cylinder  to  the 
reservoir.  The  size  of  the  opening  of  valve  "m"  is  adjusted 
so  that  the  return  flow  of  oil  is  regulated  in  such  a  manner 
as  to  permit  the  blade  to  return  to  its  normal  position  with 
sufficient  retardation  to  prevent  jarring  the  mechanism.  The 
circuit  of  the  complete  operating  and  holding  mechanism  is 
shown  in  Fig.  568. 


AMERICAN    TOP    POST    MECHANISE!. 

Fig.  573  shows  the  top-post  signal  made  by  the  American 
Railway  Signal  Co.  This  mechanism  operates  without  a  dash- 
pot  and  without  any  mechanical  latch.  The  revolving  wheel 
carrying  the  fan  blades  acts  as  a  dashpot,  while  the  rim  of  the 
wheel  is  the  armature  for  the  slot  coils,  holding  the  blade  in 
Us  positions  by  means  of  tractive  force  only.  No  adjustment 


Fig.  572.     Top  Post  Signal  Motor.     American  Railway 
Signal   Company. 

is  to  be  made  between  the  rim  of  the  wheel  and  the  slot  mag- 
net. The  cores  of  the  slot  coils  extend  over  the  rim  of  the  large 
wheel  and  are  provided  with  rings  considerably  larger  than, 
and  free  to  run  on,  the  cores.  These,  through  magnetic  at- 
traction, grip  the  armature,  holding  the  blade  in  the  proper 
signal  position.  When  -the  current  is  cut  off  the  slot  coils, 
the  rings  are  de-energized,  allowing  the  wheel  to  revolve  by 
the  weight  of  the  blade,  and  the  fan,  acting  as  a  dashpot, 


Fig.  573.     Top   Post  Signal  Mechanism,   Cover  Down. 
American  Railway  Signal  Company. 


Fig.  574.     Top  Post  Signal.     American  Railway  Signal 
Company. 


82 


BLOCK    SIGNALS. 


Figs.   575-577 


not  only  prevents  the  jar  to  the  blade  when  it  roaches  the 
horizontal  position,  but  also  drives  out  the  accumulated  dead 
air  from  the  case,  keeping  the  mechanism  dry  and  free  from 
moisture.  This  signal  will  operate  in  two  or  three  positions 
and  in  the  upper  or  lower  quadrant.  The  case  is  water-tight 
and  admits  of  all  parts  being  exposed  to  view.  Condensation 
is  reduced  to  the  practicable  minimum. 


AMERICAN    BASE-OF-MAST    MECHANISM. 

Figs.  575-576  illustrate  the  two-arm  electric  motor  mechan- 
ism made  by  the  American  Railway  Signal  Co.  The 
distinguishing  feature  of  this  mechanism  is  the  use  of  a  re- 
volving fan  instead  of  a  dash-pot  for  preventing  shocks  when 
the  signal  moves  by  gravity  to  the  stop  position.  This  fan 
also  causes  a  circulation  of  air  in  the  case,  tending  to  pre- 
vent the  accumulation  of  frost  and  ice  on  the  moving  parts. 
While  the  motor  is  engaged,  the  fan  remains  idle,  adding 
nothing  to  the  work  of  the  motor.  The  same  mechanism  can 
be  used  to  operate  a  one-arm  signal  for  either  two  or  three 
positions ;  or  a  two-arm  signal  for  either  two  or  three  posi- 
tions, the  arms  to  be  moved  separately  or  both  at  the  same 


and  it  acts  through  vertical  rods,  which  may  be  seen  at  each 
side  (Pigs.  575-579)  projecting  through  the  base  plate. 
The  object  of  the  clutch  is  to  cut  the  motor  clear  of  the 
mechanism  as  soon  as  the  arm  has  been  brought  to  the  clear 
position.  The  mechanism  operates  the  arm  by  means  of  a 
quarter  inch  phosphor  bronze  rod  of  2,100  Ibs.  tensile  strength. 
The  signal  is  held  clear  by  means  of  clutch  magnets,  seen  at 
the  top  of  the  illustrations.  These  magnets  are  protected 
from  moisture  or  dirt  dropping  from  above  by  bell-shaped 
shields.  When  the  signal  goes  to  the  stop  position  it  causes 
the  whole  mechanism,  except  the  motor,  to  revolve  back- 
wards ;  and  the  weight  and  friction  of  the  parts  suitably 


Fig.    577-      Mechanical 

Semaphore    Lock 

on  Base-of-Mast  Signal 

Mechanism. 


Figs.   575-5/6.     Mechanism   for   American   Railway   Signal  Company's  Semaphore  Signal. 


time,  and  the  arms  may  be  moved  in  either  the  upper  or  the 
lower  quadrant.  The  arm  may  be  stopped  at  any  angle  and 
immediately  returned  to  the  position  giving  the  desired  sig- 
nal indication  without  first  going  to  the  stop  position.  The 
circuit  controller  is  enclosed  in  a  water-tight  case.  With  this 
mechanism  the  signal  is  pulled  to  the  clear  position  so  .that 
the  vertical  rod  need  not  be  so  heavy  and  stiff  as  where  the 
signal  is  cleared  by  pushing  the  rod  upward.  The  motor  Is 
enclosed  in  a  dust-proof  case,  with  a  glass  covering  over  the 
commutator.  The  clutch  which  causes  the  motor  to  engage 
with  the  gears  is  operated  by  a  magnet  which  is  in  series 
with  the  motor.  This  clutch  is  enclosed  in  a  water-tight  iron 
case  bolted  to  the  underside  of  the  plate  supporting  the  motor, 


modified  by  the  fan  serve  to  provide  the  necessary  cushioning 
to  prevent  any  shock  when  the  signal  arm  comes  to  its  normal 
position. 

Fig.  577  illustrates  the  connection  of  the  operating  rod  or 
chain  to  the  semaphore  shaft,  the  signal  and  arm  being  now  in 
the  stop  position.  The  chain  lies  in  a  groove  in  the  sheave. 
Having  been  slackened,  to  permit  the  arm  to  assume  this 
position,  it  has  been  forced  in  toward  the  shaft  so  that  it  does 
not  hang  in  a  straight  line.  It  is  kept  in  this  position  by  the 
flat  spring  attached  to  the  lock  dog,  and  the  lug  on  the  lock 
dog  prevents  the  shaft  from  .being  turned.  When  power  is 
applied  to  the  chain  it  is  pulled  taut,  and  this  throws  the 
dog  clear  of  the  sheave. 


Figs.  578-579 


BLOCK    SIGNALS. 


Figs.   5/8-579.     American    Railway   Signal    Company's    Base-of-Mast    Electric    Semaphore    Signal    Mechanism. 


FEDERAL    MECHANISM. 

The  signal  mechanism  made  by  the  Federal  Signal  Co. 
is  arranged  to  operate  either  one  or  two  arms.  It  is  com- 
posed of  the  two  upright  stands  1  and  1'  (Fig.  580)  which,  are 
securely  bolted  to  base  2.  These  frames  are  connected  at 
the  top  by  the  buffer  base  casting  on  which  are  mounted  the 
buffer  cylinders  4  and  4'.  Two  main  shafts  or  spindles  5 
and  5'  turn  in  bearings  6  and  6'  formed  in  the  frames  1  and 
1',  additional  bearings  7  and  7'  are  formed  in  the  bracket  8 
which  is  bolted  to  the  frame  1  and  1'  and  acts  also  as  a  tie 
for  the  frames.  The  shafts  5  and  5'  turn  in  bearings  7  and  T. 
On  the  outside  of  the  frames  1  and  1',  mounted  on  the  shafts 
5  and  5',  are  the  main  driving  gear  wheels  9  and  9'.  A  shaft 
or  spindle  10  is  mounted  in  bracket  bearings  11  and  11',  which 
are  secured  to  frames  1  and  1',  respectively.  Upon  this  shaft 
10  is  secured  the  worm  wheel  12  which  meshes  with  and  is 
driven  by  the  worm  13  on  the  shaft  14  of  the  motor  15.  Bracket 
support  17  carries  a  thrust  bearing  16  for  the  worm  13.  The 
flexible  connection  18  in  the  motor  shaft  14  is  employed  to 
relieve  the  motor  from  any  friction  due  to  the  thrust  of  the 
worm  13.  On  the  .shaft  10  are  loosely  mounted  the  pinions 
19  and  19'  which  mesh  with  the  gear  wheels  9  and  9'  re- 
spectively. A  clutch  sleeve  20  is  also  fixed  to  the  shaft  10 
and  turns  with  it,  but  is  also  arranged  to  slide  from  side  to 


side.  This  is  accomplished  by  a  slotted  hole  in  the  sleeve  20 
and  a  pin  in  the  shaft  10.  On  the  extreme  ends  of  the  sleeve 
20  are  cut  notches  or  teeth  21  and  21'  which  engage  with 
similar  teeth  22  and  22'  of  the  pinions  19  and  19'.  A  grooved 
collar  23  is  formed  in  the  sleeve  20  and  is  operated  by  the 
lever  24,  which  is  riveted  at  25  on  the  frame  1.  On  the 
spindles  5  and  5'  between  the  bearings  6  and  7  and  6'  and  7' 
are  secured  the  operating  cranks  26  and  26'.  To  one  end  of 
each  of  these  cranks  are  connected  jaws,  as  shown  at  27,  to 
which  are  attached  the  up  and  down  rods  28.  The  opposite 
ends  of  the  cranks  26  and  26'  are  connected  by  the  rod  29 
to  the  buffer  piston  30.  On  the  lower  edge  of  the  crank  26  is 
bolted  a  lug  49,  in  the  curved  face  50  of  which  is  cut  a  cam 
groove  51.  This  groove,  when  rotated,  forces  the  end  52  of 
the  lever  24  from  right  to  left.  This  operates  the  clutch 
sleeve  20  from  left  to  right,  thus  disengaging  it  from  the 
pinion  19  and  engaging  it  with  the  pinion  19'.  The  caps  31 
and  31'  of  the  buffer  cylinders  4  and  4'  are  fitted  with  ad- 
justable air  vents  32,  and  the  pistons  30  and  30'  are  fitted 
with  ball  valves  33,  which  open  and  allow  the  air  to  enter 
the  cylinders  4  and  4'  during  the  downward  stroke  of  the 
pistons  and  close  to  prevent  the  air  from  escaping  back 
through  the  pistons  during  their  upward  stroke. 

Outside    the   main    gears    9    and    9'    on    the   shafts    5    and   5' 


84 


BLOCK    SIGNALS. 


Figs.  580-582 


Fig.  583 


BLOCK  SIGNALS. 


are  secured  the  magnet  supports  34  and  34'  on  which  are 
bolted  magnets  35  and  35',  supporting  armatures  as  shown 
at  60.  Armature  levers  36  and  36'  are  pivoted  to  lugs  37 
and  37'  of  the  support  34  and  34'.  The  short  ends  38  and 
38'  of  the  levers  36  and  36'  connect  by  pins  39  and  39'  with 
the  long  ends  of  the  links  40  and  40'  which  are  pivoted  on 
pins  as  shown  at  41.  The  short  ends  of  the  links  40  and 
40'  project  outward  toward  the  periphery  of  the  main  gears 
9  and  9'  in  the  path  of  the  roller  studs  42.  These  studs  are 
situated  on  the  sides  of  the  gears,  and  as  many  as  are  re- 
quired may  be  used.  A  counterweight  pawl  43  is  attached 
to  the  frame  1  by  pivot  stud  44.  The  tooth  45  of  the  pawl 
rests  at  certain  times  between  the  teeth  of  the  gear  wheel 
to  prevent  the  wheel  9  from  revolving  backward.  Another 
tooth  46  is  also  fixed  to  the  side  of  pawl  43  ;  this  tooth  is 
somewhat  longer  than  the  tooth  45  and  normally  rests  in 
one  of  the  notches  46  which  are  formed  in  the  edge  of  the 
rim  of  the  gear  9.  This  edge  48  is  formed  by  reducing  the 
face  of  the  gear  9  to  a  depth  even  with  the  bottom  of  the 
teeth  of  the  gear.  Circuit  controlling  devices  53  and  53'  of 
a  quick  break  type  are  fastened  to  the  base  2  and  are  con- 
nected to  and  operated  by  the  cranks  26  and  26'  through  the 
rods  54  and  54'. 

If  the  top  or  home  arm  is  to  be  cleared  the  coils  of  magnet 
35  are  energized  by  closing  a  circuit  from  a  source  of  energy. 
The  magnet  will  hold  the  armature  60  against  its  poles  and 
thus  maintain  the  lever  36  and  the  link  40  rigidly  in  the 
position  shown.  If  current  be  now  applied  to  the  motor  15 
its  armature  will  revolve  and  through  the  medium  of  its 
shaft  14  and  clutch  18  will  cause  worm  13  to  revolve,  which 
will,  in  turn,  rotate  worm  wheel  12  and  shaft  10.  Shaft  10 
in  turning  will  revolve  the  pinion  19  through  the  medium 
of  the  sleeve  20,  the  left-hand  teeth  of  which  engage  with 
the  teeth  of  the  pinion  19.  The  pinion  19  meshing  with  the 
main  gear  9  which  is  loosely  mounted  on  the  shaft  5  will  now 
revolve,  and  one  of  the  studs  42  which  are  mounted  thereon 
will  strike  against  the  projecting  end  of  the  link  40.  In  so 
doing  the  magnet  arm  34,  which  is  rigidly  attached  to  shaft  5, 
will  be  partially  revolved,  turning  shaft  5  with  it  and  also 
crank  26,  which  is  also  rigidly  attached  to  the  shaft.  Crank 
26  in  swinging  will  lift  the  up  and  down  rod  28  sufficiently 
to  move  the  signal  blade  the  required  distance.  At  this  point 
the  circuit  controller  53,  which  is  actuated  by  the  crank  26, 
will  cut  off  the  current  from  the  motor  15,  but  not  from 
the  magnet  35.  The  crank  26  will  also  actuate  the  shifting 
lever  24  and  throw  the  clutch  sleeve  over  from  left  to  right, 
disengaging  pinion  19  and  engaging  pinion  19'. 

While  gear  9  has  been  revolving  the  tooth  46  of  the  pawl  43 
has  been  resting  against  the  surface  48  of  the  gear  9,  thus 
holding  the  tooth  45  out  of  engagement  with  the  teeth  of 
gear  9.  At  the  same  instant,  however,  that  the  clutch  sleeve 
20  is  released  from  pinion  19,  the  notch  47  in  the  edge  48  of 
the  gear  9  arrives  at  a  point  adjacent  to  the  tooth  46  of  the 
pawl,  thus  allowing  the  pawl  to  swing  and  its  tooth  45  to 
engage  with  the  teeth  of  gear  9,  arresting  any  backward 
movement  of  the  gear.  The  signal  arm  thus  cleared  will  remain 
so  as  long  as  magnet  35  remains  energized.  If  the  lower  or 
distant  arm  is  to  be  cleared  the  motor  15  is  again  energized 
by  a  circuit  through  the  distant  controller  53'  and  magnet  35'. 
The  clutch  sleeve  20  being  now  in  engagement  with  the  pinion 
19'  will  cause  the  pinion  to  revolve,  transmitting  its  rotary 
motion  to  the  main  gear  9',  clearing  the  distant  signal  in  the 
same  manner  as  the  home  signal  was  cleared. 

Upon  the  de-energization  of  the  magnets  35  or  35'  the  re- 
spective signals  will,  on  account  of  their  counterweight,  return 
to  stop  without  turning  backward  either  of  the  gears  9  or  9'. 
This  is  accomplished  as  follows :  When  the  armature  60  is 
released,  the  weight  resting  on  the  lever  26  will  cause  the 
lever  36  and  link  40  to  hinge  or  toggle  at  point  39,  this 
toggling  will  withdraw  the  projecting  end  of  link  40  from  its 
point  of  contact  with  the  roller  stud  42  and  allow  the  crank 
26  to  come  to  rest.  This  returning  movement  is  retarded  by 
the  buffers  4  or  4'.  The  distant  signal  in  going  back  to  normal 
position  does  not  in  any  way  affect  the  clutch  sleeve  20, 
which  still  remains  in  connection  with  pinion  19'.  Therefore, 
if  the  distant  section  of  track  governed  by  this  signal  be 
occupied  and  vacated  the  signal  will  automatically  return 
to  its  normal  position  and  then  clear  again  without  affecting 
the  home  mechanism.  If,  however,  the  home  section  should 
be  occupied  the  home  signal  would  return  to  stop  position, 
and  in  so  doing  would  throw  back  the  clutch  sleeve  from  pinion 
19'  to  pinion  19,  thus  rendering  it  impossible  to  clear  the 
distant  signal  again  until  the  home  section  was  vacated  and 
the  home  signal  cleared.  This  apparatus  can  be  made,  if  de- 
sired, to  operate  a  single  signal  by  leaving  off  the  right-hand 
portion  of  the  mechanism. 


THE     ELECTRO-GAS     MECHANISM. 

Figs.  583-586  illustrate  the  two-arm  electro-gas  signal  mech- 
anism made  by  the  Hall  Signal  Co.  Single  arm  mechanisms 
are  similar  to  these,  except  that  they  have  only  half  as  many 
moving  parts.  In  Fig.  585  one-half  of  the  mechanism  is  shown 
in  the  position  for  a  clear  indication  and  the  other  half  for 
the  stop  indication.  The  controlling  power  of  this  signal  is 
electricity,  the  operating  power  liquefied  carbonic  acid  gas. 
The  gas,  stored  in  an  iron  cylinder  (Fig.  587)  at  the  foot  of 
the  signal  post,  is  normally  at  a  pressure  of  from  600  to 
1,200  Ibs.  per  sq.  in.,  and  for  use  is  reduced  through  a  reg- 
ulating valve  (Fig.  588)  to  from  40  to  60  Ibs.  pressure  per 
sq.  in.  Pipe  27,  Fig.  585,  leads  to  the  mechanism  from  the 
main  receptacle.  The  signal  rod  which  operates  the  sema- 
phore arm  is  connected  to  the  clamp  31,  attached  to  the 
cylinder  rod,  and  the  gas  when  admitted  to  the  cylinder  1 
causes  the  cylinder  and  its  rod  to  move  upward  and  the  arm 
to  assume  the  clear  position.  The  cylinder  is  movable  and 
its  piston  is  fixed.  The  flow  of  gas  into  the  cylinder  and  its 
egress  therefrom  are  controlled  through  valves  9-10,  Fig.  58  f 
(shown  enlarged  in  Fig.  589),  which  in  turn  are  controlled 


Fig.   583.     Reducing  Valve  for  Electro-Gas  Signal. 
Hall  Signal  Company. 

by  the  electro-magnets  16.  The  lever  or  clutch  which  holds 
the  signal  clear  is  controlled  by  a  back  armature  on  these 
magnets.  When  the  magnets  are  energized  the  front  armature 
17  is  attracted.  This  armature  is  attached  to  a  pivoted  crank, 
to  one  arm  of  which  a  connecting  rod  16  is  fastened.  The 
valves  which  control  the  flow  of  gas  into  the  cylinder  and  its 
escape  therefrom  are  controlled  by  this  connecting  rod  so  that 
when  the  armature  is  attracted  the  supply  valve  is  opened 
and  the  exhaust  valve  closed,  which  makes  a  free  path  for  the 
gas  from  the  tank  to  the  cylinder.  This  path  from  the  gage 
and  regulator  5-6  is  through  the  expansion  chamber  and  its 
connection  29,  through  the  valve  9,  which  has  been  opened  by 
the  movement  of  the  armature,  through  tube  30  to  the  inside 
of  the  cylinder  1.  The  pressure  causes  the  cylinder  to  move 
upward  on  its  piston  and  clear  the  signal.  Clutch  casting  23 
is  clamped  to  the  cylinder  rod  and  moves  with  it  along  the 
guide  32.  Roller  stud  25,  screwed  into  the  clutch  casting  23, 
moves  along  cut-off  lever  8  until  it  raises  pawl  22,  which  is 
pivoted  on  a  stud  screwed  into  the  frame  21.  Cut-off  lever  8 
is  shaped  like  an  inverted  T  and  is  pivoted  on  its  left  leg 
at  the  bottom.  The  right  leg  is  connected  to  one  end  of  the 
link  20.  The  cut-off  lever  is  counterweigh  ted,  so  that  when 
free  to  move  on  its  pivot  it  will  force  the  link  20  down  and 
close  the  supply  valve.  At  the  same  time  the  exhaust  valve 
will  be  opened,  as  the  two  valves  are  connected,  and  any  move- 
ment which  closes  one  opens  the  other.  As  soon  as  pawl  22 
has  been  raised  by  roller  25,  cut-off  lever  8  is  released,  closing 


86 


BLOCK    SIGNALS. 


Figs.  584-586 


the  supply  valve,  which  stops  the  flow  of  gas  Into  the  cylinder 
and  opens  the  exhaust  valve  and  allows  the  gas  which  has 
been  used  in  the  cylinder  to  escape. 

It  is  apparent  that  the  gas  has  been  used  only  to  raise  the 
cylinder,  not  to  hold  it  in  its  new  position.  This  latter  func- 
tion is  performed  by  the  clutch  lever  12,  which  is  suspended  on 
pivoted  bearing  36.  The  top  of  this  lever  has  a  nose-shaped 
projection  which  engages  a  latch  on  the  back  of  clutch  casting 
23.  The  lower  end  of  clutch  lever  12  carries  an  armature  for 
magnet  16,  and  when  the  magnet  is  energized  the  clutch  lever 
is  held  in  such  a  position  that  the  latch  on  casting  23  rests 
on  the  nose  of  clutch  lever  12  and  holds  the  signal  in  the 


Fig.  589  shows  the  controlling  valves  (9-10,  Figs.  584-586) 
in  detail.  Parts  18-19-20  are  the  same  as  those  of  correspond- 
ing number  in  Figs.  585-586.  Adjustable  connections  N  and  B 
are  attached  to  the  front  armature  and  to  rod  7  or  8.  The 
body  of  the  valve  E  has  a  cover  H ;  K  is  the  valve  itself, 
with  stem  connected  to  C,  and  L  is  the  valve  guard  and  seat ; 
F  is  a  washer ;  D  is  a  steel  ball  serving  as  a  check  to  retard 
the  exhaust  of  gas  from  the  cylinder  so  as  to  form  a  cushion 
between  the  cylinder  head  and  the  piston.  D  is  kept  from 
completely  blocking  the  passage  by  adjusting  screw  A.  Gas 
is  admitted  at  the  left  and  passes  up  and  over  L.  When 
K  is  raised  from  its  seat,  C  seats  at  O  and  gas  passes  around 


u 


Figs.  584-586.     Hall    Electro-Gas   Signal   Mechanism  for  Two-Arm    Signal    Mechanism. 


Names  of  Parts  of  Hall  Electro-Gas  Two-Arm  Signal  Mechanism.     Figs.  584-586. 


I-  Cylinder  13 

2  Piston  14 

3  Cylinder  Packing  15 

4  Operating  Rod  (Cylinder  Rod)  16 

5  Pressure  Gage  17 

6  Regulator  18 

7  Cut-off  Lever,  L.  H.  19 

8  Cut-off  Lever,  R.  H.  20 

9  Gas  Valve,  L.  H.  21 

10  Gas  Valve,  R.  H.  22 

11  Clutch  Lever,  L.  H.  23 

12  Clutch  Lever,  R.  H.  24 


Circuit  Closing  Rod  25 

Circuit  Closing  Rod  Spring  26 

Circuit  Closer  27 

Valve  Magnet  Coils  28 

Valve  Magnet  Armature  29 

Valve  Connector  30 

Valve  Lever  31 

Valve  Lever  Adjusting  Link  32 

Frame  33 

Cut-off  Lever  Pawl  34 

Clutch  Casting  35 

Buffer  Lever  Roller  36 


Cut-off  Lever  Roller 

Clutch  Casting  Latch 

Tank  and  Regulator  Connection 

Expansion  Chamber  Connection 

Expansion  Chamber 

Cylinder  Cwnection 

Signal  Rod  Clamp 

Clutch  Casting  Guide  Rod 

Clutch  Casting  Catch 

Gage  Connection 

Valve  Magnet  Cover 

Clutch  Lever  Shaft  Support 


clear  position.  When  the  magnet  becomes  de-energized  clutch 
lever  12  is  released  and  the  counterweight  of  the  signal,  fall- 
ing, causes  clutch  lever  12  to  fly  backward  on  its  pivot  36  a 
sufficient  distance  to  allow  the  latch  and  clutch  casting  23 
to  pass  the  projection  on  the  clutch  lever  12;  and  the  signal 
drops  to  the  stop  position.  The  escape  of  the  gas  or  air  from 
the  cylinder  through  the  exhaust  valve  is  so  regulated  that 
the  piston  and  cylinder  become  a  dash-pot,  preventing  any 
violent  drop  of  the  cylinder  when  the  signal  assumes  the 
stop  position.  Circuit  breaker  15,  used  to  control  the  distant 
and  other  circuits,  is  shown  in  Figs.  527-528.  It  is  operated 
by  rod  13  through  a  crank.  The  upper  end  of  rod  13  is 
bent  at  right  angles  and  has  a  lug,  as  shown.  Roller  25 
moves  13  up  by  striking  against  the  bent  top  or  down  by 
striking  the  lug.  Spring  14  will  pull  13  down  in  case  the 
lug  should  break.  Cut-off  lever  7  is  left-handed  and  8  is 
right-handed,  and  the  same  is  true  of  11  and  12. 

The  piston  and  cylinder  are  made  of  phosphor-bronze,  ground 
to  a  true  fit.  The  cylinder  being  inverted  and  moving  on  the 
piston,  it  can  have  a  solid  head,  certainly  preventing  the 
entrance  of  water.  Its  pedestal  has  a  brass  bushing. 


K  and  D  to  the  cylinder.  When  C  is  lowered  K  seats  and  is 
held  seated  by  the  pressure  of  the  gas.  The  exhaust  passes 
from  the  cylinder,  around  D  and  down  around  the  stem  of 
K  and  C  to  the  atmosphere. 

Fig.  583  is  an  enlarged  view  of  the  regulating  valve  6,  Figs. 
584-586,  though  in  those  illustrations  only  one  gage  is  shown 
instead  of  two.  The  single  gage  has  two  hands,  one  for  the 
high  pressure  and  one  for  low.  It  is  mounted  centrally  and 
a  pipe  leads  to  it  from  the  coupling  where  the  high  pressure 
gage  is  mounted  in  Fig.  585.  The  functions  of  the  various 
parts  and  the  operation  of  the  valve  are  as  follows :  Gas 
enters  the  valve  body  through  E,  which  is  connected  to  the 
high  pressure  gage  C,  and  reaches  valve  seat  F.  Before  the 
gas  is  turned  on,  the  adjusting  screw  I  is  unscrewed  so  that 
there  is  no  pressure  on  the  spring  II;  then  the  diaphragm  ,T 
tends  to  hold  the  hard  rubber  valve  disk  K  down  on  the 
seat  F,  and  when  the  gas  is  turned  on  prevents  it  from 
escaping  to  any  extent.  Then  the  adjusting  screw  I  is  screwed 
in.  This  puts  pressure  on  spring  H.  The  top  of  this  spring 
bears  on  the  flange  L  and  raises  it,  with  all  the  parts  con- 
nected to  it,  which  includes  the  center  of  the  diaphragm  J, 


Figs.  587-590 


BLOCK    SIGNALS. 


the  support  for  disk  holder  G,  the  disk  holder  M  with  the 
disk  K  and  the  center  of  the  slotted  diaphragm  N.  This 
operation  raises  the  hard  rubber  disk  K  off  the  seat  F  and 
allows  the  high  pressure  gas  to  flow  into  the  chamber  O.  The 
gas  continues  to  flow  into  the  chamber  O  and  fills  the  passage 
leading  to  the  low  pressure  gage  D,  which  indicates  the 
pressure.  It  flows  through  the  pipe  leading  to  the  expansion 
chamber,  29,  Fig.  448,  which  is  connected  at  B.  If  the  valves 
of  the  signal  mechanism  are  closed  the  gas  pressure  gradually 
Increases  in  O  and  the  expansion  chamber  until  it  becomes 
great  enough  on  the  diaphragm  J  to  force  it  down  and  com- 
press spring  H.  When  the  diaphragm  J  is  forced  down  by  the 
gas  pressure,  the  parts  attached  thereto,  including  the  sup- 
port for  disk  holder  G,  valve  disk  holder  M  and  the  hard 
rubber  valve  disk  K,  move  with  it.  When  the  hard  rubber 


dust  and  prevent  injury  to  the  couplings  and  valves  while  in 
transit,  and  has  a  safety  plug  which  will  blow  out  if  the 
pressure  should  become  dangerous.  One  tank  holds  enough 
gas  for  several  hundred  signal  movements.  Tanks  are  shipped 
as  needed  from  a  central  manufactory  and  a  reserve  tank  is 
kept  at  each  signal  post. 

Fig.  588  shows  the  local  wiring  for  an  electro-gas  mech- 
anism, when  used  in  the  normal  danger  systems  shown  iu 
Figs.  502-503.  It  is  similar  to  Fig.  522. 


ELECTRO-PNEUMATIC     SIGNAL. 

This  type  of  signal  involves  the  direct  application  of  com- 
pressed air  to  the  signal  shaft  through  the  medium  of  arms 
thereon,  which  are  connected  by  short  links  to  the  pistons  of 
two  cylinders  mounted  in  close  proximity  to  the  shaft ;  two 


U-4- 
i      i 


-3-IO\- 


Fig.    587.     Standard    Flask   for    Liquid    Gas.      New 
York  Central  &  Hudson  River. 


Shunt  on  LineRe/ay3 


Home  Cor? fro/ 


Fig.  588.     Wiring  for  Hall   Electro-Gas  Automatic          Figs.   589-590.     Controlling  Valve,   Electro-Gas   Signal. 
Block  Signal;  Normal  Danger,  Double  Track.  Hall  Signal  Company. 


valve  disk  is  forced  down  it  bears  on  the  top  of  the  valve 
seat  F  and  stops  the  flow  of  gas.  The  gas  pressure  required 
to  stop  the  flow  of  gas  is  determined  by  the  amount  of  pressure 
put  on  the  spring  by  the  adjusting  screw.  If  a  higher  working 
pressure  is  required,  the  adjusting  screw  I  is  screwed  in  further, 
putting  a  greater  pressure  on  the  spring  H,  making  necessary  a 
higher  gas  pressure  on  the  diaphragm  J  to  press  the  hard 
rubber  valve  disk  K  on  the  seat  F  and  stop  the  flow  of  gas. 
Unscrewing  the  adjusting  screw  reduces  the  pressure  on  the 
spring,  and  the  gas  has  less  pressure  to  overcome  in  order 
to  move  the  diaphragm  and  the  parts  attached  to  it ;  con- 
sequently a  lower  gas  pressure  stops  the  flow  of  gas  When- 
ever any  gas  is-  drawn  from  the  low  pressure  side  of  the 
regulating  valve,  the  pressure  is  reduced  and  the  spring  im- 
mediately forces  the  diaphraghm  and  parts  attached  to  it  up, 
which  raises  the  hard  rubber  valve  disk  off  the  seat  and 
allows  gas  to  flow  into  the  low  pressure  side  of  the  regulat- 
ing valve,  thus  keeping  the  pressure  on  that  side  practically 
constant. 

The  support  for  disk  holder  G  is  rigidly  attached  to  the 
center  of  diaphragm  J,  and  the  upper  end  of  the  support  is 
securely  fastened  to  the  valve  disk  holder  M  by  means  of  three 
screws,  thus  making  one  rigid  piece.  The  threaded  end  of  the 
valve  disk  holder  M  projects  through  a  hole  in  the  slotted 
diaphragm  N,  and  a  threaded  sleeve  is  screwed  down  on  the 
slotted  diaphragm  N,  firmly  clamping  it  between  the  sleeve 
and  the  valve  disk  holder  ;  thus  the  parts  in  which  the  hard 
rubber  valve  disk  are  held  are  centrally  guided  at  the  lower 
end  by  the  diaphragm  which  transmits  the  pressure  to  the 
spring,  and  the  upper  end  is  centrally  guided  by  a  diaphragm 
which  is  slotted  to  make  it  flexible,  and  also  to  allow  the 
pressure  to  become  equal  on  all  sides  of  it.  By  using  the  two 
diaphragms  to  guide  the  valve  disk  the  disk  must  always  seat 
in  exactly  the  same  place. 

Fig^  587  the  gas  tank,  is  made  of  steel  to  withstand  a 
pressure  of  3,000  Ibs.  per  sq.  in.  It  has  a  cover  to  exclude 


pneumatic  valves  attached,  one  to  each  cylinder,  and  two  elec- 
tro-magnets, one  for  the  operation  of  each  valve. 

The  short  stroke  cylinder  causes  the  movement  to  the  45-deg. 
position,  and  carries  the  piston  of  the  long  stroke  cylinder  idly 
to  midstroke. 

A  further  movement  of  the  signal  toward  the  90-deg.  position 
is  not  possible  by  the  piston  of  the  short  stroke  cylinder,  which 
has  seated  when  the  signal  is  at  45  deg.  upon  the  packing  ring 
in  the  lower  cylinder  head  to  minimize  loss  of  pressure  from 
escape  through  the  packing  rings  of  the  piston. 

Movement  of  the  signal  from  45  deg.  to  90  deg.  is  effected 
solely  by  the  long  stroke  cylinder.  Pressure  is  admitted  to  this 
cylinder  (with  its  piston  at  mid-stroke)  through  the  electro- 
magnetic valve  attached  to  it,  and  after  operation  seats  the  pis- 
ton of  this  cylinder  upon  the  packing  ring  in  its  lower  head, 
as  in  the  case  of  the  short  stroke  piston,  to  retard  pressure 
losses  through  the  piston  rings. 

This  operation  carries  the  arm  upon  the  shaft  by  which  the 
signal  was  moved  to  45  deg.  by  the  short  stroke  cylinder,  down- 
ward through  the  slotted  end  of  the  piston  rod  of  that  cylinder. 

By  de-energizing  the  magnet  of  the  valve  of  the  long  stroke 
cylinder  the  air  is  permitted  to  escape  from  that  cylinder  and 
the  signal  under  the  influence  of  gravity  returns  to  the  45-deg. 
position  when  the  arm  on  the  shaft  which  engages  the  slotted 
piston  rod  of  the  short  stroke  cylinder  is  arrested  in  its  up- 
ward movement  by  virtue  of  its  having  traveled  through  the 
slotted  part  of  the  piston  rod  and  has  a  tendency  to  move  that 
rod  with  it  in  the  further  movement  of  the  signal  from  45  deg. 
to  0  deg.  This  it  will  be  unable  to  do  if  the  pressure  still 
remains  above  the  piston  and  the  signal  will  consequently  be 
retained  by  the  short  stroke  cylinder  at  45  deg. 

Should  the  pressure  be  released  from  this  short  cylinder  its 
piston  will  move  upwards  under  the  signal's  weight  to  the  end 
of  its  stroke,  when  the  signal  will  be  at  0  deg.,  or  horizontal. 

It  is   characteristic  of  this  signal    that  the  air  supply  to  the 


88 


BLOCK    SIGNALS. 


Figs.  591-595 


long  stroke  cylinder  is  drawn  through  its  valve,  not  direct 
from  the  air  main  as  in  the  short  stroke  cylinder,  but  from 
the  pressure  chamber  above  the  piston  of  the  latter  cylinder. 

This  makes  It  impossible  to  operate  the  signal  from  the  hori- 
zontal position  by  the  long  stroke  cylinder,  if  for  any  reason 
its  valve  should  be  operated  In  advance  of  that  of  the  short 


Fig-  591-     Electro-Pneumatic  Three-Position  Top  Post 
Signal. 

stroke  cylinder;  and  the  control  of  the  valve  of  the  long  stroke 
cylinder  electrically  by   position   of  the  signal   when  moved  to 
45  deg.  by  the  short  stroke  cylinder  Is  not  necessary  with  this 
system  of  piping  save  as  a  precautionary  measure. 
This  method  of  piping  will   permit  the  signal   to  move  from 


vertical  (90  deg.)  to  horizontal  by  de-energization  of  the  mag- 
net of  the  short  stroke  cylinder  alone  and  irrespective  of  the 
energized  state  of  the  valve  magnet  of  the  long  stroke  cylinder, 
the  pressure  and  exhaust  of  both  cylinders  being  under  the 
immediate  control  of  the  valve  of  the  short  stroke  cylinder  at 
all  times. 

A  positively  acting  circuit  controller,  easily  demountable  and 
accessible  to  inspection,   is  attached  to  the  face  of  the  mechan- 


FRONT  VEW  COVER  REMOVED 


SECTIONAL   SIDE  VIEW 


Figs.  592-593.     Pole  Changer  and  Circuit  Controller  for 
Lower  Quadrant  High  Signals. 

Ism  case  and  operated   by  direct  coupling  from  the  semaphore 
shaft. 

This  device  Is  adapted  to  actuate  the  contacts  at  any  period 
of  the  signal's  movement  by  simply  shifting  the  cams  upon  the 
square  shaft  upon  which  they  are  mounted. 


Figs.   594-595-     Electro-Pneumatic    Signal    Mechanism.     Union   Switch   &  Signal  Company. 


Figs.  596-598 


BLOCK    SIGNALS. 


89 


Fig.  597  illustrates  the  pin  valve  and  its  magnet  used  to 
control  electro-pneumatic  signals,  made  by  the  Union  Switch 
&  Signal  Co.  The  magnet  is  of  the  "iron-clad"  type. 
Between  the  pole  piece  and  the  armature  there  is  a  spring  5, 
which  assists  in  releasing  the  armature  when  current  is 
withdrawn.  The  stem  4  of  the  armature  passes  down  through 
the  center  of  the  magnet  and  rests  on  the  stem,  7,  of  the 
pin  valve.  The  armature  stem  has  a  beveled  end  to  seat  in 
the  opening  below  when  it  is  depressed.  The  pin  valve  is  held 
against  its  seat,  B,  by  the  pressure  of  the  air  at  E  and  also 


magnet,  B,  and  the  pin  valve.  The  cylinder,  1,  and  the  bottom 
head,  2,  are  bolted  to  the  main  head  as  shown.  Piston  4, 
moving  in  the  cylinder,  is  forced  down  by  the  admission  ct 
compressed  air  at  the  top  and  motion  is  transmitted  to  the 
signal  by  means  of  the  piston  rod  9.  This  Is  connected  to 
the  "up  and  down  rod"  of  the  signal  through  a  balance  lever 
(Figs.  594-595).  The  piston  rod  is  secured  to  the  piston  by 
a  universal  ball  and  socket  joint,  and  disk  8,  which  is  screwed 
into  the  piston,  forms  the  lower  portion  of  this  joint.  Washer 
11  rests  on  the  bottom  cylinder  head  and  keeps  out  dirt. 


15 


Names  of  Parts  of  Fig.  598. 

1  Cylinder 

2  Bottom  Cylinder  Head 

3  Top  Cylinder  Head  and  Bracket 

4  Piston 

5  Cage  for  Piston  Rings 

6  Piston  Ring 

7  Lock-Nut  for  Piston  Ring  Cage 

8  Ring  Nut 

9  Piston  Rod 

10  Jaw 

11  Washer 

12  Leather  Gasket 

13  Fiber  Gasket 

14  Oil  Plug 

15  Dozvel  Pin 

16  Stud  for  Cylinder 
B  Pin  Valve  Magnet 


Figs.    596-598.     Details   of   Electro-Pneumatic   Cylinder,  Magnet  and   Valve  for  Semaphore    Signal. 

Switch   &  Signal  Company. 


The   Union 


by  the  spring  8.  E  is  connected  to  the  source  of  air  supply. 
When  the  magnet  is  energized,  the  armature  is  attracted 
and  its  stem  presses  down  and  unseats  the  pin  valve.  This 
admits  air  to  the  chamber  C.  At  the  same  time  the  end  of 
the  armature  stem  seats  at  A,  so  that  air  cannot  escape 
through  the  exhaust  port  D.  When  the  magnet  is  de-energized 
the  various  parts  return  to  their  normal  position,  as  shown. 
This  allows  air  to  escape  from  C  to  the  atmosphere  through 
D  and  prevents  entrance  of  air  from  E,  through  B,  to  C. 

Figs.  596  and  598  show  an  electro-pneumatic  cylinder  for 
a  semaphore  signal.  The  cylinder  head  3  with  its  bracket  is 
fastened  to  the  support  at  15.  To  this  is  clamped  the  valve 


When  compressed  air  is  admitted  to  the  chamber  C  (Fig. 
597),  it  passes  through  the  diagonally  arranged  port  N,  to 
the  space  above  the  piston  and  forces  the  piston  down,  clear- 
ing the  signal.  When  the  magnet  at  B  is  de-energized,  the 
air  is  shut  off  and  chamber  C  is  connected  to  atmosphere 
through  D  ;  the  air  in  the  cylinder  above  the  piston  escapes, 
allowing  it  to  assume  its  normal  position,  as  shown,  putting 
the  signal  in  the  stop  position.  This  it  does  by  gravity. 

In  Figs.  599  and  600  is  shown  an  electro-pneumatic  mech- 
anism for  operating  a  three-position  semaphore.  It  consists 
essentially  of  two  of  the  ordinary  two-arm  mechanisms  super- 
imposed one  upon  the  other.  The  upper  cylinder  is  shorter 


go 


BLOCK    SIGNALS. 


Figs.  599-602 


28 


Names    of   Parts   for    Figs.    599-600. 


Lower  Cylinder 

Upper  Cylinder 

Bottom  Head  for  Lower  Cylinder 

Bracket 

Top   Cylinder  Head 

Piston 

Cage  for  Piston  Rings 

Piston  Ring 

Lock-nut  for  Lower  Piston  Ring  Cage 

Lock-nut  for  Upper  Piston  Ring  Cage 

Ring  Nut  for  Lower  Cylinder 

Ring  Nut  for  Upper  Cylinder 

Stuffing  Box  Ring  Nut 

Upper  Piston  Rod 

Lozver  Piston  Rod 

Jaw 

Washer 

Leather  Gasket 

Leather  Packing 

Fiber  Gasket 

Gland  for  Stuffing  Box 

Stuffing  Box  Spring 

Pipe  Connection 

Three-way  Cock  and  Union 

Air  Inlet  for  Lozver  Cylinder 

Oil  Plug 

Dozvel  Pin 

Stud  for  Upper  Cylinder  { 

Stud  for  Lower  Cylinder 

Upper  Pin  Valve  Magnet  , 

Loiver  Pin  Valve  Magnet 


Figs.  599-600.     Electro-Pneumatic  Cylinders  for  Three- 
Position   Semaphore,    Tandem    Movement. 


i 

ft 

i    i 

Hi.                         ' 

Uf 

^W**y          . 

-pi 

9 

JL.,- 

i 
i 
i 

JT 

\- 

^> 

^!   , 

r_z-  —  i 

!  ^  '• 

i 

A         • 

|  0,r-<Kf'On 

aS  TtvSS/C 

Fig.    601.     Wiring    for     Electro-Pneumatic    Automatic 
Block    Signal;    Distant   Signals    Controlled   by 
Polarized  Track  Circuits;   Primary  Bat- 
tery.    Pennsylvania  Railroad. 


Fig.  602.     Same  as  Fig.  601,  but  with  Storage  Battery 
in   Place  of  Primary. 


than  the  lower.  The  piston  rod  of  the  upper  cylinder  rests 
on  top  of  hut  is  not  connected  to  the  piston  of  the  lower 
cylinder.  The  upper  cylinder  is  used  to  move  the  signal 
through  the  first  half  of  its  stroke,  that  is,  from  stop  to 


caution,  and  the  second  half  is  accomplished  by  the  action  in 
the  lower  cylinder,  the  piston  of.  which  moves  away  from 
the  upper  piston  rod.  This  rod  acts  as  a  stop  when  the  signal 
is  returned  from  the  clear  to  the  caution  position. 


Figs.  603-605 


BLOCK    SIGNALS. 


ALTERNATING  CURRENT  SIGNALING 


DISCUSSION'. 

In  the  signaling  of  roads  employing  steam  as  the  motive  power 
the  track  circuit  is  comparatively  simple  (Fig.  484).  When, 
however,  the  rails  are  required  to  carry  the  heavy  currents 
called  for  by  electric  traction,  the  track  circuit  problem  be- 
comes more  difficult. 

First:  Because  the  rails  must  be  made  electrically  con- 
tinuous throughout  to  serve  as  a  return  for  the  propulsion 
current  and  at  the  same  time  must  be  divided  into  electrically 
insulated  sections  as  far  as  signaling  current  is  concerned. 

J  r-i  A* •— 'J 


Pig.  603  shows  the  "single  rail"  circuit,  which  is  the  simplest 
form  of  a.  c.  track  circuit,  and  is  only  used  where  it  is  per- 
missible to  give  up  one  of  the  rails  for  signaling  purposes 
only.  It  is  best  adapted  to  roads  employing  direct  current  for 
propulsion.  The  rail  A  is  continuous  throughout  and  Is  used 
as  a  return  for  the  traction  current.  Rail  A'  is  insulated  at 
the  joints  J-J,  and  is  used  only  for  the  signaling  current.  P 
is  an  alternating  current  relay  of  the  two-phase  type  described 
above.  When  both  windings  are  energized  the  motor  revolves, 
and  being  geared  to  the  contact  closes  it,  the  contact  acting 

J 


Power   Line 


T1 


Power  Line 


Single   Rail  Circuit. 


Double  Rail  Circuit.     Iron  Core  Reactance  Bonds. 


Power  Line 


IWWi 


WWM 


Center  Fed  Double  Rail  Circuit. 
Figs.   603-605.     Alternating 

Second:  Because  the  traction  current  flowing  in  the  rails 
would  tend  falsely  to  operate  the  track  relays  were  they  of 
the  usual  direct  current  type;  hence,  the  necessity  of  employing 
relays  which  are  unaffected  by  the  traction  currents  and  supply- 
ing a  signaling  current  of  the  right  character  to  operate  them. 

Third:  Because  for  traction  purposes  cross-bonding  between 
tracks  is  necessary  at  frequent  intervals,  thus  influencing  the 
arrangement  of  track  circuits. 

Figs.  603-604  show  two  types  of  track  circuits,  which 
fulfill  the  requirements  imposed  by  electric  traction.  In  both 
of  these,  alternating  current  is  used  for  signaling  purposes.  The 
track  relay  (Figs.  607-608  is  operated  by  a  small  two-phase 
induction  motor,  one  winding  of  which  is  energized  through  the 
track  rails  and  the  other  winding  direct  from  the  power  line. 
This  relay  is  not  affected  by  direct  current,  no  matter  what 
frequency,  within  reasonable  limits,  is  used  for  signaling  and 
is  not  affected  by  alternating  current  if  a  frequency  distinc- 
tively different  from  that  of  the  traction  current  is  used.  For 
in  a  two-phase  induction  motor,  if  the  phase  in  one  set  of  field 
coils  varies  greatly  from  that  in  the  other,  the  motor  will  not 
operate.  As  both  sets  of  fields  in  the  two-phase  induction 
motor  relay  are  fed  from  transformers  on  the  same  single-phase 
power  line,  some  agency  must  be  provided  to  produce  different 
angles  of  lag  in  the  two  secondary  circuits,  otherwise  the  relay 
would  not  act.  Such  agency  exists  in  the  different  apparent  re- 
sistances of  the  line  circuit  and  the  track  rails.  Also  in  in- 
ductive and  impeding  effects  of  the  rails  and  bonds.  It  is  not 
necessary,  however,  to  use  two-phase  motor  relays.  Single- 
phase  induction  relays  will  give  satisfactory  results.  But 
where  the  track  circuit  is  long  and  leakage  heavy  it  is  better 
to  use  two-phase  relays,  as  they  have  a  good  torque  with  a 
small  current  from  the  track.  They  are  more  expensive,  how- 
ever, than  single-phase  relays  and  add  some  complication  to 
the  wiring. 

On  account  of  the  fact  that  alternating  current  is  used  for 
signaling  and  that  either  one  or  both  of  the  rails  may  be 
used  for  the  propulsion  current  return,  the  circuits  are  known 
as  "Single  Rail  a.  c.  Track  Circuits,"  or  "Double  Rail  a.  c. 
Track  Circuits." 


Iron  Core  Reactance   Bonds. 
Current  Track   Circuits. 

as  a  stop  to  the  movement  of  the  armature,  which  now  ceases 
to  turn,  but  bears  against  the  contact,  holding  it  closed.  The 
signal  S  (using  current  from  the  transformer  T)  operates  as 
already  described  in  connection  with  Fig.  484. 

When  a  train  enters  the  track  circuit  the  current  from 
transformer  T'  is  shunted  out  of  the  relay,  as  already  de- 
scribed in  the  ordinary  direct  current  track  circuit  and,  although 
current  from  the  transformer  T  still  continues  to  flow  through 
one  winding,  the  motor  loses  its  torque,  the  armature  is  re- 
volved in  reverse  direction  by  gravity  and  the  relay  contact  opens. 

R  indicates  a  resistance  so  proportioned  that  the  drop  in 
potential  in  rail  A,  caused  by  the  flow  of  traction  current, 
will  not  cause  injurious  currents  to  flow  through  the  relay  P, 
or  the  secondary  at  the  track  transformer  T'.  (See  Boston 
Elevated  description.)  The  resistance  also  prevents  an  exces- 
sive flow  of  current  from  transformer  T',  "when  a  train  is 
standing  at  the  transformer.  These  resistances  are  of  the 
non-inductive  type.  They  are  constructed  of  cast-iron  grids,  and 
the  form  of  these  cast-iron  resistance  grids  is  such  that  current 
passing  through  them  produces  no  magnetic  effects.  The  grids 
are  mounted  on  two  or  more  rods,  which  are  provided  with 
the  necessary  insulation  and  can  be  built  up  to  any  desired 
resistance. 

T  and  T'  are  stepdown  transformers,  which  reduce  the 
voltage  from  the  power  line  to  that  required  for  track  circuit 
and  other  purposes.  Cross-bonding  for  traction  purposes  may 
be  made  at  any  point  on  the  continuous  rail  A. 

Fij;'-  604  shows  a  type  of  a.  c.  track  circuit,  in  which  both 
rails  are  retained  for  propulsion  purposes,  but  in  which  cross- 
bonding  to  adjacent  tracks  can  occur  only  at  the  ends  of  track 
circuits.  This  type  of  track  circuit  is  especially  adapted  to 
roads  where  the  traffic  is  very  heavy  and  the  block  of  medium 
lengths;  and  is  applicable  to  either  a.  c.  or  d.  c.  traction.  As 
shown,  both  rails  are  insulated  at  the  signal  locations  by  the 
joints  J  and  are  made  continuous  as  concerns  the  traction 
current  by  the  iron  core  reactance  bonds  B. 

The  reactance  bonds  B  consist  of  a  few  turns  of  very 
heavy  copper,  wound  around  a  laminated  iron  core  and  so 
connected  to  the  rails  that  the  traction  current  in  each  rail 


BLOCK    SIGNALS. 


Figs.  606-609 


flows  through  one-half  the  bond  in  such  manner  as  to  have 
no  magnetic  effect  unless  more  current  is  flowing  in  one  rail 
than  the  other,  in  which  case  there  would  be  a  tendency  to 
saturate  the  iron  core  and  thus  reduce  the  reactance  of  the 
bond.  This  tendency  is,  however,  limited  by  an  air  gap  in  the 


Fig.  606.     Universal  Model  "2-A"  Base-of-Mast   Signal 
Mechanism.     A.  C.   Control. 

magnetic  circuit.  This  difference  of  current  is  called  unbalanc- 
ing. This  can  be  better  understood  if  it  is  noted  that  pro- 
pulsion current  flows  in  the  same  direction  in  each  rail. 
Therefore  the  bond  is  in  effect  two  electro-magnets  of  equal 
strength  wound  on  the  same  cores  in  opposition.  Thus  the 
magnetic  effect  due.  to  direct  current  in  one  winding  will 
neutralize  that  in  the  other  unless  more  current  should  flow 
in  one  rail  than  in  the  other.  If  the  iron  core  were  continuous 
the  effect  of  an  unbalanced  propulsion  current  would  be  to 
shift  the  neutral  magnetic  point  along  the  core  a  distance 
proportional  to  the  amount  of  unbalancing.  For  this  reason 
the  air  gap  is  introduced  in  the  magnetic  circuit,  and  the 
wider  the  gap  the  less  the  neutral  point  will  shift  for  a  given 
amount  of  unbalancing  because  air  is  a  poor  conductor  of 


Fig.    607.     Universal    Polyphase    Relay.     Model    2, 
Form  A   (6-way). 

magnetic  lines  of  force  compared  with  iron.  But  the  wider 
the  air  gap  is  made  tin-  lower  becomes  the  inductive  effect 
of  the  iron  (which  is  a  maximum  when  the  core  is  continuous), 
and  the  greater  the  leakage  of  alternating  current  across  the 
rails,  due  to  the  impaired  reactance. 

The    relay    can    be    connected    directly    to    the    rails    ns    shown 


in  Fig.  604  without  the  chance  of  having  excessive  amounts 
of  propulsion  current  flow  through  it,  since  in  the  iron-core 
reactance  bond  the  voltage  drop  in  one-half  of  the  coils  neutra- 
lizes that  in  the  other.  In  the  case  of  traction  cross-bonding 
to  adjacent  tracks  the  connection  for  such  cross  bonds  to  the 
•rails  may  be  made  only  at  bond  locations  and,  therefore,  the 
permissible  length  of  such  track  circuits  will  be  limited  by  the 
required  frequency  of  cross-bonding.  The  size  of  the  bond,  for 
a  given  reactance,  is  dependent  upon  the  amount  of  traction 
current  to  be  carried  and  the  amount  of  unbalancing  which  has 
to  be  taken  care  of. 

The  track  relay  P  and  its  operation  are  the  same  as  de- 
scribed for  Fig.  603  and  the  transformers  and  the  reactance 
grids  are  of  the  same  general  character.  With  fair  ballasting 


Iff          fit  It 

m    *m    *    m 


-     f 


Fig.    608.     Universal    Polyphase    Relay. 
Form  A   (4-way). 


Model   2, 


conditions,  track  circuits  of  this  type  up  to  7,000  ft.  in  length 
have  been  operated  successfully.  It  is  possible,  however,  to 
operate  with  equal  satisfaction  track  circuits  of  twice  this 
length,  by  placing  the  energy  transformer  T'  at  the  center  of 


Fig.  609.     H3  Transformer. 

the  section  and  using  the  transformer  bonds  B  and  the  track 
relays  P  at  both  ends,  the  signal  control  being  carried  through 
the  contacts  of  both  these  relays  in  series  as  shown  in  Fig.  605. 
Aside  from  the  track  circuit,  above  described,  the  other 
devices  incident  to  a  complete  signal  system,  such  as  the  sig- 
nals, signal  operating  batteries,  line  relays,  method  of  control, 


Figs.  610-612 


BLOCK    SIGNALS. 


93 


etc.,  need  be  no  different  for  electrical  roads  from  those  used 
on  steam  roads  ;  but  since  a  power  line  must  be  strung  the  en- 
tire length  of  the  system  to  supply  the  track  circuits  the  signal 
movements,  line  relays,  lights,  etc.,  can  as  well  be  designed  to 
operate  from  alternating  current,  thus  requiring  but  one  set 
of  generating  apparatus  and  also  but  one  power  distribution 
system. 

CUMBERLAND    VALLEY    INSTALLATION. 

The  General  Railway  Signal  Company  installed,  during  1911, 
76  Model  "2A"  signals  on  a  section  of  the  Cumberland  Valley 
Railroad  between  .Harrisburg,  Pa.,  and  Mason-Dixon,  a  distance 
of  about  68  miles.  Twenty-five  cycle,  single  phase  alternating 
current  is  used  throughout  for  the  operation  of  signals  and  track 
•circuits,  and  for  the  lighting  of  signals,  station  buildings,  etc. 
The  signaled  territory  includes  seven  interlocking  plants,  elec- 
trical and  mechanical,  through  which  standard  track  circuit  ap- 
paratus and  signals  are  used.  Fig.  610  illustrates  one  of  the 
Model  "2A"  interlocking  signals. 

Energy    for    the   operation    of    the    signal    system    is    obtained 
rom   a   commercial  power   house  located   at   Lemoyne  and   from 
railroad    company's    plant    at    Chambersburg.      At    Lemoym- 


Fig.    610.      Model    "2A"    A.    C.    Interlocking    Signal. 
Cumberland  Valley  Railroad. 

only  60-cycle  current  was  available  and,  therefore,  two  fre- 
quency changer  sets  were  installed,  one  of  which  is  held  for 
emergency  use.  Two  22i/(>-k.  v.  a.  transformers  step  the  current 
generated  by  the  power  station  at  370  volts  up  to  the  power 
line  voltage  of  3,300.  The  power  lines  extend  in  both  di- 
rections and  are  so  connected  through  fusible  plug  cutouts  to 
the  power  station  that  either  branch  may  be  disconnected. 

The  railroad  company's  power  station  generates  370-volt, 
25-cycle,  three-phase  current,  the  signal  current  being  taken 
off  one  leg  of  the  three-phase  circuit  to  two  50-k.  v.  a.  trans- 
formers (one  for  emergency  use.)  The  power  lines  are  pro- 
tected in  a  manner  similar  to  that  used  at  Lemoyne. 

At  the  signal  locations  type  "H"  transformers  step  the  cur 
rent  down  from  the  power  line  voltage  to  55  volts,  which 
is  used  for  signal  and  switch  indicator  operation,  for  track  relay 
locals  and  for  the  primary  of  the  track  transformers.  The 


transformers  have  a  possible  variation  of  10  per  cent  to  take 
care  of  the  drop  at  the  points  farthest  from  the  power  supply. 
The  capacfty  of  the  transformers  Is  400  v.  a.  Fusible  plug 
cutouts  and  lightning  arresters  protect  the  transformer  primary. 
The  track  transformers  are  of  a  smaller  size  than  the  track 
relays,  which  permits  their  being  housed  in  the  relay  boxes. 
They  have  a  capacity  of  40  v.  a.  and  give  secondary  voltages, 
ranging  from  2  to  10  volts.  In  automatic  territory  one  such 
transformer  is  used  per  track  circuit,  but  through  the  inter- 
locked sections  several  track  circuits  may  be  fed  by  one  trans- 


Fig.  611.    Automatic  Signal  Location.    Alternating  Current 
Signals  on  Cumberland  Valley. 

former.  A  9/10-ohm  resistance  unit  with  taps  giving  variable 
resistances  is  placed  in  series  with  the  transformer  leads  to 
the  track,  to  prevent  excessive  flow  of  current  through  the 
transformer  when  a  train  is  standing  at  the  location. 

The  track  relays  are  Model  2,  Form  A,  polyphase.  They 
are  of  the  three-position  type,  wireless  control,  operating  in 
one  direction  to  clear  the  signal  to  the  45-deg.  position  and 
in  the  reverse  direction  for  the  90-deg.  position  of  the  signal; 
when  shunted  they  stand  in  the  neutral  position  with  their 
contacts  open.  The  polarity  of  the  track  circuit  is  reversed  by 
a  pole  changer  on  the  signal  in  advance  reversing  the  55-volt 
primary  leads  on  the  (rack  transformer  for  the  section  in  ques- 
tion. Through  interlocking  plants,  however,  the  track  circuits 
employ  a  two-position  relay,  which  is  equipped  with  an  indi- 


Fig.    612.      Automatic    Signals,    Cable    Post,    Transmission 
Line  and  Relay   Box.     Cumberland  Valley. 

eating  blade  and  located  in  the  tower  in  view  of  the  operator. 

The  automatic  signals  are  the  three-position,  upper  quadrant 
Model  "2 A",  with  a  staggeied  marker  light.  The  signal  is 
controlled  locally  through  the  track  relay  for  the  section  in 
advance  of  the  signal.  It  operates  on  55  volts  requiring  ap- 
proximately two  amperes  to  clear  the  blade. 

The  switch  indicators  are  of  standard  <J.  R.  S.  polyphase  con- 
struction, operating  on  55  volts,  the  windings  being  connected 
in  split  phase  relation  so  that  but  one  control  connection  to 
the  indicator  is  required.  The  control  circuit  is  broken  through 
the  circuit  breakers  on  the  proper  signals. 

The  relay  boxes  are  of  wood  built  in  one,  two  and  three-way 
sizes,  and  clamped  to  the  signal  masts  as  shown  in  Figs. 
610-612.  They  are  equipped  with  a  fuse  and  terminal  board 
to  provide  suitable  connections  for  the  signal,  relay  and  track 
transformer  circuits. 


94 


BLOCK    SIGNALS. 


Figs.  614-015 


SIGNALS  FOR  ELECTRIC  RAILWAYS 


NACHOD   SIGNAL,    SYSTEM. 

The    Nachod    signal    system    of    automatic    block    signals    for 


electric  railways,  type  CD,  Is  for  permissive  signaling  on 
single-track  lines  operating  in  both  directions,  with  turnouts 
or  sidings  at  passing  points.  It  gives  both  facing  and  rear 
protection,  though  without  distant  signals.  The  signal  indica- 
tions are  controlled  not  by  a  continuous  track  circuit,  which 
may  not  be  easily  applied  on  account  of  the  traction  current 
in  the  rail,  but  by  the  passage  of  the  car  or  train  past  a 
given  point  at  which  a  contact  device  is  located.  This,  with- 
out moving  parts,  may  be  a  short  section  of  third  rail,  an  in- 
sulated track  section,  or  a  trolley  contactor.  i 

The  system  is  adapted  either  for  single-end  sidings,  for 
through  type  turnouts,  or  for  curve  protection  In  both  direc- 
tions, the  arrangement  of  the  signal  apparatus  on  the  right- 
of-way  being  shown  approximately  in  Fig.  614  for  a  through 
type  turnout.  There  is  a  distance  of  from  one  to  two  spans 
between  the  trolley  contactor  and  the  signal  aspect;  which  is 
in  advance.  The  signal  Is  constructed  to  indicate  affirmatively ; 
that  Is,  every  passage  of  the  car  under  the  contactor  must  make 
some  change  on  the  aspect,  visible  to  the  motorman,  to  prove 
to  him  that  his  car  has  caused  the  mechanism  to  operate. 


SYSTEMS 

with  no  cars  in  the  block,  with  the  revolving  switch  in  a  cer- 
tain position,  they  will  be  restored  to  neutral  when  the  same 
number  of  cars  have  left  the  block  as  have  entered.  The  latter 
magnet  also  operates  the  white  color  disk,  and  the  left  lower 
magnet  H,  the  red  color  disk.  The  right-hand  one,  C,  is  the 
clearing  magnet.  Behind  this  magnet,  visible  in  this  view, 
is  the  no-voltage  magnet  N  to  prevent  change  of  signals 
on  failure  of  line  voltage.  To  the  left,  in  Fig.  618,  will  be 
seen  the  resistance  rods  vertically  mounted  with  contact  bands 
for  adjustable  taps.  The  entire  unit  depends  from  a  contact 
board  having  terminal  studs  which  impinge  upon  phosphor 
bronze  spring  contact  strips  in  the  upper  case.  By  this  means 
a  relay  may  be  removed  by  taking  out  three  bolts,  and  a  spare 
one  substituted  without  touching  the  wiring  in  any  manner. 

Some  unusual  features  of  this  relay,  which  is  in  fact  the 
heart  of  the  signal  system,  are,  in  the  first  place,  the  use 
of  partially  iron-clad  substantial  plunger-type  magnets  Instead 
of  the  delicate  pivoted  armature  type,  reducing  wear  and  the 
possibility  of  sticking,  since  the  power  for  operation  is  not 


tS*r-y  /OOO  ft. 

Fig.  614.     Wiring  Diagram  for  Through  Type  Turnout. 

The  apparatus  for  one  block  of  single  track,  as  shown  in 
Fig.  614,  consists  of  two  signal  boxes  and  four  contactors — 
although  two  might  be  used — -and  two  line  wires  connecting 
the  stations. 

The  apparatus  may  be  broadly  divided  into  three  parts : 
(1)  the  signal  aspect,  consisting  of  lights  and  color  disks;  (2) 
the  Intermediate  mechanism,  or  relay,  which  converts  the 
transient  current  impulses,  caused  by  the  passage  of  the  car 
under  the  contactor,  into  signal  indications,  and  (3)  the 
controlling  mechanism,  as  the  trolley  contactor. 

The  aspect  is  given  by  lights  and  color  disks  simultaneously, 
the  three  indications  being  no  light  and  no  disk;  a  white  light 
and  a  white  disk;  a  red  light  and  a  red  ilixk. 

The  signal  box  forming  the  aspect  is  a  substantial  weather- 
proof cast-iron  case  of  compact  and  pleasing  contour.  The 
lower  part  Is  an  oil  tank  which  may  be  removed  by  three  bolts 
so  as  to  expose  the  relay.  The  upper  part  is  attached  to 
the  pole  by  hangers,  and  contains  the  lights  and  disks,  which 
are  actuated  by  means  of  the  relay  magnets.  The  magnet 
connection  is  through  a  push  rod  so  that  there  is  no  shock 
transmitted  to  the  disk  by  the  quick  motion  of  the  magnet 
plunger.  These  disks  are  of  enameled  aluminum,  counter- 
weighted  to  fall  to  indication  by  gravity.  Only  one  lamp  is 
lighted  at  a  time,  at  which  time  the  disk  of  the  same  color 
rises  to  an  indicating  position,  and  is  viewed  through  the  clear 
glass  roundel  In  the  hinged  front  of  the  box.  Below  this 
there  are  openings  for  a  white  and  a  red  semaphore  lens 
for  the  lamps.  It  will  be  seen  that  the  disk  not  indicating 
acts  to  screen  from  cross  illumination  the  lens  not  indicating. 

The  relay  Is  attached  to  the  upper  case  by  three  bolts  which, 
when  removed,  allow  It  to  drop  away,  disconnecting  automat- 
ically both  the  electrical  contracts  and  the  push  rods  from 
the  color  disks.  This  unit,  shown  in  Fig.  618,  consists  of  five 
magnets,  the  upper  pair  of  which  counts  the  cars  by  a  ratchet 
and  pawl  mechanism ;  each  entering  car  operating  the  left- 
hand  magnet  A  (Fig.  617),  to  revolve  the  ratchet  wheel 
and  its  attached  revolving  switch  one  notch  in  the  counter- 
clockwise direction,  and  each  leaving  car  actuating  the  right- 
hand  magnet  D  to  move  the  ratchet  wheel  one  notch  in  the 
opposite  direction.  Thus,  if  the  signals  are  neutral  or  normal. 


Fig.  615.     Signal  Box,  Showing  Method  of  Suspension. 

minute,  but  may  be  as  great  as  desired.  Contacts  are  made 
and  broken  by  the  simple  rectilinear  movement  of  the  plungers, 
without  pivots  or  multiplying  levers,  there  being  phosphor 
bronze  spring  fingers  pressing  against  brass  rings  separated 
by  Insulating  material.  The  alignment  of  parts  is  through 
finished  metal  surfaces.  The  most  novel  feature  of  the  design, 
however,  is  the  immersion  of  the  entire  relay  in  a  tank  of 
transformer  oil.  By  this  means  not  only  is  continuous  lubri- 
cation provided  and  corrosion  prevented,  but  the  relay  Is  sealed 
against  the  entrance  of  foreign  matter,  dust,  insects,  etc. 
Moreover,  the  oil  acts  to  cushion  th»  variable  magnet  blows 
which  might  tend  otherwise  to  loosen  the  screws.  Further- 
more, the  high  insulating  power  of  the  oil  greatly  reduces 
damage  by  lightning,  which  has  always  been  a  serious  menace 
in  connection  with  such  signals,  and  it  also  permits  parts  of 
opposite  polarity  to  be  brought  closer  together  than  In  air, 
thereby  resulting  in  a  more  compact  design.  By  .the  cooling 
properties  of  the  oil,  which  transmits  the  local  heat  from  the 
coil  to  the  entire  tank  for  radiation,  the  range  of  the  voltage 
operation  is  increased,  since  enough  current  for  positive  opera- 
tion may  be  used  for  abnormally  low  voltages,  and  yet  the 
coll  will  not  be  overheated  with  the  normally  high  voltage. 
The  life  of  the  contact  fingers  Is  enormously  increased  by  the 
quenching  of  the  arc  under  oil,  so  that  altogether  the  very 
great  advantages  due  to  oil  cooling  and  oil  insulating,  so  long 
used  In  transformers,  together  with  that  of  the  oil-break 
switches,  are  obtained. 

Instances  are  on  record  where  signals  with  such  relays 
have  operated  for  a  year  at  a  time  with  no  attention  whatever. 

The  trolley  contactor  shown  in  Fig.  616  consists  of  two, 
flexible  longitudinal  steel  contact  strips,  supported  by  a  rigid 
member  near  the  trolley  wire,  but  insulated  from  the  latter, 
so  that  the  wheel  running  on  the  wire, — which  it  does  not 
leave, — touches  in  passing  one  or  both  of  the  contact  strips, 
which  are  electrically  connected.  These  strips  are  inclined 
outwardly  at  the  bottom,  flared  at  the  ends  to  receive  the  wheel 
easily,  and  mounted  by  flexible  phosphor  bronze  suspenders. 
The  deflection  of  the  strips,  however,  is  positively  limited  by 
steel  brackets  shown.  Each  strip  is  divided  Into  halves  elec- 
trically and  reunited  through  insulation  so  as  to  obtain  a  sense 


Figs.  616-617 


BLOCK    SIGNALS. 


95 


of  direction  without  the  use  of  moving  parts.  The  insulation 
between  the  contact  strips  and  trolley  wire  Is  through  hickory, 
Impregnated  under  vacuum  and  pressure  with  a  weather-proofing 
compound.  The  entire  contactor,  which  is  about  four  feet  Ions 
and  weighs  1  8  pounds,  is  hung  by  a  double-curve  suspension  at 
one  end,  and  clamped  to  the  wire  by  the  usual  trolley  ears. 
This  contactor  receives  the  various  size  wheels  without  shock, 
and  operates  the  signals  very  successfully  at  car  speeds  of 
55  miles  an  hour.  The  position  of  the  car  controller  handle 
does  not  in  any  way  affect  its  action. 

The  neutral  signal,  no  liyht  and  no  disk,  presumes  that  the 
block  is  clear,  and  gives  the  first  car  the  right-of-way  to  run 
under  the  contactor,  but  no  further. 

The  change  from  neutral  to  proceed,  a  white  lir/ht  and  a 
white  disk,  gives  the  first  car  the  right-of-way  to  continue 
through  the  block ;  but  a  neutral  signal  is  to  be  taken  as 
a  stop  signal  should  the  neutral  remain  after  the  car  has 


If  a  motorman  should  enter  a  block,  setting  the  signals,  ancH 
remain  there,  then  cars  for  any  reason  entering  and  backing 
from  either  end  in  any  manner,  whether  against  the  red  or 
white  signals,  will  not  disturb  the  signals  as  set  by  the  first 
car ;  and  only  when  all  the  cars  have  vacated  the  block  will  the 
signal  be  restored  to  neutral. 

The  trolley  contactors  have  a  sense  of  direction  so  as  to 
count  cars  Into  or  out  of  the  block,  according  to  the  end 
of  the  contactor  first  reached  by  the  trolley  wheel.  The  opera- 
tion is  perfectly  general  and  cars  may  enter  and  leave  by 
any  one  or  by  all  the  contactors. 

If  two  cars  from  opposite  ends  enter  at  exactly  the  same 
instant,  the  white  disks  will  not  remain  set,  but  will  disappear 
immediately,  leaving  neutral  signals  when  the  car  leaves  the 
contactor,  and  before  it  passes  the  box.  Each  car  should 
back  out  of  the  block,  and  the  one  having  the  superior  right 
should  go  forward,  setting  the  signals  against  the  other  car. 


Fig.  616.     Trolley  Contact  for  Nachod  Signal  System. 


passed  the  contactor.  It  indicates  that  the  stop  signal  has 
not  been  set  at  the  far  end  of  the  block. 

The  proceed  signal  notifies  the  second  and  following  cars 
that  the  block  is  occupied  by  cars  running  in  the  same  direc- 
tion; and  the  "blinking"  of  the  light,  as  the  second  and  fol- 
lowing cars  run  under  the  contactor,  gives  them  the  right-of- 
way  to  continue  through  the  block. 

The  stop  signal,  a  red  liyht  and  a  red  disk,  warns  the  motor- 
man  to  stop  and  remain  behind  the  contactor  so  long  as  it  is 
exhibited. 

The   motorman   must   not   pass    the   signal    box   to    enter   the 

I  lock  unless  the  white  light  and  white  disk  are  showing. 

A  car  must  not  follow  into  a  block  already  occupied  unless 
the  motorman  sees  the  white  light  blink  as  he  runs  under  the 
trolley  contactor. 

Motorman  must  not  allow  car  to  remain  standing  with  the 
trolley  on  the  overhead  crntactor. 


Fig.  617  shows  the  operation  of  the  electrical  system,  the 
apparatus  being  alike  at  both  stations,  and  in  the  normal 
position  with  no  car  in  the  block. 

The  directional  trolley  contactor  3A,  5A,  is  divided  Into 
halves,  reached  in  succession  by  the  trolley  wheel.  These  are 
interconnected  by  means  of  the  directional  magnets  E  and 
F,  so  that  a  car  entering  from  the  end  3A  will  close  the 
signal-setting  circuit  through  coil  A  in  the  relay,  and  hold  it 
closed  even  after  it  reaches  the  second  strip  5A.  But  should 
a  car  reach  the  end  5A  first,  then  the  circuit  will  be  closed 
through  the  clearing  magnet  C  in  the  relay,  and  held  closed 
by  the  directional  magnets  even  after  it  reaches  the  second 
strip  3A. 

The  circuits  through  the  directional  relay  are  described 
herewith  once  for  all,  and  not  each  time  they  are  mentioned. 
A  car  reaching  the  trolley  contactor  from  the  end  3A  diverts 
a  current  from  the  trolley  wire  4  through  3A,  3,  coil  E,  19, 


Fig.  617.     Diagram  of  Operation,   Nachod  Signal,        Type   "D." 


The  first  car  to  enter  the  block  in  passing  under  the  con- 
tactor sets  a  white  light  and  a  white  disk,  which  is  an  indi- 
cation that  the  red  light  and  red  disk  are  showing  at  the 
far  end.  Every  successive  car  following  in  an  occupied  block 
indicates  that  it  is  registered  by  extinguishing  the  white  light 
as  it  passes  under  the  contactor,  the  light  reappearing  the 
next  instant. 

Fifteen  cars  may  enter  the  block  in  succession  and  occupy 
It  at  once,  or  they  may  be  continually  entering  and  leaving, 
and  they  will  all  be  protected. 

If  the  motorman  should  accidentally  overrun  the  entering 
contactor  when  the  signal  shows  red  he  will  not  visibly  affect 
the  signals,  but  will  count  in  the  car  on  the  relay;  and  this 
change  will  be  canceled  when  he  backs  out  of  the  block  again 
under  either  contactor  to  wait. 

If  the  motorman  should  enter  a  clear  block,  under  either 
contactor,  setting  the  signals,  and  back  out  on  either  track  at 
the  same  end  of  th"e  block,  as  he  might  in  using  the  single 
track  at  a  Y  or  cross-over,  the  signals  will  be  automatically 
cleared  on  leaving. 


to  ground  2.  Coil  E  attracts  its  armature,  breaking  the  contact 
at  5  and  making  that  at  3,  so  that  when  the  car  reaches  the 
second  part  5A,  the  circuit  still  includes  coil  E,  being  made 
from  4,  5A,  3.  coil  E,  19,  2,  ground.  The  setting  magnet 
A  is  in  multiple  with  coil  E,  and  is,  therefore,  energized  with 
it.  In  an  exactly  similar  manner,  if  5A  is  reached  first,  then 
the  circuit  is  through  magnet  F,  wl.ich  will  attract  its  arma- 
ture and  maintain  current  in  it  even  when  the  car  has  reached 
3A.  The  clearing  magnet  C  in  the  main  relay,  being  in  multi- 
ple with  magnet  F,  is  therefore  continuously  energized  while 
the  car  is  on  the  contactor,  having  approached  it  from  the 
end  5A.  The  divided  contact  strips  and  the  directional  relay 
magnets  E  and  F  thus  act  selectively,  to  actuate  coils  A  or  C 
according  to  the  direction  of  the  car. 

In  the  clear  block,  both  ends  of  the  signal  wire  are  grounded 
through  the  circuit,  1,  9,  8,  7,  2,  ground,  including  coil  H 
and  the  red  lamp. 

A  car  entering  from  the  left  temporarily  connects  contact 
strip  3A  of  trolley  contactor  with  trolley  wire,  forming  a 
circuit,  4,  3A,  3,  10,  11,  17,  2,  ground,  passing  through 


BLOCK    SIGNALS. 


Fig.  618 


toll  A.  This  Impulse  of  current  in  A  moves  its  plunger  to  re- 
volve the  two-way  switch,  transferring  the  end  of  the  signal 
wire  9  from  contact  8  to  contact  13.  Current  then  flows  from 
trolley  wire,  4,  13,  9,  1,  signal  wire  to  other  relay  to  ground 
as  described.  When  the  car  leaves  the  contactor,  plunger  A 
drops  back  into  the  position  shown,  while  plunger  D  remains 
in  the  retracted  position  on  account  of  the  current  in  coil  D. 
The  white  light  now  burns,  since  it  is  in  shunt  across  D  by 
the  path  4,  W,  6,  14,  13;  and  the  red  light  also  burns  in  the 
other  relay  because  of  the  current  in  the  signal  wire.  The 
retracted  position  of  plunger  D  in  the  one  relay,  and  that  of 
plunger  H  in  the  other,  permit  the  display  of  the  white  and 
red  disks,  respectively.  So  long  as  the  red  signal  continues, 
the  circuit  of  magnet  A  is  held  open  at  3,  10,  preventing 
change  in  the  left  relay  by  cars  entering  at  contactor  3A 
against  the  red  signal.  The  effect  of  successive  entering  cars 
is  to  revolve  the  switch  so  that  the  contacts  overlap  further, 
but  not  to  cause  any  electrical  change  in  the  signal  circuit, 
ercept  that  each  entering  car  actuates  magnet  A  so  as  to 
break  the  lamp  circuit  at  switch  13,  14,  causing  the  white 
light  to  blink. 

When  the  car  leaves  the  block  at  the  right  end  it  runs 
under  contactor  5A,  completing  the  circuit,  4,  5A,  5,  12,  18,  2, 
ground.  The  plunger  of  magnet  C  opens  the  signal  line  wire 
circuit  at  1,  9,  breaking  the  circuit  of  magnet  D  in  the  entering 
relay.  The  plunger  of  D  is  restored  to  its  original  position, 
revolving  the  switch  in  the  reverse  direction,  one  notch  at  a 
time  for  each  leaving  car.  When  there  have  been  as  many 
breaks  of  current  in  coil  D  as  impulses  of  current  in  A,  the 


Magnet  C  is  provided  with  a  dashpot  to  retard  its  return 
motion  and  allow  magnet  D  to  act  during  the  breaking  of  its 
circuit. 


Fig.  618.     Nachod  Signal  Relay  Unit. 

revolving  switch  will  be  in  its  original  position,  and  the  signals 
will  be  cleared. 

If  the  car  enters  the  block  by  contactor  3A,  5A,  it  will  ener- 
gize magnet  A  and  set  the  signals;  while  if  it  backs  out  under 
the  same  contactor,  it  will  energize  magnet  C  to  clear  them. 
If  a  car  should  accidentally  overrun  the  contactor  against  a 
red  signal,  then  current  would  flow  through  signal  wire  6A 
to  the  distant  relay,  and  through  setting  coil  A  there,  by 
means  of  the  color  disk  switches,  one  of  which  will  be  closed 
in  each  signal  box.  But  there  would  be  no  effect  on  the  signal 
showing  reel,  since  the  circuit  of  the  setting  magnet  A  would 
bo  held  open  at  contacts  10,  3,  as  stated.  The  second  signal 
wire  6A  is,  therefore,  a  means  for  enabling  a  car  running 
against  the  red  signal  to  count  in  on  the  distant  relay,  that 
it  may  count  out  again  in  backing.  It  is  in  use  only  in  such 
rare  instances. 

The  function  of  magnet  N  is  to  prevent  change  of  signals 
should  the  power  fail  with  cars  on  the  block.  It  is  per- 
manently connected  across  the  line  in  series  with  a  high  re- 
sistance, 4,  15,  16,  2.  Should  the  current  fail  while  the 
plunger  of  D  is  drawn  up,  the  plunger  of  N  will  catch  that 
of  D  to  prevent  it  from  rotating  the  ratchet. 

All  the  magnets  are  arranged  so  that  after  the  stroke  is 
partly  completed,  the  current  in  the  coil  is  reduced  either  by 
insertion  of  resistance  or  by  shunting  current  around  them. 
For  instance,  betore  the  plunger  of  C  moves,  the  current  passes 
through  the  resistance  18,  2  only,  but  after  it  has  moved  it 
passes  through  the  additional  length  12-18  and  is,  therefore, 
reduced  in  strength.  By  this  means  the  magnet  is  operative 
over  a  very  large  voltage  range;  and  is  also  protected  from 
burn-out  should  the  car  remain  under  the  trolley  contactor. 


THE   UNITED  STATES   ELECTRIC    BLOCK    SIGNAL   SYSTEM. 

In  the  signaling  system  made  by  the  United  States  Electric 
Signal  Co.  the  apparatus  contained  in  a  block  of  signals  con- 
sists of  two  signal  boxes,  four  disk  attachments  and  four  oper- 
ating trolley  switches.  The  boxes  contain,  for  the  home  sig- 
nals, both  lights  and  disks,  the  light  being  placed  in  the  disk 
case  and  being  visible  through  the  glass  enclosing  the  same, 
therefore  making  a  complete  and  independent  visual  signal  .in 
itself  as  well  as  to  illuminate  the  disks  in  the  night-time,  as 
shown  in  Fig.  C23. 

Two  sets  of  home  signals  are  used  at  each  station ;  one  on 
each  side  of  the  main  box,  and  alternate  successively  for  each 
car  as  it  enters  the  block.  That  is,  a  car  upon  entering  the 
block  will  display  one  set  of  the  home  signals  (both  light  and 
disk)  either  on  the  right  or  left.  Upon  the  second  car  enter- 
ing, another  set  (both  light  and  disk)  will  be  displayed  on  the 
opposite  side  of  the  box  and  the  ones  that  were  formerly 
displayed  will  be  restored. 

At  the  distant  end  of  the  block  a  red  light  only  is  used 
for  a  danger  signal.  A  car  upon  leaving  the  block  at  the 
distant  signal  will  maintain  the  red  signal  set  and  momentarily 
display  one  of  the  home  signals  at  that  end.  During  this 
operation  the  home  signal  at  the  entrance  end  of  the  block 
will  also  be  momentarily  restored  and  the  red  signal  will  be 
momentarily  displayed. 

Four  operating  trolley  switches  are  used  and  are  located  over 
the  double  track  some  distance  from  the  junction,  so  that  n 
car  will  be  able  to  come  to  a  stop  before  reaching  said  junc- 
tion if  it  should  be  blocked  by  the  red  signal  upon  entering 
the  block.  The  setting  switches  are  provided  with  setting 
connections  only.  Therefore,  if  a  car  should  unavoidably  pass 
the  same  after  the  signal  had  been  set  from  the  distant  end 
of  the  block,  it  can  move  back  and  get  into  position  to  proceed 
and  set  the  signal  after  awaiting  the  passing  of  the  coming 
car  without  danger  of  turning  off  or  restoring  the  set  signal 
in  so  doing.  The  restoring  switches  are  placed  on  the  opposite 
track  and  are  provided  with  restoring  connections  only  and 
are  only  operative  by  cars  leaving  the  block. 

The  signal  relay  consists  of  a  step  wheel,  locking  devices 
and  four  operating  magnets  and  switches  governed  by  their 
armature,  the  two  forward  magnets  operating  to  set  and  re- 
store the  signal, — the  one  on  the  right  to  set,  and  the  one 
on  the  left  to  restore. 

The  front  and  right-hand  magnet  is  charged  from  the  over- 
head trolley  switch  directly  to  ground  through  a  resistance  of 
its  own  as  the  car  enters  the  block,  which  serves  to  turn  the 
step  wheel  one  step  in  the  accumulative  or  setting  direction. 
This  operation  causes  the  switch  lever  to  move  from  the 
ground  contacts  on  the  right  to  the  feed  contacts  on  the  left. 

The  distant  end  of  the  circuit  being  in  connection  with  the 
ground  by  means  of  the  springs  on  the  right  at  that  end,  a 
circuit  is  thus  established  and  the  signals  are  electrically  dis- 
played. When  the  signals  are  thus  displayed  one  set  of  the 
home  signals  on  the  side  of  the  home  box  is  displayed. 

The  second  car  upon  entering  the  bloc*k  and  during  the  time 
the  first  car  is  yet  on  the  block  will  display  the  set  of  signals 
on  the  opposite  side  of  the  box  and  restore  the  set  that  were 
formerly  displayed  and  thus  alternate  as  heretofore  mentioned 

At  the  distant  end,  the  red  light  in  the  upper  part  of  box 
proper  will  remain  constantly  displayed  during  the  operations. 
When  the  signals  are  thus  set  the  current  will  flow  through 
the  home  box  through  the  home  signals  and  the  rear  left-hand 
magnet  of  the  relay  at  said  home  box. 

This  latter  magnet  at  the  home  box  operates  the  lever  which 
serves  to  lock  the  restoring  armature  lever  by  co-operating 
with  a  pin  extending  through  the  same  so  that  the  restoring 
magnet  cannot  operate  to  restore  the  signals  until  the  signaling 
circuit  is  opened.  This  circuit  can  only  be  opened  at  the  trolley 
switch  and  by  a  car  passing  off  of  the  block.  Therefore,  if  the 
line  should  become  charged  by  the  crossing  of  the  wires  between 
stations,  the  signals  could  not  be  restored  on  account  of  this 
lock. 

At  the  distant  signal  box  the  signaling  current  will  flow 
through  the  red  lamp  and  the  restoring  magnet. 

The  pawl  or  operating  lever  carried  by  the  armature  of 
this  restoring  magnet  serves  as  a  locking  device  to  prevent  the 
step  wheel  being  turned  if  a  car  should  by  accident  run  past 
the  setting  switch,  going  on  to  the  block  after  the  signals  had 
been  set. 

By  a  peculiar  arrangement  of  co-operating  pins  in  the  pe- 
riphery of  the  step  wheel  and  the  side  of  the  restoring  pawl, 
the  pawl  is  held  into  engagement  with  the  step  wheel  after 
the  signal  has  been  fully  restored,  thus  maintaining  its  restored 


Figs.  619-622 


BLOCK    SIGNALS. 


97 


position  and  at  the  same  time  mechanically  holding  the  arma- 
ture up  to  the  poles  of  the  restoring  magnet. 

The  signals  are  restored  by  a  car  leaving  the  block  by  means 
of  the  overhead  trolley  switch,  located  as  heretofore  described, 
from  which  the  current  will  flow  to  the  rear  right-hand  mag- 
net of  the  distant  box  of  the  danger  or  red  set  signal,  thence 
into  the  unlocking  circuit  and  to  the  home  box  which  has 
previously  been  set  by  cars  entering  the  block,  thence  through 
the  restoring  magnet  and  through  the  red  signals  to  ground, 


step  wheel  being  mounted  loosely  on  the  same,  so  that  It  will 
revolve  without  rotating  the  shaft  and  operating  the  alternat- 
ing lever  when  being  rotated  in  the  direction  of  restoration  by 
a  car  leaving  the  block. 

However,  by  means  of  a  ratchet  wheel,  which  is  mounted 
rigidly  to  the  shaft  with  a  pawl  securely  attached  to  the 
step  wheel  adapted  to  engage  the  ratchet  wheel,  the  shaft  and 
the  notch  wheel  that  serves  to  alternate  the  signals  will  rotate 
when  operated  by  a  car  entering  the  block. 


Fig.  610.     Signal  Relay  Type  Gi. 


Fig.  620. 


Type  K  Signal  Mechanism.     Open. 
States  Electric  Signal  Company. 


United 


Fig.   621.     Type    d    Signal    Mechanism.      Open. 

thereby  charging  the  first  magnet  mentioned  at  the  distant  or 
red  set  signal. 

This  will  cause  the  contact  lever  carried  by  its  armature  to 
move  over  from  right  to  left,  opening  the  main  signaling  cir- 
cuit at  the  spring  contacts  on  the  right  at  the  distant  box. 

The  locking  magnet  on  the  rear  left  of  the  home  box  will 
then  be  discharged,  allowing  the  locking  devices  at  the  home 
box  to  operate  to  unlock  the  restoring  magnet  at  the  home 
box  and  cause  it  to  operate  to  rotate  the  wheel  back  toward  the 
point  of  restoration  one  tooth,  as  represented  by  the  out-bound 
car. 

The  circuit  opening  magnet  at  the  distant  box  will  again 
close  the  signaling  circuit,  and  if  there  are  yet  cars  in  the 
block,  charge  the  left-hand  rear  magnet  at  the  home  box, 
thereby  again  locking  the  armature  of  the  restoring  magnet  at 
the  home  box. 

The  alternating  lever  is  operated  by  means  of  a  notch  wheel, 
which  is  mounted  rigidly  on  the  shaft  of  the  step  wheel,  the 


Fig.  622.     Signal  Relay.     Type  K. 

The  main  switch  lever  that  serves  to  set  and  restore  the 
signals  to  normal  is  operated  by  a  cam  wheel  rigidly  mounted 
directly  to  the  step  wheel. 

With  this  understanding,  it  will  be  seen  that  the  main  switch 
lever  does  not  operate  except  for  the  initial  setting  of  the 
signals  by  the  first  car  and  the  final  restoration  of  the  same 
by  the  last  car. 

This  device  just  explained  prevents  the  signals  alternating 
when  the  step  wheel  is  rotated  in  the  direction  of  restoration 
by  a  car  leaving  the*  block,  thereby  anticipating  any  possible 
danger  of  confliction  of  display  by  cars  entering  and  leaving 
the  block  at  the  same  time. 

Fig.  624  shows  the  standard  signal  box  equipped  with  disks 
in  addition  to  the  colored  lights.  These  disks  operate  inde- 
pendently of  the  lights  and  are  located  on  opposite  sides  of  the 
box.  The  lamps  operate  in  unison  with  the  disks. 

Figs.  619  and  622  show  the  relay.  It  is  the  mechanism  which, 
in  conjunction  with  a  trolley  switch,  operates  the  lights  and 


BLOCK    SIGNALS. 


Figs.  623-625 


disks.  There  is  a  small  mechanical  lock  in  the  mechanism  which 
holds  the  lever  in  a  closed  position  until  it  is  unlocked  by  a  car 
leaving  the  block.  The  disks  which  furnish  the  indications  in 
addition  to  the  lights  are  housed  in  separate  castings,  which 
are  fastened  to  the  main  signal  box.  The  disks  are  eight  inches 
in  diameter  and  are  pivoted  horizontally  between  two  glass 
windows.  They  are  made  of  sheet  metal,  painted  and  var- 
nished. One  disk  is  red  and  the  other  is  green  and  white. 
The  disks  are  operated  by  a  large  magnet  placed  in  the  lower 
part  of  a  housing  and  there  is  no  connection  between  them  and 
the  main  signal  box.  They  work  independently  of  the  lights. 
Lenses  five  inches  in  diameter  are  used  in  the  lights. 

The   actual    location    of    the   wires,    contacts    and   fuses   con- 
nected with  the  United  States  system  is  shown  in  Fig.  626  and 
the  path  of  the  current  through  the  magnets  and  signals  and 
the  manner  in  which  the   signal   is  set  and   released  are  indi- 
cated.    With   the   signal   in   its  normal   position   the  ^mechanism 
is    in    the   position    shown    in    the    figure    and 
there  is  no  current  flowing  through  the  system. 
When  the  car  represented  by  the  wheel  entered 
the  block  it  closed   the  right-hand  contacts  of 
trolley    switch    for    an    instant,    allowing    the 
current  to  flow  over  the  circuit  represented  by 
heavy  dashes,  through  magnet  A  and  over  line 
wire  No.    3,    through  the   other   signal,   to   the 
ground,  as  shown  by  the  heavy  full  line. 

Magnet  A,  upon  being  energized,  throws 
over  its  contact  lever,  disconnecting  the  ground 
at  this,  the  setting  end,  and  cutting  in  a  per- 
manent feed  from  the  trolley  wire  to  take  the 


of  cars  in  a  block  at  a  time  by  means  of  a  step  wheel,  which 
is  rotated  in  one  direction  by  cars  entering  the  block,  and  in 
the  opposite  direction  by  cars  leaving  the  block.  This  is  ac- 
complished by  means  of  mnguets  having  armatures  carrying 
pawls  that  engage  the  teeth  or  pins  in  the  rim  of  the  step 
wheel.  The  magnet  (with  its  pawl)  on  the  right-hand  side  is  the 
one  that  operates  to  turn  the  wheel  in  the  setting  direction, 
and  the  one  on  the  left  is  the  one  that  turns  it  in  the  direc- 


Fig   623.     Type  K  Signal  Box. 


place  of  the  switch  contact,  which  opens  immediately  after 
the  car  passes.  This  permanent  feed  also  throws  the  green 
lamp  and  disk  Into  the  signaling  circuit  and  it  is  their  ap- 
pearance which  tells  that  the  red  signal  is  displayed  at  the 
opposite  end.  The  other  set  of  contacts  closed  by  this  magnet 
completes  a  circuit  which  starts  in  the  outside  contacts  of  both 
trolley  switches.  It  will  be  seen,  upon  looking  at  the  diagram, 
that  the  signaling  circuit  leads  through  magnet  B'  at  the  other 
end,  opening  a  pair  of  contacts  known  as  the  non-interference 
device.  These  contacts  open  the  setting  circuit  from  the 
trolley  switch  and  prevent  a  car  trying  to  enter  from  the  op- 
posite end,  locking  up  the  lever  to  magnet  A',  which  would 
connect  both  ends  of  the  signaling  circuit  to  the  trolley  wire, 
making  a  dead  signal  until  some  car  passed  out  of  the  block. 
The  circuit  indicated  by  light  dashes  is  known  as  the  releas- 
ing circuit.  When  the  car  leaves  the  block,  going  in  the 
direction  shown  by  the  wheel,  it  closes  the  right-hand  contacts 
in  the  right-hand  switch,  thus  allowing  current  to  flow  through 
magnet  C',  which  breaks  the  main  signaling  circuit,  and  also 
through  magnet  B,  which  unlocks  the  lever  of  magnet  A.  The 
magnet  A,  now  being  de-energized  and  the  lock  open,  allows 
the  lever  to  fall  back  and  the  system  is  in  its  normal  position 
of  no  car  in  the  block. 

In  proceeding  with  this  Illustration  it  will  be  necessary  to 
understand,  in  a  general  way,  the  mechanical  operation  of  this 
character  of  signal.  This  signal  provides  for  a  multiplicity 


Fig.    624.     Type    d    Signal    Box. 


3PRJNG   CONTACTS 
UNDER    RELAY 


|2  |<3  |3  |4  [5 

Fig.  625.     Wiring  Diagram  for  Type   K  Mechanism. 


tion  to  restore.  It  will  be  understood  that  the  step  wheel  will 
be  turned  one  pin  for  each  car  as  it  enters  the  block,  and  it 
will  be  turned  back  in  the  opposite  direction  one  pin  for 
each  car  as  It  leaves  the  block ;  and  when  as  many  cars 
have  passed  off  the  block  as  haye  passed  on  to  it,  the  wheel 
will  be  brought  to  a  normal  position  and  the  signal  will  be 
restored  to  normal. 


Figs.  626-627 


BLOCK    SIGNALS. 


99 


In  Fig.  626,  when  the  trolley  wheel  passes  the  switch  going  on 
to  the  block,  it  closes  the  circuit  at  the  point  marked  "trolley 
switch."  The  current  will  flow  through  the  heavy  dotted  line 
to  the  No.  4  terminal  in  the  box,  through  the  fuse  and  th<> 
front  right-hand  magnet  to  the  resistance,  into  the  ground 
wire  and  to  the  ground.  This  will  cause  the  setting  magnet 
to  be  energized  and  will  operate  to  turn  the  step  wheel  one 
pin  in  the  setting  direction.  This  will  cause  the  main  contact 
lever,  which  is  the  front  one,  to  move  over  from  Its  normal 
position  on  the  right  to  the  contact  spring  on  the  left.  The 
current  will  then  flow  from  the  trolley  wire,  over  the  heavy 
full  line  to  the  No.  1  terminal  through  the  fuse,  thence  to 
the  pick-up  magnet  to  the  lamp  on  the  right-hand  side  of  the 
box,  thence  to  the  semaphore  to  the  spring  contacts  on  the 
right,  crossing  over  to  the  spring  contacts  on  the  left  back  to 
spring  contacts  on  the  rear  right ;  thence  to  the  locking  mag- 
net leaving  the  home  box  at  the  No.  3  terminal,  and  through 


Fig.  626.     United  States  Block  Signal  System, 
with   Car  in   Block. 


Circuits 


the  wire  of  the  signaling  circuit  to  the  No.  3  terminal  at  the 
distant  box;  thence  to  the  rear  left-hand  magnet  to  spring  con- 
tacts on  the  rear  right  to  spring  contacts  on  the  front  right : 
thence  to  the  restoring  magnet  on  the  left  to  the  pick-up 
magnet  on  the  right,  and  to  red  lamp  at  the  top  of  the  box, 
through  the  resistance  to  ground.  As  indicated,  this  will 
cause  the  top  lamp  in  the  right-hand  disk  box  and  the  disk 
also  to  be  displayed  at  the  home  box,  and  the  front  lamp 
in  the  upper  window  of  the  distant  box  to  be  displayed. 
Upon  a  second  car  entering  the  block,  the  alternating  switch, 
which  is  the  middle  one  of  the  relay,  will  move  over  to  the 
opposite  side  of  the  box,  opening  the  springs  on  the  right 
and  closing  those  on  the  left.  This  will  cause  the  current 
to  flow  through  the  lamp  and  disk  on  the  left-hand  side 
ef  the  box,  thus  displaying  another  set  of  signals  at  the  homo 
box.  These  signals  will  alternate  successively  as  cars  enter 
the  block  for  as  many  as  15  cars,  the  distant  red  signal  re- 
maining constantly  displayed  during  these  operations. 

When  a  car  leaves  the  block,  the  contacts  will  be  closed  ac 
the  restoring  side  of  the  trolley  switch,  and  the  current  will 
flow  over  the  wire,  represented  by  the  light  full  line,  leading 
to  the  No.  5  terminal  at  the  extreme  right  of  the  box,  to  the 
magnet  at  the  rear  right-hand  side  of  relay  into  the  No.  2  cir- 
cuit. The  current  will  then  flow  over  the  restoring  circuit  to  the 
home  box,  which  has  been  set  by  the  cars  entering  the  block, 
will  enter  the  same  at  No.  2  terminal  through  the  fuse  to 
the  front  contact  lever,  and  through  it  to  the  front  left- 
hand  magnet,  thence  to  ground  through  the  red  signal,  mo- 
mentarily energizing  the  front  left-hand  restoring  magnet  at 
the  home  box  and  the  rear  right-hand  magnet  at  the  distant  box. 
This  will  cause  the  contact  lever  at  the  rear  of  relay  to  move 
over  to  the  left  and  "open  the  signaling  circuit,  at  the  same 
time  closing,  by  means  of  the  contact  springs,  a  derived  circuit 
to  prolong  the  charged  moment  of  the  restoring  magnet. 


KINSMAN   BLOCK    SYSTEM. 

A  system  of  automatic  block  signaling  for  electric  railways 
operated  by  direct  current  and  controlled  by  track  circuits 
has  been  designed  and  installed  by  the  Kinsman  Block  System 
Co.  The  indications  are  given  by  semaphore  and  light  signals. 
The  track  circuits  consist  of  two  insulated  rail  sections  at 
each  end  of  the  block,  a  relayed  rail  being  used  as  a  jumper 
around  the  insulated  section,  for  the  return  traction  current. 
There  are  two  track  relays,  one  called  the  setting  and  the 
other  the  releasing  relay  operated  by  two  cells  of  primary 
battery.  The  controller  is  a  step-by-step  mechanism  designed 
to  allow  cars  running  in  the  same  direction  to  enter  a  block. 
Each  car  entering  the  block  sets  the  controller  one  step 
forward,  and  each  car  leaving  the  block  sets  it  one  step 
backward  until  the  last  car  leaves,  which  restores  the  con- 
troller to  normal. 

Cars  going  in  the  same  direction  may  thus  be  continually 
entering  and  leaving  the  block  under  signal  protection.  Fig. 
627  is  the  front  view  of  the  controller  with  the  cam  in  the  nor- 
mal or  clear  position.  This  shows  the  switch,  which  governs 
the  signal  movements  in  the  normal  position.  When  the  front 
ratchet,  which  is  controlled  by  the  setting  magnet,  Is  operated, 
this  cam  turns  clockwise,  and  as  it  does  so  it  forces  the  pin, 
shown  on  the  switch,  down,  so  that  the  switch  is  thrown.  A 
second,  third,  or  fourth  operation  of  the  setting  ratchets  would 
operate  this  cam  in  a  clockwise  direction,  but  would  not  affect 
the  switch.  The  cam  simply  revolves  the  angular  distance 
of  one  tooth  as  each  car  enters  the  block,  thus  actually  count- 
ing, or  recording,  the  number  of  cars.  As  each  car  passes  out 


Fig.  627.     Semaphore  Signal  Mechanism. 
Block  System  Company. 


Kinsman 


of  the  block  the  release  magnets  on  the  machine  are  energized, 
the  release  ratchet  wheel  is  operated,  and  the  cam  is  operated 
counter  clockwise,  moving  it  back  towards  its  normal  position. 
There  is  no  movement  of  the  switch  until  the  last  car  passes 
out  of  the  block  when  the  cam  operates  the  switch.  When 
the  last  movement  of  the  cam  is  made,  the  pin  on  the  switch 
is  forced  up  into  the  slot  in  the  cam.  This  rocking  move  of 
the  switch  is  called  a  "Geneva"  movement.  There  is  a  brass 
rod  on  each  side  of  the  machine  upon  which  are  wound  steel 
springs.  Each  of  these  springs  forces  down  one  end  of  the  lever. 
The  other  end  of  this  lever  is  lifted  up  and  engages  the  lower 
arm  of  the  pawl,  which  is  connected  to  the  armature  of  the 
magnet.  This  lever,  by  virtue  of  the  spring  tension,  lifts  up 
the  pawl  when  the  magnet  is  released,  and  also  lifts  up  the 
armature  of  the  magnet.  As  the  pawl  is  lifted  up  it  is  also 
forced  against  the  ratchet  wheel,  so  the  pawl  drops  into  the 


IOO 


BLOCK    SIGNALS. 


Figs.  628-6a< 


notch  of  the  ratchet  wheel.  There  is  a  small  dog  at  the  top  of 
the  controller  which  is  used  as  a  detent.  This  detent  simply 
prevents  the  ratchet  wheel  from  turning  in  the  opposite  direc- 
tion when  the  operating  pawl  is  being  lifted  up  after  it  has 
completed  a  stroke.  When  a  car  passes  over  the  releasing  sec- 
tion, the  releasing  magnet  becomes  energized  and  the  release 
ratchet  operates,  revolving  in  the  opposite  direction.  This  will 


screw.  This  cam  operates  the  electric  switch.  The  shaft  also 
has  the  casting,  which  carries  the  aluminum  beveled  gear.  This 
casting  is  keyed  to  the  shaft.  There  are  also  on  the  shaft  the 
armatures  of  the  two  pairs  of  magnets ;  these  operate  loosely 
on  the  shaft,  and  are  not  rigidly  connected  with  it.  There  are 
also  the  two  main  ratchet  wheels,  which  likewise  operate  loosely 
on  the  shaft.  The  two  brass  beveled  gears  are  riveted  and 


Fig.  628.     Arrangement  of  Signals  and  InsuMted  Sections  at  Double  End  Sidings.     Kinsman  Block  System  Co. 


set  the  swinging  contacts  at  normal.  If  more  than  one  car 
passes  through  the  block  in  the  same  direction,  each  car,  as  it 
passes  over  the  setting  section,  will  cause  the  setting  ratchet 
to  operate  and  move  the  cam  one  step,  and  as  each  car  passes 
over  the  releasing  section  at  the  far  end  of  the  block,  it  will 
cause  the  cam  to  move  back  one  step  toward  putting  the  swing- 
ing contact  again  to  normal.  For  example,  if  five  cars  were 
moving  in  the  same  direction  through  a  block,  the  whole  five 
cars  would  have  to  pass  through  the  block  before  the  signals 
would  clear  up,  and  should  any  of  these  cars  have  occasion  to 


Fig.  629.     Semaphore  Signal.    Kinsman  Block  System 
Company. 

back  up  and  leave  the  block  at  the  end  they  entered,  the  signal 
would  clear  up  just  as  if  they  had  all  gone  through  the  block. 
Two  resistance  tubes,  placed  between  magnets,  are  wound  with 
fine  wire  and  inserted  in  place  the  same  as  a  fuse  is  mounted 
between  metal  clips.  These  resistances  are  connected  to  the 
550-volt  circuit  on  one  end  ;  the  other  end  of  the  front  resist- 
ance is  connected  to  the  setting  magnets,  which  are  in  series. 
The  other  end  of  the  resistance  in  the  back  is  connected  to  the 


soldered  to  the  ratchet  wheels,  and  they  also  are  loose  on  the 
shaft.  The  armatures  have  a  fixed  stud  in  their  upper  ends, 
which  carries  the  pawls  that  operate  the  ratchets.  The  pawls 
are  free  to  turn  on  this  stud.  When  the  right-hand  ratchet 
wheel  is  operated  by  the  pawl  attached  to  the  right-hand 
magnet  (this  is  the  setting  magnet)  it  is  turned  in  the  right- 
hand,  or  clockwise,  direction  (when  viewing  the  machine  from 
the  end  which  has  the  cam),  the  release  ratchet  wheel  is  oper- 
ated in  the  opposite  direction,  so  that  if  both  of  these  wheels 
were  to  operate  at  the  same  time  the  aluminum  gear  would 
simply  be  revolved  on  its  axis  without  causing  any  movement 
of  the  shaft ;  but  should  the  setting  magnet  operate,  while  the 
release  magnet  is  not  affected,  the  ratchet  wheel,  by  means 
of  the  gear  wheels,  would  turn  the  shaft  and  cam  in  a  clockwise 
direction.  When  this  movement  is  made  the  aluminum  gear 
is  turned  by  the  setting  side  of  the  machine  (the  release  Bide 
being  stationary).  It  is  clear  that  the  only  motion  transmitted 
to  the  shaft  is  the  difference  of  the  motion  of  both  setting  and 
release  ratchet  wheels.  The  only  time  that  both  these  wheels 
would  be  operated  at  the  same  instant  is  when  the  car  is 
entering  the  block  at  the  same  time  that  a  car  is  passing 
out  of  the  block  at  the  opposite  end. 

In  Fig.  631  the  semaphore  blade  and  spectacle  are  controlled 
by  two  magnets,  "A"  and  "B."  Magnet  "A"  is  the  operating 
magnet,  which,  when  energized,  operates  the  signal  to  the  "clear" 
position  and  holds  it  in  that  position  normally.  When  magnet 
"A"  is  de-energized  the  signal  operates  by  gravity  to  the  "stop" 
position  unless  the  slot  magnet  "B"  is  energized,  in  which  case 
the  semaphore  is  stopped  and  held  in  the  45  deg.  position. 
There  are  two  pairs  of  contacts,  "E"  and  "G,"  which  are  closed 
when  the  signal  is  in  the  vertical  or  45  deg.  position.  These 
contacts  are  opened  when  the  signal  is  in  the  horizontal  or 
"stop"  position. 

The  signal  mechanism,  as  described,  is  operated  by  circuits 
which  are  made  up  through  the  controller.  The  controller  Is 
operated  by  two  magnets,  "S"  and  "R."  Magnet  "S"  is  energized 
each  time  a  car  passes  over  the  insulated  sections  of  track 
while  entering  the  block.  Magnet  "R"  is  operated  each  time  a 
car  passes  over  the  insulated  sections  while  leaving  the  block. 
The  controller  is  operated  by  a  track  circuit  which  consists  of 
two  relays,  "S"  and  "R,"  which  are  operated  by  current  from 
two  cells  of  battery.  These  relays  are  connected  to  short  ad- 
jacent sections  of  track,  "S"  and  "R."  When  a  car  approaches 
the  signal  while  entering  the  block  it  runs  on  the  track  section 
"S,"  which  completes  a  circuit  operating  the  setting  relay  "S." 
The  operation  of  this  relay  opens  a  circuit  to  the  release  relay 
"R"  and  connects  the  insulated  sections  "S"  and  "R"  so  that 
the  setting  relay  remains  energized  until  the  last  wheels  of  the 
car  or  train  have  passed!  off  the  section  "R."  As  a  car  passes 


Fig.   630.     Arrangement   of   Signals   and   Insulated   Sections  on  Double  Track. 


release  magnets,  which  are  also  in  series.  The  other  terminal 
of  the  setting  magnet  is  carried  to  the  front  contacts  of  the 
setting  relay,  whereas  the  extra  terminal  of  the  release  magnet 
IB  carried  to  the  front  contacts  of  the  release  relay.  There 
is  a  shaft  that  extends  through  the  machine,  and  on  the  right- 
hand  end  there  is  a  cam  securely  fastened  to  it  with  a  set 


over  the  insulated  sections  when  leaving  the  block  the  release 
relay  is  energized.  This  opens  the  circuit  of  the  setting  relay 
and  connects  the  sections  "S"  and  "R"  so  that  the  release  relay 
remains  energized  until  the  car  has  passed  over  both  sections. 
The  operation  of  the  setting  relay  operates  the  setting  magnet 
on  the  controller,  which  causes  the  controller  shaft  and  cam  to 


Figs.  631 


BLOCK    SIGNALS. 


101 


operate  one  step  in  a  clockwise  direction  from  its  normal  posi- 
tion and  each  operation  of  the  release  relay  operates  the  release 
magnet  on  the  controller,  operating  the  shaft  and  cam  one  step 
toward  the  normal  position. 

The  first  operation  of  the  setting  magnet  turns  the  shaft  and 
cam  one  step  and  the  switch  of  the  controller  is  thrown  to<  the 
reverse  position  from  that  shown  on  the  drawing.  Each  suc- 
ceeding operation  of  the  setting  magnet  causes  the  shaft  and 
cam  to  turn  one  step,  but  does  not  affect  the  switch,  Each 
operation  of  the  release  magnet  on  the  controller  causes  the 
shaft  and  cam  to  operate  one  step  toward  the  normal  position, 
but  does  not  affect  the  switch  until  the  last  step  is  made  when 
the  cam  assumes  its  normal  position  and  throws  the  switch  to 
normal,  as  shown  on  the  drawing.  Whenever  the  setting 
magnet  of  the  controller  is  energized  the  contacts  "F"  are  closed. 
Whenever  the  release  magnet  of  the  controller  is  energized  the 
contacts  "H"  are  closed.  There  are  two  line  relays  "L,"  one 
in  each  signal  and  these  relays  are  normally  energized. 

There  are  three  circuits  through  magnet  "A"  :  First — This 
m.-ignet  is  normally  energized  and  holds  the  signal  in  the 
"clear"  position  by  current  which  flows  from  the  feed  wire  at 
station  "A,"  through  magnet  "A,"  through  the  front  contacts 


Current  flows  from  the  feed  wire,  through  a  resistance, 
through  the  controller  switch  and  contacts  "RR"  and  through 
the  slot  magnet  "B"  to  ground.  This  causes  the  slot  magnet 
to  operate  so  that  the  signal  is  stopped  in  its  downward  move- 
ment and  held  in  the  45  deg.  position.  This  operation  of  the 
signal  from  "clear"  to  "caution"  is  authority  for  the  car  to 
proceed  through  the  block. 

As  each  succeeding  car  enters  the  block  it  operates  the  set- 
ting relay  and  the  setting  magnet  on  the  controller  and  closes 
contact  "F."  The  closing  of  contact  "F"  completes  the  third 
circuit  just  described  above  through  magnet  "A"  and  causes 
the  signal  to  operate  from  the  "caution"  to  the  "clear"  position 
as  the  car  runs  on  the  insulated  sections.  As  the  car  runs  off 
the  sections  the  contact  "F"  opens  and  allows  the  signal  to 
operate  by  gravity  from  the  "clear"  back  to  the  "caution1' 
position.  This  operation  of  the  signal  from  "caution"  to  "clear" 
and  back  to  "caution"  again  Is  the  authority  for  each  suc- 
ceeding car  to  proceed  through  the  block. 

There  are  three  circuits  through  the  line  relays  "L"  :  First- 
Current  flows  from  the  feed  wire  at  station  "A"  through  a 
resistance,  through  the  controller  switch,  through  contact 
"RN"  on  the  controller,  through  contact  "E"  in  the  signal, 


Fig.   631.     Controlling   Circuit   tor    Kinsman    Block   System  on  Single  Track  Electric  Railways. 


of  the  line  relay  "L"  at  station  "A,"  through  the  controller 
switch,  through  contact  "LN"  at  station  "A,"  over  line  wire  1, 
through  contact  "LN"  on  the  controller  at  station  "B,"  through 
tho  controller  switch,  through  the  front  contact  of  the  lino 
relay  "L,"  through  magnet  "A"  to  ground.  As  a  car  enters  the 
block  at  station  "A"  the  controller  in  that  signal  operates  and 
the  switch  is  thrown  to  the  reverse  position.  The  circuit  just 
described  is  opened  at  the  switch  contact  "LN,"  de-energizing 
the  magnet  "A"  in  signal  "B"  and  allowing  that  signal  to 
operate  by  gravity  to  the  "stop"  position.  Second — The  opera- 
tion of  the  controller  switch  to  the  reverse  position  completed 
a  circuit  through  magnet  "A,"  as  follows  :  Current  flows  from 
the  feed  wire  connection  at  station  "A,"  through  magnet  "A," 
through  the  front  contact  of  the  line  relay  "L,"  through  the 
controller  switch,  contact  "LR,"  through  the  winding  of  the 
line  relay  "L"  at  station  "A,"  over  line  wire  2,  through  the 
winding  of  the  line  relay  at  station  "B,"  through  contact  "LR" 
01'  the  controller,  through  contacts  "E"  in  the  signal,  through 
contacts  "RN"  in  the  controller  and  through  a  resistance  to 
ground.  This  circuit  causes  the  signal  "A"  to  remain  in  the 
"clear"  position  unless  the  signal  at  station  "B"  assumes  the 
"stop"  position,  when  the  contacts  "E"  in  that  signal  are 
opened.  Third — Current  flows  from  the  feed  wire  at  station 
"A,"  through  magnet  "A,"  through  a  resistance  and  through 
contacts  "F"  to  ground. 

After  the  controller  switch  is  operated  at  station  "A,"  the 
signal  at  station  "B"  assumes  the  "stop"  position  and  opens 
contacts  "E"  in  that  signal,  and  as  the  car  which  is  entering 
the  block  passes  off  tho  insulated  sections  the  contacts  "F" 
are  opened  and  then  magnet  "A"  is  de-energized  so  the  signal 
operates  away  from  the  "clear"  position.  The  operation  as  the 
controller  switch  completes  a  circuit  is  as  follows  : 


through  contact  "LR"  on  the  controller,  through  the  line  relay 
"I."  at  station  "A,"  over  line  wire  2,  through  the  line  relay  at 
station  "B,"  through  the  contact  "LR"  on  the  controller, 
through  the  contact  "E,"  through  contact  "RN"  on  the  con- 
troller, through  the  controller  switch  and  through  a  resistance 
to  ground.  Second — When  the  controller  switch  was  operated 
as  described  the  second  circuit  was  completed  through  tin1 
magnet  "A"  at  station  "A,"  through  the  line  relays  and 
contact  "E"  in  signal  "B."  This  circuit  kept  the  signal 
"A"  and  the  line  relays  energized  unless  signal  "B"  assumod 
the  "stop"  poistion.  The  line  relays  were  de-energized  as  soon 
as  the  contacts  "E"  opened.  Third— This  circuit  is  completed 
when  a  car  passes  out  of  the  block.  The  controller  switch  is 
operated  to  Its  normal  position  and  current  flows  from  the  feed 
wire  at  station  "A,"  through  a  resistance,  through  the  con- 
troller switch,  through  contacts  "RN"  on  the  controller,  through 
contacts  "E,"  through  contacts  "LR,"  through  the  line  relay 
at  station  "A,"  over  line  wire  2,  through  the  line  relay  at  sta- 
tion "B,"  contact  "LR"  on  the  controller,  through  contacts 
"H,"  through  contact  "RN"  on  the  controller,  through  the  con- 
troller switch  and  through  a  resistance  to  ground.  This  circuit 
energizes  the  line  relays  and  allows  both  signals  to  operate  to 
the  "clear"  position.  Contact  "H"  is  closed  only  while  the  car 
is  on  the  insulated  sections  when  passing  out  of  the  block.  As 
the  signals  assume  their  "clear"  position,  the  contact  "E"  at 
station  "B"  is  closed  so  that  after  the  car  which  is  passing 
out  of  the  block  has  passed  off  the  insulated  sections,  contact 
"H"  Is  opened  and  the  line  relay  circuit  is  maintained,  as  first 
described  above,  through  the  contacts  "E." 

The  following  are  track  relay  and  controller  circuits :  The 
circuit  between  the  setting  relay  and  setting  magnet  on  the 
controller  is  opened  by  contact  "G"  when  the  signal  is  in  the 


IO2 


BLOCK    SIGNALS. 


Figs.  632-633 


"stop"  position.  Whenever  the  signal  is  in  the  "stop"  position 
the  block  is  occupied  and  both  line  relays  are  de-energized.  If 
the  signal  at  station  "A"  is  at  "stop,"  the  signal  at  station 
"B"  is  at  "caution,"  so  that  a  car  entering  the  block  at  sta- 
tion "A"  operates  the  setting  relay  at  station  "A"  and  com- 
pletes a  circuit  through  the  setting  magnet  of  the  controller 
at  station  "B"  as  follows :  Current  flows  from  the  feed  wire  at 
station  "B,"  through  a  resistance,  through  the  setting  magnet 
on  the  controller,  through  contacts  "G"  at  station  "B"  to  the 
setting  relay  at  station  "B"  (but  not  through  the  contacts  on 
that  relay),  then  through  the  back  contacts  of  the  line  relay 
at  station  "B,"  over  line  wire  1,  through  the  back  contacts 
of  the  line  relay  at  section  "A,"  through  the  contacts  of  the 
setting  relay  at  station  "A"  to  ground.  This  operation  of  the 
setting  relay  at  station  "A"  causes  the  setting  magnets  on  th-i 
controller  at  station  "B"  to  operate  when  the  signal, at  station 
"A"  is  at  "stop."  This  movement  of  a  car  passing  a  "stop"' 
signal  is  an  irregular  movement  and  contrary  to  signal  practice 
and  operating  rules  and  should  not  be  made  except  under 
orders  from  the  dispatcher. 

Whenever  a  car  passes  out  of  the  block  and  operates  the 
release  relay  it  energizes  the  release  magnet  of  the  controller 
at  both  ends  of  the  block.  From  the  description  it  is  evident 
that  only  one  controller  has  been  operated  and  the  other  con- 
ti oiler  is  in  the  normal  position.  The  controller  that  has 
operated  is  moved  back  one  step  toward  normal  and  the  con- 
troller that  is  in  the  normal  position  is  not  affected  except 
that  the  contacts  "H"  are  closed.  Circuits  of  the  release  relays 
and  the  release  magnets  on  the  controller  are  connected  by  line 
wire  3,  so  that  the  operation  of  either  release  relay  energizes 
bcth  controller  magnets.  It  is  evident,  then,  that  a  car  may 
pass  out  of  either  end  of  the  block  and  be  properly  counted  out 
and  that  as  the  last  car  passes  out  at  either  end  of  the  block 
the  signals  will  operate  to  the  "clear"  position. 

The  only  functions  of  the  contacts  "H"  are  to  complete  a 
circuit  which  energizes  the  line  relays  as  the  last  car  passes 
out  of  the  block,  as  described  above.  These  contacts  are  required 
only  while  the  car  is  on  the  insulated  sections.  There  is  but 
one  of  these  contacts  required  at  a  time  and  that  is  the  contact 
at  the  end  of  the  block  where  the  signal  is  in  the  "stop" 
position.  The  lamps  in  each  signal  burn  continuously  and 
are  connected  in  series  with  a  resistance  between  the  feeder 
connection  and  ground.  The  wiring  in  the  two  signals  is  the 
same  except  that  the  apparatus  'Which  is  connected  in  series 
over  lines  1  and  2  is  connected  to  the  feeder  wire  at  station 
"A"  and  to  the  ground  at  station  "B." 


EUREKA    SIGNAL    SYSTEM. 

The  signal  system  for  electric  roads  made  by  the  Eureka 
Automatic  Electric  Signal  Co.  consists  of  lamp  or  disc  sig- 
nals, an  electromagnetic  controller,  and  a  trolley  contactor  for 
controlling  the  operating  circuit  when  a  car  enters  and  leaves 
the  block.  Fig.  636  shows  the  control  circuits  for  the  system 
as  first  installed,  using  lamp  signals.  Two  controllers  are  used 
for  each  section  of  track.  These  do  not  operate  in  synchronism. 
When  a  car  enters  a  section  the  controller  at  the  entering  end 
operates  to  set  the  signals  to  stop  at  both  ends  of  the  section. 


cars,  and  the  home  at  that  end  will  be  locked  at  "stop,"  so  that 
the  car  in  the  block  will  be  protected  by  two  signals,  blocking 
cars  coming  from  the  opposite  direction.  Additional  cars  may 
follow  the  first  car  into  the  block.  In  such  case  the  signals 
will  remain  as  set  by  the  first  car,  but  in  the  home  signal  at  the 
entering  end  of  the  section,  the  lights  will  change  with  each 
car  taking  the  block.  When  two  cars  attempt  to  enter  a  block 
at  opposite  ends  at  the  same  time,  neither  can  clear  the  home  ; 
or  if  there  is  a  difference  in  the  time  of  such  attempt,  the  first 
car  in  the  block  will  set  the  home  at  its  end  and  lock  the  other 
home  at  stop,  and  at  the  same  time  set  the  distant  at  the  far 
end  of  the  block.  Should  a  car  go  into  a  block  against  stop 
signals,  both  homes  will  be  set  at  stop  before  the  ovorrunning 
car  can  pass  that  at  its  end,  and  will  remain  so  until  one  of 
tlie  cars  backs  out  of  the  block,  when  the  system  will  be  auto- 
matically set  to  protect  the  car  remaining  in  the  block. 

The  signal  line,  extending  from  end  to  end  of  the  block,  passes 
across  the  base  of  the  controller  through  switches  A,  D,   C  and 


Fig.  633.     Signal  Controller.     Eureka  Automatic  Elec- 
tric Signal  Company. 

F,  and  not  through  the  magnets.  This  signal  line,  when  the 
block  is  not  occupied,  is  grounded  at  both  ends  through  the  con- 
trollers by  means  of  switch  D  and  wire  8  to  the  rail.  Between 
each  controller  and  that  ground  the  distants  are  placed.  By 
means  of  homes  are  placed,  the  signal  here  is  connected  to  the 
source  of  power.  On  the  other  side  of  the  controller  are  two 
switches,  C  and  F,  one  of  which  is  always  open  when  the  other 
is  closed  from  which  a  loop  extends  some  distance  into  the 
block,  in  each  branch  of  which  a  lamp  is  wired,  both  located  in 
the  "home"  signal,  one  always  being  lighted  when  the  other  is 
not. 

When  both  controllers  are  set  to  ground,  switches  D  being 
closed,  no  current  can  flow  and  there  can  be  no  operation ;  and 
when  both  controllers  are  operated  to  connect  the  signal  line 
to  the  source  of  power,  switches  A  being  close  and  D  open,  no 
current  can  flow  and  there  can  be  no  operation.  Only  when 
one  controller  is  operated  to  close  switch  A,  connecting  in  that 


Fig.  632.     Trolley  Contact  Maker.     Eureka  Automatic  Electric  Signal  Company. 


Should  cars  attempt  to  enter  the  block  at  opposite  ends  at  the 
same  time,  both  controllers  would  operate  to  counteract  each 
other  and  the  home  signals  at  both  ends  of  the  block  would  be 
locked  at  "stop."  The  upper  is  the  home  and  the  lower  the 
distant  signal.  When  block  is  occupied  both  home  and  distant 
signals  at  the  entering  end  of  the  section  are  clear  and  both 
home  and  distant  signals  at  the  leaving  end  of  the  section  are 
at  "stop."  When  block  is  unoccupied,  the  home  signals  at  both 
ends  of  the  section  are  at  stop  and  the  distant  signals  at  both 
ends  are  at  clear.  When  the  signals  are  in  this  position  a  car 
may  enter  a  block  at  either  end,  provided  the  home  goes  to 
clear  when,  the  contact-maker  has  been  passed,  if  approaching 


controller  the  signal  circuit  through  wire  1  to  source  of  power, 
leaving  the  ground  through  the  other  controller  intact,  can  the 
home  signal,  normally  at  stop,  be  cleared  and  the  distant  put 
at  "stop." 

Fig.  636  shows  two  contact-makers  the  simpler  method  of 
installation  ;  but  where  spring  switches  are  used  in  the  track 
which  cannot  be  hand  operated,  it  is  preferable  to  use  four 
contact-makers,  two  at  each  end  of  the  block,  one  placed  over 
each  branch  of  the  siding.  The  use  of  four  contact-makers  al- 
lows the  signals  to  operate  before  the  car  passes  through  the 
track  switch,  which  if  once  passed  requires  the  car  to  back 
around  the  turnout  in  case  it  cannot  go  through  the  block.  The 


Figs.  634-636 


BLOCK  SIGNALS. 


103 


•'direction  switches"  G  B  H  and  G'  B'  H'  normally  connect 
B  and  G  and  B'  and  H'.  The  energizing  of  magnets  MM  reverses 
switch  G  B  H  and  of  magnets  M'M'  switch  G'  B'  H'.  When  a 
car  enters  a  block  the  trolley  wheel  closes  the  trolley  contactor 
so  that  current  flows  from  first  half  of  contact-maker  through 
wire  7  to  fuse  block,  thence  through  closed  "direction  switch" 
from  B'  to  H',  across  base  of  controller  through  block  H  of 
other  "direction  switch,"  thence  through  upper  resistance  and 
magnets  MM  to  ground  through  wire  2.  This  cuts  the  signal 
line  into  feed  connection  and  also  sets  the  "direction  switch" 
from  BG  to  BH,  so  that  when  the  trolley  wheel  reaches  the 
second  half  of  contact-maker,  current  will  flow  through  wire  3 
to  fuse  block,  thence  through  "direction  switch"  from  B  to  H, 
and  continue  through  upper  resistance  and  magnets  MM,  caus- 
ing current  to  flow  from  entire  length  of  contact-maker  through 
magnets  MM.  Additional  cars  going  Into  the  block  repeat  this 
operation.  When  a  car  has  passed  through  the  block,  upon 
leaving  it  the  trolley  wheel  first  makes  contact  so  that  current 
flows  from  the  "finger  plate"  in  connection  with  wire  3  to  fuse 
block,  thence  through  "direction  switch"  from  B  to  G  and 
across  base  of  controller  through  G'  to  lower  resistance,  where 
the  current  divides.  A  portion  goes  through  that  resistance 
and  magnets  M'M'  to  ground,  across  base  of  controller  through 
wire  2,  thus  setting,  by  means  of  magnets  M'M'  "direction 
switch"  from  B'H'  to  B'G'.  This  causes  the  current,  when 
second  half  of  contact-maker  Is  reached,  to  flow  through  "direc- 
tion switch"  from  B'  to  G'  by  way  of  wire  7  and  fuse  block, 
lower  resistance,  and  magnets  M'M'  to  ground.  The  other  por- 
tion of  the  current  which  divided  at  lower  resistance,  passes 
out  by  wire  6  to  other  end  of  block  through  switch  O  of  auxiliary 
controller,  and  In  by  wire  6  to  and  through  lower  resistance  at 
that  end ;  thence  direct  through  magnet  M'M'  to  ground,  as 
previously  explained,  thus  operating  magnets  M'M'  to  cut  out 
the  signal  line  from  feed  connection.  This  holds  good  for  cars 
passing  through  the  block  from  either  end.  The  current  coming 
In  by  wire  6  cannot  flow  along  the  wire  with  which  it  connects 
at  lower  resistance  because  that  circuit  will  be  open  at  the  con- 
tact maker. 


Fig.  634.     Circuit  for  Continuous  Block  Signal  Indica- 
tion.    Eureka  Automatic  Electric  Signal  Company. 


The  function  of  magnets  JJ  is  to  hold  switch  O  open  when 
magnets  II  are  energized  to  close  It,  as  occurs  immediately 
when  the  trolley  wheel  makes  contact  with  the  finger  plates  ot 
contact-maker.  They  hold  it  open  until  the  trolley  wheel  has 
passed  through  the  entire  length  of  the  finger  plates.  These 
magnets  JJ  receive  only  suflicient  current  through  the  resistance 
in  series  with  them  to  energize  them  to  hold  open  switch  O,  the 
current  being  too  feeble  to  operate  the  main  controller  through 
which  It  continues  to  ground. 


Fig-  635.     12-Inch   Disappearing   Disk.     Eureka  Auto- 
matic Electric   Signal  Company. 


Fig.  636.     Signal  Control  Circuits.     Eureka  Automatic  Electric  Signal  Company. 


When  a  car  has  entered  the  block  and  the  signal  line  has 
been  cut  into  the  feed  connection,  the  current  flowing  through 
it  lights  the  lamps  and  energizes  magnets  II  of  the  auxiliary 
controller  to  close  switch  O.  This  switch  thus  always  closes 
when  cars  enter  only  at  one  end  of  the  block  and  pass  through 
and  out  of  it  at  the  other  end.  Should  cars  enter  at  both  ends 
— at  one  end  in  defiance  of  the  signals  or  by  overrunning,  and 
thus  connect  the  signal  !ine  to  the  source  of  current  at  both 
ends — no  current  can  flow  through  magnets  II,  and  switch  0 
will  be  open. 


Fig.  634  shows  the  control  circuits  for  a  continuous  block 
signal  Indication  using  the  same  trolley  contactor  and  controller 
as  described  above  but  giving  indications  by  a  12  in.  disappear- 
ing disk  as  shown  In  Fig.  635.  When  power  in  on  the  line  the 
semaphores  are  normally  at  clear,  and  when  the  power  goes 
off  the  semaphores  fall  to  danger.  When  a  car  enters  the  block, 
the  semaphores  go  to  danger  and  are  locked  at  danger  until 
the  car  leaves  the  block  at  the  other  end.  Should  the  power  go 
off  while  the  car  Is  In  the  block,  the  semaphores  will  remain 
at  danger  until  the  car  leaves  the  block. 


104 


BLOCK    SIGNALS. 


Figs.  637-638 


INSTALLATIONS 


NEW  YORK  CENTRAL  ELECTRIC  ZONE. 

The  following,  which  Is  a  description  of  the  latest  installa- 
tion, made  by  the  General  Railway  Signal  Co.  on  the  Electric 
Zone  of  the  New  York  Central  &  Hudson  River  Railroad,  illus- 
trates and  describes  a  typical  automatic  block  signal  system 
for  a  direct  current  electric  road  having  the  heaviest  type  of 
traffic,  alternating  current  being  employed  for  the  operation 
of  the  track  circuits  and  all  the  signal  devices. 

The  prominent  features  of  this  installation  are  the  re- 
tention of  both  rails  for  propulsion  current  through  the  use  of 
Iron  core  reactance  bonds;  the  operation  of  long  track  circuits, 
made  possible  by  the  efficiency  of  the  polyphase  relays  and  by 
the  bonds  having  a  higher  reactance;  the  signals  of  the  single- 
arm,  three-position,  semaphore  type,  operating  directly  over  the 
line;  and  the  general  reduction  of  the  amounts  of  apparatus 
required. 

The  25-cycle,  single-phase,  alternating  current  used  for  the 
operation  of  the  signal  system  is  normally  obtained  from  the 
railroad  company's  11,000-volt,  25-cycle  bus  bars,  stepped  down 
by  means  of  static  transformers,  to  2,200  volts  for  distribu- 
tion. As  a  reserve,  in  case  of  failure  of  the  11,000-volt  power, 
motor  generators  are  installed  taking  power  from  the  railway 
company's  650-volt  storage  battery.  The  switchboard  circuits 
are  arranged  so  that  the  transformer  and  motor-generator  can 
operate  singly  or  in  multiple  as  desired. 

The  substations  are  located  approximately  six  miles  apart, 
varying  in  capacity  from  60  to  100  k.  w.  In  addition  to  the 
power  required  for  the  block  system,  these  substations  also 
supply  the  power  for  charging  the  battery,  operating  motor- 
generator  sets,  signal  lights,  indicators,  relays,  etc.,  which  are 
located  in  the  various  interlocking  plants  on  the  Electric  Zone 
territory. 

The   transmission    line   is    interrupted    between    adjacent   sub- 


over  the  line,  thereby  eliminating  the  line  relays,  which  in  auto- 
matic work  are  ordinarily  used  to  control  the  signal  operation. 
Group  No.  1  of  the  diagram  illustrates  the  saving  due  to  the 
use  of  this  signal. 

The  second  group  shows  a  reduction  in  relays  for  track  cir- 
cuit control,  the  four-point  Model  1  polyphase  relay,  replacing 
the  old  single  point  type  of  polyphase  with  its  Model  19  sec- 
ondary relay. 

The  third  group  shows  clearly  the  saving  In  gross  weight  of 
reactance  bonds.  This  has  been  brought  about  by  the  use  of 
bonds  of  higher  reactance,  relays  of  higher  efficiency  and  the 
consequent  installation  of  longer  track  circuits.  Therefore, 
where  five  years  ago,  six  bonds  were  required  to  the  mile,  but 
two  bonds  are  now  necessary  and  those  of  very  much  smaller 
size ;  this  resulting  in  a  decrease  in  weight  of  the  bonds  from 
3,750  to  925  pounds  per  mile,  or,  in  other  words,  a  reduction 
in  the  ratio  of  about  four  to  one. 

A  comparison  of  transformer  apparatus  is  illustrated  by  the 
fourth  group,  the  present  transformer  being  wound  to  operate 


Fig.  637.     Model  "2-A"  A.  C.  Automatic  Signal  Bridge, 
N.  Y.  C.  &  H.  R.  R.  R. 


Fig.  638.     Transformer  and  Grid   Box  on  Pole. 
York  Central  Electric  Zone. 


New 


stations,  so  that  normally  each  substation  feeds  out  one  way, 
being  independent  of  its  neighbor ;  this  is  to  avoid  the  need 
of  keeping  them  in  synchronism  and  to  prevent  trouble  on  one 
section  from  affecting  adjacent  sections.  In  case  of  emergency, 
however,  the  transmission  lines  can  be  so  connected  that  a  given 
substation  will  feed  out  on  to  the  lines  in  both  directions.  On 
these  later  installations,  aerial  transmission  lines  are  used 
entirely,  consisting  of  No.  0  hard  drawn  copper  wire,  strung 
on  the  railway  company's  transmission  line  poles. 

Before  taking  up  the  detailed  description  of  the  signal  appli- 
ances it  will  be  interesting  to  note  the  advance  in  the  art  of 
signaling  during  the  past  five  years.  The  diagram,  Fig.  639, 
shows  graphically  the  amount  of  apparatus  required  at  a  signal 
location  at  the  present  time,  as  compared  with  that  which  was 
used  on  the  earlier  installations  which  were  made  on  the  Electric 
Zone. 

The  two-arm,  two-position  signals  used  on  the  earlier  work 
have  been  supplanted  by  the  single-arm,  three-position  signals  of 
the  Model  2-A  type.  The  Model  2-A  signal  is  operated  directly 


not  only  the  signals,  etc.,  but  also  the  track  circuits,  whereas 
on  the  former  installations  the  track  circuits  were  fed  by  small 
secondary  transformers. 

The  noticeable  decrease  in  energy  consumption  from  600 
watts  (750  volt-amperes)  to  200  watts  (240  volt-amperes)  per 
signal  location  is  due  to  the  increased  efficiency  in  the  signal 
and  track  relay  apparatus  and  the  elimination  of  secondary 
relays,  transformers,  cut-sections,  etc. 

Fig.  638  illustrates  a  typical  transformer  location,  the  grid 
box  and  transformer  being  mounted  on  the  pole.  As  shown  on 
circuits  in  Fig.  641,  transformers  are  required  near  sig- 
nals, at  the  middle  of  center-fed  track  sections,  and  at  the 
ends  of  all  track  sections.  Those  at  the  signal  locations  nec- 
essarily have  more  secondary  windings  than  the  others,  the 
secondaries  consisting  of  a  coil  with  taps  giving  voltages  of 
•approximately  170,  55  and  17  for  the  operation  of  signals, 
lighting  circuits  and  relay  locals  respectively,  a  55-volt  coll 
for  the  local  control  of  relays  not  located  at  the  transformer 
in  question  (see  circuits,  Fig.  641)  and  from  one  to  three  coils 


Figs.  639-641 


BLOCK    SIGNALS. 


105 


for  track  feed,  the  different  taps  giving  voltages  which  vary 
from  two  to  eight  volts.  The  secondary  coils  are  Independent 
of  each  other,  each  terminating  in  binding  posts  located  within 
the  transformer,  thus  doing  away  with  a  number  of  external 
leads  which  may  or  may  not  be  required.  Plug  cut-outs  are 
used  in  the  primary  circuit  so  that  the  transformer  may  be 
disconnected  from  the  transmission  lines  without  danger. 

Fig.  643  shows  a  typical  installation  of  the  iron  core  react- 
ance bonds  used  in  connection  with  double-rail  a.  c.  track 
circuits.  The  bonds  are  wound  with  10  turns  of  cop- 
per, having  sectional  area  of  750,000  circular  mils,  with 
a  continuous  carrying  capacity  per  track  of  2,000  amperes, 
a  short-time  overload  of  3,400  amperes,  and  an  unbalancing 
capacity  of  over  400  amperes,  the  latter  without  varying  the 
reactance  over  five  per  cent.  The  resistance  of  the  bond  to 
alternating  current  is  approximately  1-10  of  an  ohm.  The 
colls  of  the  bond  are  immersed  in  transformer  oil. 

The  copper  connections,  after  leaving  the  bond  terminals,  go 
downward  and  underground  to  the  rails,  where,  after  passing 


J— L       S    FIGUEE     1    < 


r 


I    ARM 
3   POSITION    SIGNAL 


n 


TRACK       BELAY 


I     i -i        9Z5     LB.S  =  VYEIGHT 

FIGURE.    3    <^     02J     !  OF    BONDS    PER 

'-J  MILE    OF    TRACK 


LINE.   TRANSFORMER 


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SECONDARY  IwwJ     | 

TRANSFORMER  f^|  f^| 


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S      IWWVj  W  K/VI 


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PER  SIGNAL  LOCATION 
PER  MILE  OF  TRACK 


<, 1    ZOOVYATT5- (240  YA.) 
^ ^    PER    SIQNflL  LOCATION 

PER    MILE  OF  TRBCK 


Fig.  639.     Diagram  Showing  Progress  Made  in  Signal- 
ing on  N.  Y.  C.  E.  Z.  During  Past  Five  Years. 

for  a  short  distance  above  ground  to  insure  flexibility,  they 
are  connected  to  the  rails.  The  bond  connections  to  the  rails 
consist  of  two  500,000  circular  mil  flexible  cables  in  multiple. 
The  track  relay  at  present  employed  on  the  Electric  Zone 
Is  the  Model  1  polyphase,  the  relay  being  provided  with  four 


a  small  amount  of  energy  from  the  track  to  give  positive  action 
to  the  contacts,  and  as  a  result,  long  track  circuits  can  be 
operated  with  minimum  of  energy.  The  various  moving 


Fig.  640.     Model  "2-A"  Block  Signal,  N.  Y.  C.  E.  Z. 

contacting  parts,  which  are  mounted  on  a  horizontal  wooden 
bar,  are  of  unusually  heavy  construction,  having  a  wide  opening, 
and  by  rubbing  through  the  last  1-16  in.  of  their  stroke  in 
closing  they  maintain  a  clean,  low  resistance  contact.  Con- 
tacts and  all  other  working  parts  are  visible  through  glass- 


Fig.   641.     Typical    Arrangement   of   Circuits   for   A.    C.   Automatic  Signals.     N.  Y.  C.  E.  Z. 


front  and  four  back  contacts.  It  is  operated  by  a  two-phase 
induction  motor,  one  phase  of  which  is  connected  to  the  rails 
and  the  other  to  the"  track  transformer,  Fig.  641.  Of  the 
energy  in  the  two  relay  windings,  that  supplied  by  the  trans- 
former direct  is  by  far  the  greater.  It,  therefore,  requires  but 


covered    openings.     The    relay    Is    insulated    to    stand    a    break- 
down test  of  3,000  volts  alternating  current. 

The  signals,  as  mentioned  above,  are  of  the  single-arm,  three- 
position,  Model  2A  type.  They  are  designed  to  operate  on  a 
voltage  of  150  a.  c.,  clearing  the  blade  from  0  to  90  deg. 


io6 


BLOCK    SIGNALS. 


Figs.  642-644 


Fig.  642.     Track  Box  Location.     N.  Y.   C.  E.  Z. 


Fig.  643.     Double  Bond  Location.     N.  Y.  C.  E.  Z. 


through  three  positions  in  five  seconds.  As  shown  in  Fig.  641, 
the  signal  Is  controlled  locally  for  the  45-deg.  position  and 
over  the  line  directly  for  the  90-deg.  position.  A  complete 
description  of  the  signal  mechanism  is  given  under  Automatic 
Block  Signal  mechanisms. 

Fig.  640  shows  a  single  automatic  semaphore,  Fig.  637  a  typ- 
ical four-track  bridge  equipped  with  same  and  Figs.  649  and 
650  show  views  of  the  type  of  light  signals  installed  in  the 
Park  Avenue  tunnels  immediately  outside  of  the  New  York 
City  Terminal. 

Fig.  641  shows  a  complete  typical  block  circuit,  four  signals 
being  illustrated  to  present  the  circuit  combinations  from  clear 
to  stop.  Attention  Is  called  to  the  following  features :  The 
direct  90-deg.  control  of  the  signals;  the  use  of  end  and 
center-fed  track  sections;  the  practice  of  restricting  switch 


selection  to  the  local-phase  wire  of  the  relay  at  a  signal  loca- 
tion, thus  keeping  the  high  voltage  wires  out  of  the  switch 
boxes;  and  the  protection  afforded  this  local  wire  against 
crosses  with  signal  control  wires  through  the  use  of  opposing 
polarities.  To  avoid  confusion,  the  detail  mechanism  wiring 
for  the  signals  Is  omitted  (see  page  76),  it  being  understood 
that  when  current  is  applied  to  a  control  wire,  the  arm  will 
clear.  The  various  devices  represented  in  Fig.  641  have  been 
described  and  the  operation  of  these  circuits  will  be  evident 
without  further  explanation. 


Fig.    644.     Universal    Model    "2-A"    Direct    Connected 

Signal  Mechanism,  A.  C.  Commutating  Motor. 

General  Railway  Signal  Company. 


LEHIGH   VALLEY    TRANSIT  COMPANY. 

The  Lehlgh  Valley  Transit  Co.  operates  a  high-speed  single- 
track  electric  line,  using  direct  current  at  600  volts  for  trac- 
tion purposes.  On  a  section  of  this  line  Is  installed  the  G.  R.  S. 
Co.'s  "Absolute  Permissive"  block  system  of  signaling. 

Energy  for  the  operation  of  the  signal  system  Is  stepped  down 
by  type  "H"  transformers  at  all  track  feed  and  signal  locations, 
from  the  2,300-volt,  25-cycle  transmission  line  along  the  right- 
of-way.  The  transformers  are  provided  with  a  55-volt  winding 
for  the  operation  of  the  signals,  for  relay  locals,  and  for  the 
lighting  circuits,  and  with  independent  windings  having  a 
range  of  from  two  to  six  volts  for  the  various  track  circuits. 

Double-rail  track  circuits,  using  iron  bonds,  are  installed  be- 
tween sidings  and  single-rail  circuits  on  the  short  sections 
through  the  sidings.  Fig.  648  illustrates  the  installation  of  a 
reactance  bond  where  a  two-rail  track  circuit  abuts  with  a 
single-rail  circuit.  Fig.  645  shows  a  double  bond  location  where 
two  double-rail  circuits  are  adjacent. 

By  bonding  together  the  power  rails  of  the  two  tracks  In 
the  sidings,  two  rails  are  made  available  for  the  return  of  th* 
propulsion  current  throughout  the  signaled  territory. 

The  relays  installed  are  the  G.  R.  S.  Co.'s  Model  2,  Form  A 
polyphase.  On  one  center-fed  track  circuit  two  miles  long  this 
relay  required  but  four  volts  and  10  amperes  (40  v.  a.),  the 
section  having  dirt  banked  up  near  to  the  top  of  one  rail 
throughout  its  entire  length  and  up  to  the  toy  of  both  rails 
at  the  20-odd  road  crossings  within  the  section.  In  another 
center-fed  track  circuit,  4,000  feet  long,  the  track  conditions 
are  as  illustrated  in  Fig.  646.  Furthermore,  a  reactance  bond 
is  connected  across  the  rails  near  the  center  of  this  section,  to 
provide  a  negative  return  for  another  branch  of  the  company's 
lines.  This  track  circuit  requires  five  volts  and  22  amperes 
(110  v.  a.)  for  strong  relay  operation,  the  major  portion  of  this 
current  flowing  through  the  reactance  bond  at  the  center  of  the 
track  section. 

The  signals  are  G.  R.  S.  Model  2A,  operated  by  55  volts. 
25  cycle  a.  c.  In  order  to  prevent  delay  to  the  following  sections 
of  a  train,  a  permissive  indication  is  given  which  consists  of 
a  yellow  light  displayed  half  way  up  the  signal  mast.  When 
a  car  has  entered  the  block  and  put  the  signal  arm  to  the 
stop  position  the  cautionary  yellow  light  will  be  shown,  advising 
a  car  following,  that  another  has  preceded  it  and  that  it  la  safe 
to  enter  the  block  under  caution. 

The    signals    governing    in    one    direction    normally    stand    at 


Figs.  645-648 


BLOCK   SIGNALS. 


107 


danger   and    in   the  other   In   the   clear   position,    the   control   of 
the  normal  clear  signals  overlapping  that  of  the  opposing  normal 


figure    in    the    diagram    shows    train    "E"    at    a    predetermined 
meeting  point  and  having  a  clear  signal,  thus  holding  train  "D" 


Fig.    645.     Track   Feed    Location.      Lehigh    Valley 
Transit   Company's   Railways. 


danger  signals  through  the  preliminary  clearing  section,  as 
shown  in  the  first  diagram  of  Fig.  647.  Opposing  signals  gov- 
erning into  a  given  piece  of  single  track  are  electrically  inter- 
locked in  such  a  manner  that  one  must  be  at  stop  before  the 
other  can  give  either  a  proceed  or  permissive  indication.  The 


•rno- 


Fig.    646.     Typical    Section    of   Track.      Lehigh    Valley 
Transit  Company's  Railways. 


at  the  next  siding.  The  conductor  of  train  "E"  by  inserting  a 
key  in  a  small  box,  located  near  the  signal,  can  place  signal  2 
at  stop,  thus  permitting  signal  1  to  clear,  advancing  train  "D" 


Siding  Xf-2-^* 

S/ding  Y   <—S—^3 

Siding  Z. 

ii  H 

•  U  4    ' 


f/G.Z 


r/o.3 


r/a.  6 


Fig.  647.     Diagram  Showing  Train  Operation.     Lehigh 
Valley  Transit  Company's  Railways. 


Fig.   648.     Single    Bond   Location.     Relays    Housed   at 
Base  of  Signal.     Lehigh  Valley  Transit  Company. 


circuit  prevents  a  false  proceed  or  permissive  indication  being 
given   through   breaks   or   crosses   in  the  line. 

The  series  of  diagrams  show  train  "A"  approaching  and  pass- 
Ing    trains    "B"    and    "C,"    running    in    two    sections.      The   last 


to  the  regular  passing  siding.  After  "D"  has  passed,  the  motor- 
man  or  conductor  on  train  "E->  must  turn  the  key  back  and 
withdraw  it  before  signal  2  can  be  cleared  again,  to  allow  his 
train  to  leave  the  siding. 


io8 


BLOCK   SIGNALS. 


Figs.  649-653 


Figs.   649-650.     Light   Signal,    Park  Ave.   Tunnel, 
N.  Y.  C.  E.  Z. 

HUDSON  &    MANHATTAN   RAILROAD. 

The  signaling  in  the  Hudson  tunnels  covers  the  four  miles 
of  double-track  road  between  the  station  at  33d  street,  New 
York,  and  that  at  Hoboken,  N.  J.  The  system  is  designed  to 
provide  for  a  two-minute  interval  service  and  affords  to  a 
train  the  protection  of  three  home  and  four  distant  signals. 
Automatic  stops  are  installed  to  prevent  a  train  overrunning 
a  home  signal  when  in  the  stop  position. 


Figs.  651-652.     G.  R.   S.  Light  Signal— Day  and  Night 

Indications.     Arrestive   Indication   Given  from 

1,200  to   1,500  ft.  in  Bright  Sunlight  and 

with  Covering  of  Fresh  Snow 

on  Ground. 

shown  in  Fig.  658,  the  relay  box  is  mounted  above  the  case 
containing  the  control  apparatus  for  the  automatic  stop.  Fig. 
661,  illustrating  a  typical  signal  location,  shows  the  relay 
box,  junction  boxes  and  transformer  at  the  back  of  signal 
160,  and  the  automatic  stop  and  reactance  bond  between  the 
rails  of  the  track. 

Light    signals    of    the    shutter    type     (Fig.    659-660)     are    in- 
stalled,   one   case   housing   both    home   and   distant   mechanisms. 


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Fig.  653.     Diagram  of  Block  Signal  Circuits.     Hudson  &  Manhattan  Railroad. 


Names  of  Parts  of  Fig.  653. 

A    Resistance  Coil  D  S    Distant  Signal 

B     Iron  Core  Reactance  Bond  G    Resistance  Grid,  Adjustable 

C     Contact  Closed  by  Automatic  Train  Stop       H  S     Home  Signal 


L  T    Line    and    Track    Transformer 

R    Reactance  Coil 

T  R    Polyphase    Track    Relay 


The  tracks  are  paralleled  by  a  25-cycle,  1,100-volt  line,  this 
voltage  being  stepped  down  by  G.  R.  S.  Type  "H"  trans- 
formers at  the  signal  locations  to  the  various  voltages  required 
for  the  operation  of  the  system. 

Both  rails  are  retained  for  the  return  propulsion  current 
by  the  use  of  iron  core  reactance  bonds  (Figs.  654-655).  The 
track  relays  are  the  G.  R.  S.  Co.'s  Model  1  polyphase.  As 


The  shutter  which  passes  between  the  electric  lights  and  the 
signal  lenses  is  actuated  through  a  gear  and  pinion  movement 
by  a  two-phase  Induction  motor  (Figs.  656-657),  similar  to  the 
Model  1  polyphase  relay.  Each  signal  is  lighted  by  two 
incandescent  lamps,  connected  In  multiple  and  arranged  so 
that  should  one  be  extinguished  the  other  will  continue  to 
throw  light  through  both  of  the  signal  lenses,  giving  an 


Figs.  654-660 


BLOCK   SIGNALS. 


109 


Fig.    654.     Reactance    Bond,    Hudson    &    Manhattan        Fig.   655.     Reactance   Bond,   Coils  and   Core.     Hudson 
Railroad.  &  Manhattan   Railroad. 


rig.   656.     Front   View   of   Tunnel    Signal   Mechanism.      Fig.    657.     Rear    View    of   Tunnel    Signal    Mechanism. 
Hudson  &  Manhattan  Railroad.  Hudson    &   Manhattan    Railroad. 


i 


Fig.  658.    Relay  Box;  Train  Stop  Con-  Fig.    659.     Front   View    of    Tunnel  Fig.   660.     Rear  View  of  Tunnel 
trol    Apparatus    in    Bottom    Com-                Signal,  Hudson  &  Manhattan  Signal    with    Door    of    Case 

partment.      Hudson   &  Man-  Railroad.  Open.     Hudson  &  Man- 

hattan   Railroad.  hattan  Railroad. 


no 


BLOCK   SIGNALS. 


Figs.  661-663 


Indication  of  reduced  intensity,  so  that  the  trouble  will  be 
observed  and  the  lamp  replaced.  The  home  mechanism  is 
equipped  with  the  contacts  necessary  to  the  control  circuits 
shown  in  Fig.  653. 

It    will    be    seen    by    referring    to    the    typical    circuits     (Fig. 
653)   that  the  home  signals  are  controlled  by  a  double  overlap, 


Fig.  661.     Union  Light  Signal.     Hudson  &  Manhattan 
Railroad. 

and  the  distant  signals  through  the  home  signal  in  advance. 
The  control  circuit  for  the  home  signal  is  so  broken  through 
the  contact  on  the  automatic  stop  that  it  may  be  cleared 
only  when  the  stop  is  in  such  position  as  to  allow  the  passage 
of  a  train.  To  simplify  Fig.  653,  the  wiring  and  control 
circuits  for  the  automatic  stops  are  omitted. 


SUSPENDED    LIGHT    SIGNALS    ON    PENNSYLVANIA   TERMINAL. 

With  what  may  be  regarded  as  perpetual  night  conditions 
within  th»  tunnels  and  in  the  larger  portion  of  the  terminal 
track  area,  the  use  of  signals  having  arms  or  blades  for  defin- 
ing their  positions  was  of  secondary  importance  on  the  Penn- 
sylvania Tunnel  &  Terminal  signal  work.  This  fact,  coupled 
with  the  usual  close  quarters  encountered  in  such  places, 
prompted  the  total  elimination  of  the  arms  from  all  block  sig- 
nals in  the  tunnels  and  from  all  but  the  ground  or  dwarf 
signals  on  the  terminal  area. 

The  form  of  signal  which  was  used,  therefore,  had  need  for 


SECTIONAL  SIDE  VIEW 


FRONT    VIEW 


Fig.  662.     Suspended  Five-Light  Electric  Light  Inter- 
locking   Signal.     Union    Switch    & 
Signal  Company. 

no  other  mechanism  than  that  required  for  changing  the  colors 
of  a  system  of  stationary  lights  in  such  a  manner  as  to  repro- 
duce the  same  colors  and  combinations  as  these  produced  by 
changes  in  position  of  the  semaphore  type  of  signal  under  like 
changes  in  the  controlling  currents.  These  signals  -are,  there- 
fore, simply  receptacles  carrying  colored  lenses  behind  which 


Fig.  663.     North  End  of  the  Hudson  River  Tube.     Pennsylvania  Tunnel  and  Terminal  Railroad. 


Figs.  664-666 


BLOCK    SIGNALS. 


in 


9 


SECTIONAL    SIDE     VIEW 


FRONT    VIEW 


"" 


664.     Suspended  Four-Light  Electric  Light  Auto- 
matic Signal.     Union  Switch  &  Signal 
Company. 

are  located  standard  four  candle-power  incandescent  lamps  (two 
In  multiple  for  each  lens),  and  the  "mechanism"  consists  of 
simple  relays  (housed  in  separate  shelters  near  the  signal)  the 
contacts  of  which  were  adapted  to  shift  the  current  from  lamps 
to  lamps  and  thus  to  change  the  colors  displayed  as  the  relays 
are  energized  and  de-energized. 


WASHINGTON    WATER    POWER    COMPANY'S    RAILWAYS. 

This  installation,  made  by  the  General  Railway  Signal  Com- 
pany, covers  20  miles  of  single  track  between  Spokane  and  the 
towns  of  Medical  Lake  and  Cheney,  in  the  state  of  Washington. 
The  installation  consists  of  a.  c.  signals  equipped  with  auto- 
matic stops  of  the  overhead  type,  double-rail  track  circuits  using 
iron  core  reactance  bonds,  polyphase  relays,  etc.,  the  system 
operating  on  the  principles  which  are  described  under  the 
heading,  "The  Alternating  Current  Track  Circuit."  The  In- 
stallation may  be  said  to  be  similar  to  the  one  on  the  New 
York  Central  Electric  Zone  (page  104)  with  certain  modifica- 
tions and  additions  which  are  covered  herein. 


Fig.  665.     Multiple  Unit  Electric  Light  Signal  with 
Cap.     Union  Switch  &  Signal  Company. 

any  line  is  less  than  10  per  cent,  even  though  all  the  signals 
were  cleared  at  the  same  instant.  The  line  is  protected  at  half- 
mile  intervals  with  suitable  high  tension  lightning  arresters. 

Model  H  transformers,  made  by  the  General  Railway  Sig- 
nal Co.,  are  installed  at  signal  and  track  feed  locations 
to  step  down  from  the  2,200-volt  lines  to  the  various  voltages 
required  for  the  operation  of  the  signal  system.  Independent 
secondary  windings  are  provided  for  each  track  circuit  and 
for  the  signal  operating,  lighting,  and  relay  local  circuits. 
Track  secondary  windings  are  furnished  with  taps  ranging 
from  one  and  one-half  to  eight  volts,  the  different  voltages 
being  necessary  to  meet  the  requirements  of  varying  lengths 
of  track  sections;  the  signal  secondaries  provide  220  volts 
for  signal  operation  with  taps  of  55  volts  for  signal  lighting 
and  28  volts  for  the  relay  local  windings;  all  of  which  taps 
are  taken  to  a  terminal  board  for  convenient  connection  to 
the  external  circuits.  The  transformers  are  mounted  on  stub 
poles  as  shown  in  Fig.  671. 

Two-rail  track  circuits  are  used  so  that  both  rails  are  avail- 
able for  the  returning  propulsion  current,  the  track  being 
divided  into  block  sections  of  from  175  ft.  to  15,150  ft.  by 
the  means  of  insulated  rail  joints  and  reactance  bonds.  On 
account  of  the  fact  that  the  trains  operated  are  not  as  heavy, 
nor  the  service  as  frequent,  as  on  the  New  York  Central  Elec- 
tric Zone,  a  much  smaller  reactance  bond  is  used.  The  method 


Fig.  666.     Typical   Circuits.     Washington  Water  Power    Co.'s   Railway. 


The  cars  are  operated  by  600-volt  direct  current  obtained  from 
motor  generator  sets  supplied  from  the  60,000-volt,  60-cycle 
line  paralleling  the  track.  Sixty-cycle  alternating  current  is 
used  for  the  operation  of  all  parts  of  the  signal  system,  current 
being  available  at  a  power  substation  located  approximately  in 
the  center  of  the  district  to  be  served.  The  current  is  deliv- 
ered to  the  bus  bars  of  the  signal  switchboard  at  2,200  volts, 
whence  it  is  distributed  to  the  transmission  lines  through  auto- 
matically tripped  oil  circuit  breakers  equipped  with  I.  T.  E., 
time  limit  relays  and  alarm  bell.  The  transmission  line  con- 
sists of  two  No.  10  H.  D".,  T.  B.,  W.  P.,  line  wires  strung  under 
the  main  transmission  line  on  the  same  poles,  this  size  having 
such  carrying  capacity  that  a  maximum  drop  at  the  end  of 


of  installation  of  these  track  bonds  between  the  rails  is  shown 
in  the  illustration,  Fig.  671. 

The  relays  used  in  connection  with  the  track  circuits  are  the 
General  Railway  Signal  Co.'s  Model  1  polyphase,  being  provided 
with  four  front  and  four  back  contacts.  The  relay's  efficiency 
has  been  demonstrated  by  its  perfect  operation  over  continuous 
track  circuits  approximately  three  miles  long  and  in  the  absence 
of  the  best  conditions  as  to  ballast  and  track  leakage. 

The  signals  installed  are  of  the  Model  2  A  type,  operat- 
ing through  two  positions,  0  to  45  deg.,  in  the  left-hand 
upper  quadrant.  This  being  a  single  track  line,  the  signals 
are  suitably  overlapped  to  provide  the  desired  protection.  Dis- 
tant signals  are  installed  whore  the  view  of  a  home  signnl 


112 


BLOCK   SIGNALS. 


Figs.  667-671 


is  obstructed  on  account  of  curvature  or  heavy  grades.  As 
shown  in  Fig.  666,  signals  operate  directly  over  the  line  without 
the  use  of  line  relays,  the  longest  distance  over  which  a  signal 
is  so  controlled,  on  this  installation,  being  about  three  and 
one-half  miles. 


train  passing  a  signal  in  the  stop  position,  means  are  provided 
whereby  the  arm  may  be  raised  by  hand  for  the  passage  of  a 
train,  this  being  accomplished  by  the  insertion  of  a  key  in  a 
lock  provided  for  the  purpose,  which  key  cannot  be  removed 
until  the  signal  arm  has  again  been  restored  to  the  normal 


The  automatic   stop   is   of   the   overhead  type   and   consists  of.       position. 


Fig.  667.     Model  "2- A"  A.   C.   Signal.     Arm  at   Proceed. 

an  auxiliary  arm,  mechanically  connected  to  and  operating 
In  unison  with  the  arm  of  a  home  signal,  the  auxiliary  arm 
being  so  placed  that  when  the  signal  is  in  the  stop  position  a 
train  cannot  pass  without  breaking  against  it  a  glass  tube 


Fig.  668.     Model  "2- A"   Signal.     Arm  at  Stop. 

The  line  is  paralleled  by  a  telephone  system,  and  all  motor 
cars  are  equipped  with  a  telephone.  In  case  a  train  crew  finds 
a  signal  set  against  them,  they  can  get  into  communication 
with  a  dispatcher  by  plugging  into  the  telephone  jack  at  any 


Fig.  669.     Automatic 

Stop     Tube     Shown 

in  Place  on  Top 

of  Car  in  Figs. 

667-668. 


Fig.    670.     Track    Feed 
Location.      Resistance 
Grids    Mounted   Be- 
low  Transformer.- 


Fig.  671.     Location   Showing  Method 

of  Installation  of  Transformer, 

Relay  and  Grid  Boxes  and 

Reactance  Bonds. 


mounted  on   the  roof  of  the  motor  car.     The  breaking  of  this 
tube,    which    is    directly    connected    to    the    train    line,    reduces 
the  air  pressure,  giving  a  service  application  of  the  brakes.     The 
brakes,    having   been    so    set,   can   only   be   released   by   the   re- 
placement of  the  broken  tube ;   a  limited  supply  of  and  strict 
accounting  for   these   tubes   form   the   most   effective   check   on 
the   observance   of  signals.     To   provide  for  the  necessity  of  a 


signal  location  and  so  get  the  necessary  orders  to  proceed  or 
wait,  as  the  case  may  be.  During  a  period  shortly  after  the 
installation  of  the  signal  system,  when  considerable  trouble 
was  experienced  with  the  telophone  line,  it  was  found  that  the 
train  crews  were  able  to  maintain  their  schedules  and  operate 
their  trains  with  perfect  safety,  using  the  block  signals  as  their  ' 
only  guide. 


Figs.  672-674 


BLOCK   SIGNALS. 


SAX    FRA.VCISCO,    OAKLAND    &    SAN    JOSE    CONSOLIDATED   RAILWAY 

(THE  KEY  ROUTE). 

The  San  Francisco,  Oakland  and  San  Jose  Consolidated 
Railway  operates  between  Oakland,  Berkeley  and  Fiedmcnt, 
connecting  with  ferry  service  to  and  from  San  Francisco  by 
running  over  a  double  track  line  to  the  end  of  a  pier  extend- 
ing three  miles  into  San  Francisco  Bay  from  Oakland.  The 
traffic  is  intermittent  in  character,  four  or  five  trains  leaving 


Fig.  672.     Model  "2-A"  A.  C.  Signals  Mounted  on 
Trolley  Poles.     Key  Route. 

a  few  seconds  apart  from  the  pier  terminal  shortly  after  the 
arrival  of  each  ferry.  The  trains,  which  operate  on  GOO  volts 
direct  current,  are  made  up  of  from  four  to  eight  cars,  multi- 
ple unit  control  being  used.  Running  from  the  pier  terminus 
to  the  mainland,  the  trains  accelerate  until  they  reach  a  speed 
of  about  35  miles  per  hour,  whereas,  in  running  in  the  other 
direction,  the  speed  is  maintained  approximately  at  35  miles 
for  the  whole  distance.  Over  the  four  miles  of  road  from  the 
pier  terminal  to  the  junction  of  the  lines  leading  to  I'ied- 


slgnal  transmission  line.  This  is  stepped  down  at  track  feed 
and  signal  location  by  Model  H  transformers  to  the  various 
voltages  required  for  the  operation  of  the  signal  system,  but 
10  k.  w.  being  required  for  the  entire  installation,  consist- 
ing of  75  signals  with  their  controlling  devices  and  track  cir- 
cuits. Signal  transformers  and  relay  boxes  are  located  on 
the  center  poles  which  support  the  trolley  wires,  connections 
between  transformers  and  relay  boxes  and  between  relay  boxes 
and  signal  mechanisms  being  made  through  lead-covered  cables. 
This  is  necessary  as  a  protection  against  the  salt  spray,  which 
at  times  reaches  the  deck  of  the  pier.  Lead-covered  wire  is 
also  used  between  the  relay  boxes  and  the  rails. 

On  account  of  the  fact  that  a  headway  of  45  seconds  is 
maintained,  the  track  circuits  are  so  short  thai  it  was  found 
economical  to  use  single  rail  track  circuits,  the  continuous  rail 
being  supplemented  by  a  1,000,000'  circular  mil  copper  con- 
ductor to  assist  in  carrying  the  return  propulsion  current. 
The  track  relays  are  of  the  General  Railway  Signal  Co.'s  Model 
1  polyphase  type,  equipped  with  four  front  and  four  back 
contacts. 

The  signals  are  the  G.  R.  S.  Model  2  A,  operating  on  55-volt 
alternating  current.  The  mechanisms  are  controlled  directly 
over  the  line  without  the  intervention  of  a  line  relay,  taking 
the  45-deg.  position  through  the  track  section  immediately  ahead 
of  the  signal,  and  the  90-deg.  position  through  the  signal  In 
advance,  at  45  to  90  deg. 

The  automatic  stop  feature  consists  of  a  metal  arm  supported 
at  a  height  .slightly  above  the  car  and  operated  by  the  signal 


Fig.  673.     Model  "2-A"  A.  C.  Bridge  Signals. 
Key  Route. 

mechanism,  this  arm,  whenever  the  signal  is  in  the  stop 
position,  engaging  the  trip  arm  of  a  specially  designed  valve 
mounted  on  the  roof  of  the  motor  car.  The  tripping  of  this 
valve  is  designed  to  reduce  the  pressure  on  the  train  line, 
thereby  giving  a  service  application  of  the  brakes.  The  valve 
is  restored  to  its  normal  position  by  the  reduction  of  pressure 
in  the  train  line  to  a  predetermined  amount  by  the  use  of 
the  motorman's  b"ake  controller.  The  arrangement  is  such 
ar;  to  give  the  proper  application  of  air  through  the  brakes, 


Fig.  674.     Typical  Circuits  S.  F.  O.  &  S.  J.  C.  Ry. 


mont  and  Berkeley,  signals  have  been  installed  of  the  three- 
position,  upper  quadrant  type,  being  so  located  as  to  permit 
the  trains  to  operate  under  a  headway  of  45  seconds  at  the 
speeds  encountered  on  the  various  parts  of  the  line.  Automatic 
train  stops  of  the  overhead  type  provide  for  service  applications 
of  the  brakes  should  a  train  attempt  to  pass  a  signal  set  at 
stop.  This  installation  was  made  by  the  General  Signal  Com- 
pany. 

Motor   generator   sets,    located   at   one   of   the    traction    power 
houses,   furnish  1,100-volt,    25-cycle   alternating   current   to   the 


irrespective  of  how  the  motorman  may  manipulate  his  con- 
troller either  to  charge  or  discharge  the  train  line.  When 
running  against  traffic,  the  trip  arm,  after  engaging  the  first 
stop  arm,  is  arranged  to  be  held  down  in  the  reverse  position 
until  released  by  reducing  the  air  pressure  to  the  predetermined 
point  referred  to  above.  Arrangements  are  provided  whereby 
the  trainman  can  "key-by"  if  it  becomes  necessary  to  pass  a 
semaphore  in  the  stop  position.  This  is  accomplished  through 
unlocking  the  stop  mechanism  and  holding  up  the  stop  arm 
until  the  train  has  passed  by.  The  key  cannot  be  removed 


BLOCK   SIGNALS. 


Fig.  675 


from  the  lock  until  the  stop  arm  has  been  lowered  to  the 
full  stop  position  again,  so  that  it  will  set  the  trip  and  operate 
the  air  valves  on  the  cars  of  the  following  train. 

Because  of  the  foggy  weather  encountered  during  certain  por- 
tions of  the  year  and  the  severe  traffic  conditions  imposed  on 
the  road,  the  train  schedules  suffered  not  infrequently  before 
the  installation  of  the  signal  system.  The  installation  was 
made  only  after  a  close  study  of  the  operating  conditions,  and, 
being  based  on  the  results  of  careful  tests  as  to  braking  dis- 
tances, speeds  at  different  points,  etc.,  it  has  placed  the  road 
in  a  position  to  operate  its  trains  with  facility  and  safety  under 
the  worst  weather  conditions  and  during  the  periods  of  heaviest 
traffic. 


INTERBOROOGH    RAPID    TRANSIT    COMPANY'S    SUBWAY    DIVISION. 

Th«  arrangement  of  block  signals  installed  on  the  Subway  Di- 
vision of  the  Interborough  Rapid  Transit  Company  ^consists  of 
the  automatic  overlapping  system  shown  in  Fig.  675,  applied 
to  the  two  middle  express  tracks  and  to  the  third  track  on 
the  west  side  branch.  This  third  track  is  placed  between  the 
two  local  tracks,  and  is  used  for  express  traffic  in  both  direc- 
tions. The  apparatus  used  differs  little  in  general  principle 
from  that  employed  in  earlier  automatic  systems  of  block 
signaling,  the  substitution  of  alternating  current  in  place  of 
battery  current  for  the  track  circuit,  and  the  necessary  alter- 


at  each  block  by  a  double-secondary  oil  transformer,  one  coil 
of  which  feeds  the  track  circuit  and  the  other  the  signal-lamp 
circuit.  The  magnet-control  apparatus,  which  is  used  for 
operating  the  controlling  air  valves  for  the  signal  cylinders, 
receives  current  from  a  storage-battery  main  which  also  runs 
the  length  of  the  subway.  This  main  is  fed  by  several  sets 
of  16-volt  storage  batteries  in  duplicate,  which  batteries  are 
located  at  the  various  interlocking  towers  and  are  charged 
by  motor  generators. 

In  Fig.  685  is  shown  the  arrangement  of  the  apparatus  in- 
stalled at  a  block-signal  location.  It  consists  of  the  block 
signal,  the  transformer,  a  case  for  the  track-circuit  instru- 
ments and  the  automatic  stop  valve  box.  The  transformer 
takes  current  from  the  500-volt  main  through  three-amp, 
enclosed  fuses  to  the  primary  coil ;  its  secondary  contains 
two  coils,  one  of  which  delivers  current  at  50  volts  for  use 
in  the  four  c.  p.  incandescent  lamps  used  in  the  signal, 
while  the  other  coil  delivers  current  at  the  lower  voltage  (10 
volts)  for  use  in  the  track  circuit.  The  leads  to  the  track  cir- 
cuits pass  down  the  instrument  case  and  thence  to  the  rail  con- 
nections at  the  exit  end  of  the  block ;  in  the  instrument  case 
they  pass  through  non-inductive  grid-resistances  of  one  ohm, 
which  serve  to  prevent  any  large  amount  of  current  from 
flowing  through  these  circuits  in  case  of  abnormal  disturbing 
conditions  in  the  propulsion  return  current,  and  also  prevent 


500   VOLTS    A,C.  (PRIMARY)  MAINS 


RAILS 


STOP 


u/t  controllers  shown 
Home  "  -Slide 


20  VOLTS  D.C  (STORAGE  FED)       BLOCK  CIRCUIT  MAINS 


COMMON 

Return 

Fig.  675.     Diagram  of  Signal  Control  Circuits.    Interborough   Rapid   Transit   Company. 


nating  current  auxiliary  apparatus,  constituting  the  principal 
change.  In  detail  of  application  to  the  peculiar  requirements 
under  subway  conditions,  however,  the  system  embodies  many 
radical  features. 

In  Fig.  675  is  shown  a  diagram  of  the  block  signal  and 
automatic  train  stop  circuits  as  used  in  connection  with  the 
overlapping  feature  of  this  system. 

In  this  system  of  signaling  one  of  the  running  rails  of  each 
track  Is  insulated  from  the  propulsion-current  return  system 
and  is  devoted  to  signal  purposes.  Thus,  the  other  rail  per- 
forms the  function  of  serving  simultaneously  as  conductor  for 
the  direct-current  return  for  the  propulsion  system,  as  well 
as  that  of  one  of  the  conductors  for  the  alternating-current 
track  circuit  for  controlling  the  signals.  The  current  is  fed 
into  each  block  at  the  end  from  which  the  passing  train  leaves 
It,  the  connections  to  the  signal-control  apparatus  being  made 
from  the  opposite,  or  entering,  end  of  the  block,  as  shown  in 
the  circuit  diagram.  The  track  connections  at  the  signal 
end  of  the  block  lead  from  the  track  circuit  to  the  alter- 
nating-current signal-control  relay,  which  operates  secondary 
connections  in  the  various  circuits  of  the  signaling  system. 
This  relay  operates  double  contacts,  so  that  when  the  block 
is  clear  and  current  is  thus  passing  through  it,  two  separate 
circuits  are  closed ;  one  of  these  is  the  circuit  leading  to  the 
automatic  train  stop  at  the  entrance  to  the  block  in  the  rear. 

The  distant,  or  caution,  signals  are  operated  by  an  auxiliary 
circuit  as  the  result  of  the  setting  of  the  home  signal.  When 
the  home  signal  of  a  block  is  clear,  current  passes  through 
the  control  mechanism  of  the  distant  signal  of  the  preceding 
block,  thus  holding  it  clear  also.  When  the  home  signal  is 
changed  to  the  stop  position  the  current  flowing  in  the  auxiliary 
circuit  is  interrupted  by  a  circuit  controller  on  the  home 
signal,  which  causes  the  distant  signal  to  indicate  caution. 

The  alternating  current  for  the  track  circuits  is  supplied 
by  high-voltage  alternating-current  mains  which  run  the  entire 
length  of  the  tunnel.  These  deliver  current  to  the  signal 
blocks  at  600  volts  potential,  from  which  it  is  stepped  down 


an  excessive  alternating  current  passing  from  the  transformer 
when  short-circuited  by  the  presence  of  a  train  in  the  track 
circuit  which  it  feeds. 

The  alterating-current  track  relay  is  shown  in  Figs.  680-684. 
The  principle  of  operation  involved  is  that  of  the  action  of 
an  alternating-current  field  upon  a  slotted  metallic  (non- 
magnetic) vane,  which  is  caused  to  move  in  such  a  way  as  to 
close  the  two  circuit  contacts.  The  alternating-current  field 
is  supplied  by  a  magnet  of  laminated  field-core  construction, 
with  the  field  coils  arranged  very  close  to  the  pole  faces. 
The  vane,  which  is  of  aluminum,  is  pivoted  in  a  vertical 
position  on  jewel  bearings.  The  upper  half  of  each  pole  piece  is 
enclosed  by  a  copper  ferrule  set  into  a  notch.  The  ferrule 
is  so  arranged  that  half  the  lines  of  force  in  the  field  must 
pass  through  it.  Any  change  in  the  number  of  lines  of  force 
through  the  ferrule  will  set  up  an  electromotive  force  in  the 
ferrule  acting  to  produce  a  current.  The  direction  of  this 
current  will  be  opposite  to  that  producing  the  change  in  the 
field  and  will  itself  tend  to  produce  lines  of  force  in  opposi- 
tion to  the  field.  In  other  words,  changes  from  zero  lines  of 
force  to  maximum  and  back  to  zero  will  be  retarded  in  the 
"shaded"  or  ferrule-enclosed  half  of  the  field.  This  will 
cause  the  magnetic  flux  to  shift  from  the  lower  to  the  upper 
portion  of  the  field  at  each  reversal  of  polarity.  Now  currents 
are  generated  about  the  slots  in  the  vane  by  the  field  flux 
the  same  as  in  the1  ferrule.  These  currents  will  produce  fields 
of  their  own  opposite  to  the  main  field,  and  will  act  against 
the  main  field  and  be  repelled  by  it  in  the  same  manner  as 
like  magnetic  poles.  But  the  shifting  flux  in  the  main 
field  due  to  the  ferrules  is  constantly  moving  upward.  There- 
fore the  vane  is  raised.  The  action  is  similar  to  that  between 
fields  and  squirrel-cage  armature  in  a  polyphase  induction 
motor. 

The  track  relay  and  associated  apparatus  are  housed  in  a 
cast-iron  instrument  case  of  water-tight  construction,  as  shown 
in  Fig.  685.  This  consists  of  two  sections,  the  lower  part 
containing  the  relay  and  connections,  and  the  upper  part  the 


Figs.  676-679 


BLOCK   SIGNALS. 


grid-resistances,    Figs.    678-679,    which    are    connected,    one    in  from   which   connections   are   made   to   the  distant  signal   rnech- 

series    with    the    transformer    supplying    alternating    current    to  anism  in  the  preceding  block  and  to  the  automatic  stop,  as  well 

the  track  circuit,  and  the  other  in  series  with  the  track  relay.  as    to    the   storage-battery   mains    for   the   direct-current    supply 

The   impedance   coil,   Fig.    677,   is   connected   in   multiple  with  for  the  signal   mechanism.     Four   conductors   lead   out   to   make 


Fig.  677.     Impedance  Coil  Used  on  Single 

Rail   Alternating   Current  Track 

Circuit. 


Fig.  6/6.     Track  Transformer  Coils  and  Core.    Union  Switch  & 
Signal  Co. 


Figs.   678-679.     Non-inductive   Resistance   Grids  Used  in  A.  C.  Track  Circuits, 
the    track    relay    and    shunts    out    any    propulsion    current    that        the   necessary    connections   with    the   rails   on   each    side   of   the 


might  have  a  tendency  to  pass  through  it. 
A      seven-conductor     cable      leads     to      the      signal     nearby, 


insulated  joints. 

The    signal     (Figs.     690     and     691-692)     consists    of    a    ver- 


whlle    another   seven-conductor    cable    leads    to    a    junction    box       tical   iron  case  fitted  with   two   white   lenses,   the   upper  being 


n6 


BLOCK   SIGNALS. 


Figs.  680-684 


Fig.    680.     Single    Phase    Alternatin 
Current   Track   Relay. 


Figs.  681-684.     Details  of  Single  Phase  A.  C.  Track    Relay.    Union  Switch  &  Signal   Company. 


Figs.  685-688 


BLOCK   SIGNALS. 


117 


Fig.   685.     Automatic    Signal,   Transformer,    Instrument  Case    and    Automatic    Train    Stop.     Interborough    Rapid 

Transit   Company. 


STOP  DOWN 


»-!    STOP  UP 


MINIMUM  DISTANCE.TRAIN  STOPPED 


-OVERLAP 


B 


CAUTION  DISTANCE  2ND  TRAIN  UNDER  CAUTION 


SECOND  TRAIN 


SIGNAL   AT    DANGER 

2 


SIGNAL  AT  CAUTION 

3 


SIGNAL  AT  CLEAR 

4 


-OLE  AR  PI  STANCE.  2ND  TRAIN  RUNNING  WITH  CLEAR  3IGNAL- 


Figs.  686-688.     Diagram  of  Overlapping  Block  Signal.     Interborough  Rapid  Transit  Company. 


n8 


BLOCK   SIGNALS. 


Figs.  689-692 


the  home  signal  and  the  lower  the  distant.  Suitable  colored 
glasses  are  mounted  in  slides,  which  are  operated  by  pneumatic 
cylinders.  Home  signals  show  a  red  light  for  the  stop  in- 
dication. Distant  signals  show  a  yellow  light  for  the  caution 
indication.  All  signals  show  a  green  light  for  the  "proceed" 
or  clear  indication.  A  positive  indication  has  been  provided 
for,  as  an  auxiliary  to  the  color  indications,  in  the  form  of  a 
small  arm  immediately  beneath,  the  lenses.  The  small  arm  ap- 
pears in  a  horizontal  position  when  a  stop  or  caution  signal 
is  displayed,  and  at  an  inclination  of  60  degs.  when  clear,  this 
being  provided  in  addition  to  the  color  indications  for  use 
in  case  of  failure  of  the  lamps  for  the  color  indications.  The 


exhibit  the  green  color  for  the  clear  indication  only  when 
held  in  its  upper  position  by  the  pneumatic  cylinder ;  In  this 
way  any  accident  to  the  apparatus,  cutting  off  the  compressed 
air,  will  permit  the  slides  to  drop  and  indicate  red  or  stop. 
The  signals  which  are  used  on  the  exterior  elevated  portions 
of  the  system  are  of  the  semaphore  type,  although  operated 
similarly  to  those  in  the  subway  sections  and  by  a  similar 
construction  of  mechanism. 

Automatic  train  stops  are  provided  and  arranged  so  as  to 
act  at  the  second  stop  signal  in  the  rear  (see  Figs.  675,  and 
686-688).  That  is  to  say,  the  train  stop  does  not  operate 
as  soon  as  the  signal,  at  which  it  is  situated,  goes  to  the 


_ 


UJ    UJ 

in  SE 


. 

2 


SECTION   G-H. 


MAGNET. 
CIRCUIT  BREAKER. 


Figs.  689-690.    Sectional  View  of  Electro-Pneumatic  Slide 

Signal   Mechanism  and  Case.     Interborough 

Rapid  Transit  Company. 

-•^v 

blade  ha?  •£'*"/  "'-.'-extending  within  the  case  and   ending  in   a 


pin  whi<  a  >  jVtjs  in  an  inclined  groove  in  such  a  way  as  to 
turn  the  ?*pde  through  an  angle  of  60  degs.  as  the  slide  passes 
from  upp^iy  to  lower  position.  The  signal  consists  of  two 
sections  •  'tile  upper  and  rear  portion  contains  the  lenses  and 
position  indicator  for  the  home  signal.  The  front  and  lower 
portion  of  the  case  contains  the  distant  signal  mechanism. 
Each  lens  is  constantly  lighted  by  two  4  c.  p.  incandes- 
cent lamps  at  the  rear,  the  two  lamps  being  connected  in  parallel 
in  order  that  one  may  be  always  lighted  even  if  the  other 
burns  out.  The  pneumatic  cylinders,  which  operate  the  heavy 
verJcal  sliding  frames  carrying  the  colored  glass  for  the  signal 
indications,  are  located  in  the  base  of  the  case.  The  slides 


Figs.  691-692.     Double  Electro-Pneumatic  Slide  Signal. 

Interborough  Rapid  Transit 

Company. 

stop  position,  but  stays  down  until  the  train  enters  the 
overlap  section,  when  it  comes  up  in  place  to  "trip"  a  train, 
should  one  run  past  the  red  signal.  This  arrangement  is 
necessary  in  order  to  permit  every  car  of  a  train  to  be  fit- 
ted with  the  automatic  brake  valve,  and  at  the  same  time 
not  be  "tripped"  by  the  forward  portion  of  the  train  enter- 
ing the  block.  The  signals  are  so  placed  that,  at  maximum 
speed,  a  train  would  be  brought  to  a  stop  by  the  automatic 
application  of  the  brakes  before  it  could  reach  a  preceding 
train. 

This  arrangement  of  apparatus,  but  without  the  overlap  and 
train  stops,  was  first  used  on  the  North  Shore  Railroad  of 
California,  i 


Figs.  693-696 


BLOCK   SIGNALS. 


119 


ELECTRIFIED    LINES    OF   THE   LONG    ISLAND   RAILROAD. 

In  the  electrification  of  this  road  a  third  rail  is  used  for 
delivery  of  the  propulsion  current  and  both  of  the  running 
rails  for  its  return.  Direct  current  is  used  for  propulsion  and 
alternating  current  for  signal  track  circuits,  with  inductive 
rail  bonds,  installed  at  the  insulated  joints  separating  dif- 
ferent track  sections,  which  give  a  free  path  for  the  pro- 
pulsion current.  Automatic  signals  are  of  the  motor  type 
(Fig.  538),  with  the  exception  of  the  two  subways,  where  an 
electric  light  signal  is  used  (Figs.  693-695).  The  lights  in 
this  signal  are  controlled  by  alternating-current  line  relays, 


WEST    JERSEY    &    SEASHORE    RAILROAD. 

The  automatic  electro-pneumatic  signals  are  controlled  by 
alternating-current  track  circuits  flowing  through  the  running 
rails,  which  also  convey  the  return  direct  current  of  the  pro- 
pulsion system ;  and  the  air  compressors  are  run  by  electric 
motors  supplied  with  current  from  the  third  rail. 

Fig.  697  is  a  diagram  of  a  typical  track  circuit.  In  con- 
sequence of  the  difficulty  of  conveying  alternating  current 
through  the  rails  of  the  track  under  the  existing  conditions, 
the  track  circuit  is  conveyed  from  the  transformer  to  the 
rails  in  the  middle  of  the  block  section,  as  shown.  Thus,  in  a 


O 


Back  View,  Cover  Removed.  Side  View,  Section  A-B.  Front  View. 

Figs.  693-695.     Double  Electric  Light  Subway  Signals.     Long  Island  Railroad. 


which  in  turn  are  controlled  by  the  track  relays  (Figs.  680-684). 

On  seven  miles  of  double  track,  which  has  also  been  equipped 
with  alternating-current  track  circuits  for  the  signals,  the 
inductive  rail  bond  is  not  used,  as  this  part  of  the  road  is 
not  worked  by  electric  traction.  The  alternating-current  track 
circuit,  nevertheless,  was  installed  here  for  the  operation  of 
the  existing  system  of  automatic  signals  in  this  territory,  on 
account  of  a  third  track  on  this  division,  which  is  electrified, 
and  runs  parallel  with  the  two  main  tracks. 

The  length  of  the  sections  ranges  from  1,000  to  1,200  ft,  with 
the  transformers  (Fig.  676)  connected  at  one  end  of  the  sec- 
tion, and  from  1,300  ft.  to  2,800  ft.,  with  the  transformers 
connected  in  intermediate  positions. 

The  motor  signals  used  are  of  the  Union  Switch  &  Signal 
Co.'s  standard  Style  B  type  (Fig.  538).  Current  for  the  motors 
and  the  line  relays  is  taken  from  two  sets  of  storage  batteries 
installed  at  every  pair  of  signals  and  so  arranged  that  one 
set  is  being  charged  while  the  other  set  is  discharging.  The 
charging  current  is  taken  from  the  third  rail  at  650  volts 
through  a  high  resistance  so  proportioned  that  just  the  neces- 
sary current  flows  into  the  batteries.  A  100-kilowatt  trans- 
former supplies  the  high-tension  mains  with  the  current  at  a 
potential  of  2,200  volts  and  a  frequency  of  25  cycles. 

These  mains  are  carried  underground  in  a  lead  cable  for 
about  eight  miles,  and  on  the  high-tension  transmission  pole 
line  for  the  rest  of  the  system.  From  the  alternating-current 
main  taps  are  brought  into  the  primary  transformers  where 
the  potential  is  reduced  to  55  volts.  This  is  in  turn  reduced 
in  another  set  of  transformers,  called  track  transformers,  to 
from  two  to  six  volts,  as  the  conditions  of  the  different  track 
sections  require.  In  the  subways  the  lights  in  the  signals 
and  all  line  relays  are  also  supplied  from  the  55-volt  side  of 
the  primary  transformers. 

In  the  subway  and  on  the  elevated  structure,  full  block 
overlaps  are  used. 


Fig.  696.     Alternating  Current  Relay,  Wire  Wound 
Armature.     West  Jersey  &  Seashore  Railroad. 


I2O 


BLOCK   SIGNALS. 


Figs.  697-698 


signal  section  4,000  ft.  long  the  current  has  to  pass  through 
only  2,000  ft.  of  track.  The  track  relay  (Fig.  696)  is  con- 
trolled not  only  by  the  track  circuit,  but  also  by  the  current 
through  the  line  wires,  as  shown  in  the  lower  part  of  the 
drawing. 

On  the  West  Jersey  &  Seashore,  the  propulsion  current  con- 
ditions were  as  follows  :  Maximum  capacity  of  each  sub-station 
in  amperes,  3,500  to  7,000,  ultimate ;  normal  average  output 
of  each  sub-station  in  amperes,  1,500  ;  number  of  amperes  to 


tainer    can,    without    risk    to    himself,    open    the    line    and    limit 
the    trouble   to    the   territory    in   which    it    exists. 


NEW    YORK,    NEW    HAVEN    &    HARTFORD. 

Fig.  699  shows  the  type  of  automatic  signals  installed  by 
the  Union  Switch  &  Signal  Co.  on  a  section  of  the  New 
York,  New  Haven  &  Hartford  Railroad.  This  section  is  used 
both  for  steam  and  electric  traction,  the  electric  cars  taking 
direct  current  from  an  overhead  trolley  wire.  Through  the 


A.  C.  Mains. 

(AW 

Track   Transformer. 

1 
c        InOuct/ve  Bonds. 

^x^x-^-^      /ndvctive  Bonds 
'  f 

353 

—                  M- 

i  i 

A 

i 

V«J         ftefa/Exctt/ny 
*""*         Transformer. 


Fig.  697.     Diagram  of  Transformer  and   Track  Circuit  Connections.    West  Jersey  &  Seashore  Railroad. 


start  trains  on  a  level,  500  to  1,200  amperes  per  car  ;  number 
of  cars  per  train,   six. 

The  inductive  bonds  and  their  connections  which  have  been 
put  in  to  meet  these  conditions  introduce  in  each  rail  a 
resistance  per  block  equivalent  to  only  about  40  ft.  of  100-lb. 
rail,  so  that  in  the  4,000-ft.  blocks  the  increase  in  the  resist- 
ance of  that  part  of  the  propulsion  return  system  formed  by 
the  rails  is  only  one  per  cent.  The  relays  are  of  the  motor 
type,  the  armature  and  the  field  both  having  coils  which  are 
energized  when  the  current  flows.  The  field  is  supplied  by  the 
25-cycle  current  taken  from  the  rails  at  the  entering  end  of 
the  block.  The  armature  is  supplied  by  the  current  from  the 
leaving  end  of  the  block  and  the  current,  which  is  taken  from 
the  rails  at  the  leaving  end,  is  stepped  up  for  transmission  by 
a  six-watt  transformer.  The  transformers  are  not  injuriously 
affected  by  being  short-circuited  by  trains  standing  opposite 


entire  length  of  the  signaled  section  there  is  a  10,000-volt, 
three-phase,  60-cycle  commercial  line  giving  a  reliable  24- 
hour  service.  From  this  supply  current  is  procured  for  the 
signal  system,  the  connection  being  made  through  step-down 
transformers.  The  transformers  are  connected  to  one  phase 
of  the  high  potential  line,  stepping  the  current  down  from 
10,000  volts  to  2,200  volts  and  connecting  through  oil  switches 
to  the  signal  transmission  lines  which  extend  the  entire  length 
of  the  signal  system.  From  this  2,200-volt,  60-cycle  line,  cur- 
rent is  obtained  through  transformers  for  the  various  signal 
requirements.  The  automatic  signals  have  home  and  distant 
arms,  pivoted  near  the  center  and  mounted  upon  the  same 
post.  The  eastbound  and  the  westbound  signals  are  placed 
nearly  opposite  each  other,  but  are  staggered  sufficiently  to 
avoid  putting  a  signal  where  a  trolley  pole  will  hide  it  from 
the  engineman.  The  blade  grip  castings  are  designed  to  per- 


A  C.  SIGNAL  MAINS 


Fig.  698.     Arrangement  of  Control  Circuits  for  Normal  Clear  Alternating  Current  Automatic  Block  Signals. 

New  York,  New  Haven  &  Hartford. 


them.  Their  primaries  are  fed  by  the  1,100-volt,  25-cycle  sig- 
nal mains  running  from  the  sub-stations.  At  each  sub-station 
there  is  a  switchboard  for  handling  the  signaling  current,  which 
is  stepped  down  to  the  signal  line  voltage  from  one  leg  of  the 
propulsion  mains.  The  switchboard  is  supplied  with  indicating 
instruments  for  showing  the  voltage  of  the  signal  mains  and 
of  the  current  going  in  either  direction.  Recording  watt- 
meters are  provided  to  determine  how  much  power  is  used  by 
the  track  circuits.  The  arrangement  of  oil  switches  is  such 
that  the  signal  mains  can  be  disconnected  on  either  side  of 
the  sub-station  or  made  continuous  atfd  disconnected  from  the 
sub-station. 

Oil   line   switches   are   fixed   in  the  signal   mains  midway  be- 
tween the  sub-stations,  so  that  in  case  of  line  trouble  a  main- 


mit  the  arm  to  extend  to  the  left  of  the  post  for  the  reason 
that  the  trolley  poles  would  obstruct  the  view  of  the  signal 
if  it  extended  only  to  the  right. 

The  motor  signals  have  double-case  bases  and  rest  on  con- 
crete foundations.  The  upper  case  contains  the  signal  mech- 
anism, which  is  operated  by  a  110-volt  single-phase  induction 
motor.  The  motor  has  sufficient  torque  at  starting  to  start 
under  load  from  any  point  in  the  arc  through  which  the  signal 
travels.  The  time  required  to  clear  both  the  home  and  the 
distant  arms  is  five  seconds.  The  lower  case  contains  track 
relays,  line  relays,  controlling  switches,  fuses  and  lightning  ar- 
resters. Duplicate  two-candle-power  incandescent  electric  lights 
are  used  in  the  lanterns.  Oil  founts  are  also  provided. 

At  each  signal  there  is  a  transformer  stepping  down  from  the 


Figs.  699-700 


BLOCK   SIGNALS. 


121 


2,200-volt  line  to  110  volts  to  supply  current  for  the  local 
signals  and  the  control  circuits  for  the  next  signals  in  the 
rear.  The  signal  control  line  extends  the  entire  length  of 
the  block  section,  taking  energy  at  the  outgoing  end  and 
looping  through  the  track  relays  and  switch  instruments. 

The  track  circuit  equipment  installed  is  designed  to  be  used 
with  a  propulsion  current  either  direct  or  alternating;  either 
550-voIt  direct  or  11,000-volt,  25-cycle,  single-phase  alternating. 
The  electric  railway  company  required  •  that  the  tracks  be 
cross  bonded  at  least  every  3,000  ft.,  thus  making  necessary 
a  cut  section  in  each  block.  Energy  is  supplied  to  the  tracks 
by  a  transformer  situated  in  the  middle  of  a  track  circuit 
section.  The  track  circuit  has  a  relay  at  each  end.  These  are 
"frequency"  relays,  that  is  to  say,  relays  which  respond  only 
to  alternating  currents  of  a  given  frequency.  These  control 
the  signal  circuits.  At  each  end  of  the  track  circuit  there 


Fig.  699.     Alternating  Current   Signal   Mechanism  and 
Relay  Case.     New  York,  New  Haven  &  Hartford. 

is  also  an  inductance  bond,  the  terminals  of  which  are  con- 
nected to  the  rails,  and  the  center  of  which  is  connected  to 
the  center  of  the  bond  of  the  next  track  circuit,  thus  forming 
a  metallic  connection  around  the  insulated  rail  joints  for  the 
return  propulsion  current.  This  center  connection  may  also 
be  used  for  cross-bond  connection  to  the  other  track. 

The  inductance  bonds  were  designed  to  carry  the  heavy  cur- 
rent necessary  with  direct-current  propulsion  and  also  were 
balanced  to  offer  the  least  possible  impedance  to  an  alternating 
propulsion  current.  In  fact,  if  the  external  track  return 
is  perfectly  balanced,  the  only  impedance  of  the  bonds  may  be 
said  to  be  ohmic.  The  frequency  relays  are  of  the  vane  type  and 
are  immune  to  a  direct  current  or  to  alternating  current  of 
25  cycles,  having  been  designed  to  operate  at  60  cycles.  The 
unbalancing  of  the  track,  therefore,  even  if  sufficient  to  throw 
a  heavy  current  through  the  frequency  relays,  would  not  re- 
sult in  a  false  clear  signal  indication.  This  system  will,  of 
course,  not  be  affected  by  any  fore'gn  trolley  current.  To  con- 


nect up  an  inductance  bond  to  a  track  with  "broken"  or 
"staggered"  joints,  it  is  necessary  either  to  cut  one  rail  of  the 
track  so  as  to  have  the  insulated  joint  near  the  bond,  or  to 
provide  a  conductor  from  the  bond  to  connect  with  the  track 
beyond  the  insulated  joint.  In  this  case  use  is  made  of  a  piece 
of  old  rail  about  15  ft.  long.  The  piece  of  steel  rail  is  better 
than  copper  because  it  costs  less  and  is  not  liable  to  be  stolen ; 
and  besides  this,  if  alternating  current  is  used  for  propulsion, 
the  iron  serves  to  restore  the  balance  of  the  inductance  of  the 
two  lines  of  rails,  which  with  one  side  15  ft.  shorter  than  the 
other,  would  be  unbalanced. 

Fig.    698    shows   a  diagram   of  typical    circuits   used   in  this 
installation. 


BOSTON*   ELEVATED   RAILROAD. 

Figs.  700-709  illustrate  the  automatic  block  signal  circuits 
and  apparatus  used  on  the  rapid  transit  lines  of  the  Boston 
Elevated  Railroad.  On  this  road  the  propulsion  system  uses 
direct  current  delivered  by  a  third  rail  and  returning  by  one 
of  the  running  rails  which  is  grounded  to  the  elevated  struc- 
ture, the  negative  terminals  of  the  propulsion  generators  being 
connected  to  the  grounded  rail.  The  other  running  rail,  desig- 
nated as  the  "block  rail"  in  Fig.  701,  is  given  up  exclusively 
to  signaling  purposes.  It  is  divided  into  sections  by  insulated 
joints,  each  section  constituting  one  side  of  a  "single  rail" 
track  circuit,  the  grounded  rail  being  a  common  conductor  for 
both  signal  and  propulsion  current. 

This  being  the  first  installation  where  it  was  attempted  to 
use  signal  track  circuits  together  with  propulsion  current  re- 
turn on  the  running  rails,  it  may  be  well  to  consider  the  fea- 
ture known  as  "drop  in  potential"  along  the  common  rail, 
caused  by  the  presence  of  the  propulsion  current. 

Fig.    704    illustrates    how    the    presence    of   two    trains    might 


Fig.    700.     Polarized    Track    Relay. 
Railroad. 


Boston    Elevated 


cause  a  difference  of  potential  across  the  relay  terminals. 
When  current  is  flowing  m  any  conductor  there  is  always  a 
difference  of  potential  between  any  two  points  on  that  conductor 
due  to  its  resistance.  V  represents  a  voltmeter  so  connected 
as  to  measure  the  potential  due  to  the  flow  of  return  pro- 
pulsion current  over  the  continuous  rail.  With  one  train  at 
the  leaving  end  of  the  block  and  another  approaching,  the  re- 
lay has  the  same  potential  across  its  terminals  as  that  meas 
ured  by  the  voltmeter,  for  wire  a  connects  on  side  at  the 
same  point  as  the  positive  lead  of  the  meter,  and  wire  6,  the 
insulated  rail,  and  the  wheels  and  axles  of  the  train  at  the 
right  connect  the  other  side  to  the  same  point  as  the  negative 
lead  of  the  meter.  Whether  or  not  an  ordinary  type  of  relay 
will  close  its  contacts  under  these  conditions  depends  on 
whether  or  not  the  voltage  at  which  it  is  adjusted  to  oper- 
ate is  greater  than  the  drop  of  potential  caused  by  the  return 
of  power  current  over  the  length  of  rail  measured  by  the 
length  of  the  block. 


122 


BLOCK   SIGNALS. 


Figs.  701-703 


However,  in  the  case  of  the  Boston  Elevated  Railroad,  the 
blocks  are  short  and  the  common  return  rail  is  grounded  at 
close  Intervals  to  the  structure,  which  has  a  copper  equivalent 
of  14,000,000  circular  mils.  These  conditions  make  it  per- 
missible to  use  a  relay  whose  voltage  adjustment  provides 
against  any  "return  drop"  which  may  occur. 

The  signals   are  of  the   electro-pneumatic  type   made   by   the 


the  mechanism  case  of  a  signal,  and  also  the  adjustable  re- 
sistance tubes  for  the  track  circuit  in  the  rear.  The  electro- 
pneumatic  valve  and  cylinder  which  operates  the  signal  are 
placed  on  the  back  side  of  the  partition,  as  shown  in  Fig.  701. 
The  relay  (Fig.  700)  is  operated  by  direct  current,  requiring 
a  potential  of  five  volts  at  its  terminals  to  "pick  up,"  and  is 
polarized ;  its  magnet  is  wound  to  50  ohms  resistance.  The 


Fig.   701.     Diagram   of  Automatic   Signal    Circuits   and  Apparatus.     Boston   Elevated  Railroad. 


Union  Switch  &  Signal  Co.,  and  operate  "normally  clear." 
Current  is  supplied  to  the  signal  system  from  100-volt  gen- 
erators by  the  main  "block  feed  wire"  (Fig.  701),  with  the 
grounded  rail  of  the  tracks  as  a  return.  It  is  to  be  noted 
that  the  negative  terminals  of  the  signal  generators  are  con- 
nected to  the  feed  wire  and  the  positive  terminals  to  the 


horizontal  armature  at  the  base  is  raised  by  the  large  50-ohm 
magnet,  when  energized,  irrespective  of  the  direction  of  the 
current.  The  link  extending  upward  connects  this  horizontal 
armature  to  a  phosphor-bronze  contact  plate  carrying  two 
heavy  carbon  blocks,  one  at  each  end,  which  lie  under  contact 
points  of  the  same  substance  mounted  above  them  and  properly 


Figs.    702-703.     Arrangement  of   Automatic   Signal   and   Train-Stop  Apparatus  on  Structure. 

Boston  Elevated  Railroad. 


grounded  rail.  An  adjustable  resistance  is  introduced  between 
the  feed  wire  and  the  block  rail  of  each  track  circuit,  which 
limits  the  flow  of  current  while  the  block  is  occupied  and 
prevents  the  shunting  of  one  track  circuit  from  affecting  any 
of  the  others.  The  track  relay  is  one  of  the  notable  features 
of  this  installation,  being  quite  a  departure  from  ordinary  prac- 
tice in  signal  work.  Figs.  705-706  show  this  relay  mounted  in 


insulated.  The  contact  plate  is  rigidly  secured  to  the  upper 
pole-piece  of  a  pair  of  smaller  magnets  mounted  transversely 
to  the  one  first  mentioned  and  pivoted  on  trunnions  formed 
upon  the  ends  of  the  upper  pole-piece.  The  lower  ends  of  these 
swinging  magnets  are  joined  by  the  lower  pole-piece,  which 
hangs  between  the  extended  cores  of  the  larger  magnet  and  is 
attracted  by  one  or  the  other,  according  to  its  polarity.  The 


Figs.  704-706 


BLOCK   SIGNALS. 


123 


swinging  magnets  are  wound  to  produce  like  poles  at  the 
same  ends,  hence  the  two  pole-pieces  joining  them  actually 
constitute  the  poles  of  one  double  magnet.  The  coils  of  the 
50-ohm  magnet  are  wound  in  the  usual  manner  and  included 
in  the  track  circuit,  being  energized  (when  the  block  is  un- 
occupied) by  current  from  the  signal  generator.  The  right- 
hand  contact  is  operated  by  motion  of  the  swinging  magnets. 

TROLLEY 


left.  But  as  soon  as  the  left-hand  contact  is  closed,  current 
passes  from  the  grounded  rail  through  the  resistance  lamp 
and  the  swinging  coils  to  the  feed  wire.  This  circuit,  energizing 
these  magnets,  causes  their  lower  pole-piece  to  swing  to  the 
right,  bending  the  contact  plate  and  closing  the  right-hand 
contact ;  this  latter  contact  completes  the  circuit  through  the 
signal  control  magnet  and  clears  the  signal.  It  will  be  seen 

OR  35?  RAIL 


TRACK  ff£i.AY 


704.     Diagram   Showing  Potential  at  Terminals  of  a   Track   Relay.     Due   to    Return    Propulsion    Current. 
(Reproduced  from  the  Proceedings  of  the  American  Institute  of  Electrical  Engineers.    Copyrighted  1907.) 


Suppose  the  relay  to  be  de-energized  by  the  presence  of  a 
train  in  the  block,  the  sequence  of  operation  in  closing  the 
relay  contacts  is  as  follows  :  As  soon  as  the  train  passes  out 
of  the  block  current  flows  from  the  positive  terminal  of  the 
signal  generator  along  the  grounded  rail  through  the  50-ohm 


that  there  is  a  mechanical  counter  effect  of  the  swinging  mag- 
net upon  the  work  performed  by  the  neutral  armature  which 
will  cause  the  latter  to  drop  in  response  to  a  very  slight  re- 
duction in  current. 
When  a   train  again   enters  the  block  it  shunts   the   50-ohm 


Fig.  705.     Relay,  Resistance  Tubes  and  Lamp  in  Signal          Fig.    706. 
Case.      Boston    Elevated    Railroad. 


Diagram    of   Signal    Control    Apparatus. 
Boston  Elevated  Railroad. 


coil  of  the  relay  at  the  signal  on  the  right  (Fig.  701)  along 
the  block  rail,  through  the  resistance  tube  at  the  signal  on 
the  left  and  back  over  the  main  feed  wire  to  the  negative 
terminal  of  the  generator.  This  picks  up  the  armature  at  the 
base  of  the  relay,  closes  the  left-hand  contact,  and  tends  me- 
chanically to  move  the  lower  pole  of  the  swinging  magnet  to  the 


coils  causing  the  lower  armature  to  drop  and  open  both  con- 
tacts. If  now,  while  the  train  is  in  the  block,  the  wheels 
should  make  poor  contact  on  the  grounded  rail  (on  account 
of  the  presence  of  sand  or  ice,  or  for  any  other  reason),  pro- 
pulsion current  might  flow  from  the  wheels  to  the  block  rail 
and  through  the  relay  to  the  grounded  rail.  This  would  pick 


124 


BLOCK   SIGNALS. 


Figs.  707-710 


up  the  neutral  armature,  but  in  this  case  the  polarity  of  the 
current  and  consequently  tLat  of  the  magnet  is  now  reversed, 
and  as  soon  as  the  left-hand  contact  closes  permitting  current 
to  pass  through  the  swinging  coils,  they  are  held  over  to  the 
left,  preventing  the  right-hand  contact  from  closing  and 


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Fig.  707.     Diagram  of  Transformer  and  Single  Phase 

Track  Relay  Connections,  East  Boston  Tunnel. 

Both  Running  Rails  Used  for  Propulsion 

Current  Return. 


Fig.    7 


Circuits   for    Control    of   Distant   Signal. 
Boston  Elevated  Railroad. 


keeping  the  signal  in  the  stop  position.  The  swinging  coil 
being  in  series  with  the  signal  magnet,  any  interruption  in  the 
circuit  which  might  tend  to  depolarize  the  relay  would  also 
result  in  the  signal  going  to  the  stop  position. 

Fig.  708  shows  the  circuit  used  for  control  of  a  distant 
signal. 

Figs.  702-703  show  how  the  signal  is  set  in  relation  to  the 
track  on  the  elevated  structure,  and  also  illustrate  one  method 
of  connecting  the  automatic  train  stop,  which  is  a  feature  of 


this  installation.  Fig.  709  gives  a  view  of  the  tunnel  signal 
and  train-stop  used  in  the  subway.  This  signal  has  no  blade, 
the  light  being  its  only  indication.  The  train-stop  is  oper- 
ated by  a  separate  cylinder  instead  of  by  a  rocker-shaft  as 
on  the  structure. 


INTERBOROUGH    RAPID   TRANSIT   COMPANY'S    ELEVATED   LINES. 

The  Interborough  Rapid  Transit  Co.  has  in  service  on 
the  elevated  lines  semaphore  block  signals,  operated  by  sole- 
noids energized  by  current  taken  from  the  third  rail.  The 
current  for  the  track  circuit  is  also  obtained  from  the  third 
rail.  The  apparatus  and  circuits  for  a  typical  block  section 
are  shown  diagrammatically  in  Fig.  712.  Only  one  of  the 
track  rails  is  insulated  for  the  block  section,  which  varies  in 
length  for  the  different  locations  where  the  signals  are  used. 
At  the  outgoing  end  of  the  block,  the  third  rail  is  connected 
through  a  fuse  to  a  resistance  plate  having  two  taps  at  the 
upper  end,  one  of  which  is  connected  to  the  insulated  track 


Fig.    709.     Tunnel    Signal    and    Automatic    Train    Stop. 
Boston   Elevated   Railroad. 


Fig.    7K).     Solenoid    Semaphore.      Interborough    Rapid 
Transit    Company. 

rail  and  the  other  to  the  opposite  or  common  track  rail,  which 
is  grounded  for  the  return  power  circuit.  The  resistance  is 
adjusted  to  give  a  difference  of  potential  between  the  two- 
track  rails  of  10  volts.  At  the  entering  end  of  the  block,  the 
two-track  rails  are  connected  together  through  a  two-point  track 
relay,  which  is  wound  to  pick  up  at  three  volts.  The  normal 
difference  of  potential  of  10  volts  is  sufficient  to  care  for 
the  widest  variations  in  voltage  of  the  third  rail  current  passing 
through  the  resistance  plate. 

At  the  signal,  a  tap  from  the  third  rail  connects  to  a  bus 
bar  on  which  are  three  snap  switches,  one  in  the  solenoid 
relay  circuit,  one  in  the  main  signal  solenoid  circuit,  and  one 
in  the  signal  lamp  circuit.  When  no  train  is  in  the  block, 
the  track  relay  is  energized  and  its  two  contacts  are  closed. 
Current  from  the  third  rail  passes  through  switch  1,  resist- 
ance, track  relay,  armature,  solenoid  relay  coil  and  thence  to 
common  rail  or  ground.  Current  also  flows  through  switch  2, 
armature  of  solenoid  relay  and'  resistance  of  3,000  ohms  to 
solenoid  coil  and  thence  to  ground,  holding  the  signal  in  the 
proceed  position. 


Figs.  711-713 


BLOCK   SIGNALS. 


125 


When  a  train  enters  the  block,  the  track  relay  opens,  re- 
leasing the  spring-actuated  quick-break  solenoid  relay,  whose 
armature  controls  600  volts.  This  breaks  the  solenoid  circuit 
and  permits  the  signal  arm  to  go  to  stop  by  gravity.  An  oil 
dash  pot  is  provided  to  cushion  the  shock  of  the  moving  arm. 
When  the  train  passes  out  of  the  block  the  track  relay  picks 
up,  causing  the  solenoid  relay  in  turn  to  pick  up.  Current 


Fig.  711.     View  of  Mechanism  of  Solenoid  Semaphore 
Signal.     Interborough    Rapid   Transit   Company. 


above  the  dash  pot.  In  the  upper  part  of  the  case  are  the 
two  relays  and  the  snap  switches.  Good  results  have  been 
obtained  from  the  special  track  relays  employed,  which  are 
made  with  carbon  points  on  the  springs  bearing  on  German 
silver  pedestals.  The  quick-break  solenoid  relays,  controlling 
600  volts,  have  also  proved  satisfactory.  Pittsburgh  insulated 
joints  of  the  latest  pattern  are  used  in  the  track  and  are 
said  to  be  standing  up  well  under  the  heavy  traffic  which 
passes  over  them.  The  signals  and  relays  were  made  by  the 
Union  Switch  &  Signal  Co. 


SYKES   ELECTRIC   TUNNEL   SIGNAL. 

Fig.  713  illustrates  a  simple  form  of  signal  electrically 
operated  and  electrically  lighted  as  used  in  a  Sykes  installa- 
tion on  a  double-track  tunnel  line  on  the  Waterloo  &  City 
Electrical  Railway.  In  the  figures,  A  A  are  two  coils  of  an 


Fig.  712.     Circuit  Diagram  for  Solenoid.     Interborougk 
Rapid   Transit   Company,    Elevated   Lines. 


from  the  third  rail  (at  600  volts  potential)  then  flows  through 
the  solenoid  relay  armature  and  the  circuit  breaker  which  is 
closed.  This  gives  a  powerful  circuit  in  the  signal  solenoid 
to  move  the  signal  down,  but  as  soon  as  the  arm  reaches  the 
proceed  position  the  circuit  breaker  opens,  cutting  in  the  high 


electro-magnet  with  a  Z-shaped  rotating  armature,  to  which  is 
attached  a  frame  extending  around  and  in  front  of  two  white 
electric  lights  and  supporting  a  red  and  a  green  glass  be- 
tween the  lights  and  the  signal  lens ;  the  red  being  above  the 
green.  When  the  magnets  are  de-energized  by  a  train  In  the 


Names  of  Parts  of  Sykes  Tunnel 
Signal;   Fig.   713. 

A  Operating  Magnet 

B  Electric  Light 

C  Electric  Light 

D  Upper  Stop  for  Frame 

E  Lower  Stop  for  Frame 

F  Fuse 

G  Fuse 

G1  Green   Glass 

H  Armature 

J  Screw 

K  Countenveight 

L  Contact  Arm 

M  Opening  for  Indicator 

N  Indicator  Disk 

O  Binding  Post 

P  Binding  Post 

Q  Wire  Conduit 

R  Red   Glass 


Fig.    713.      Sykes   Electric   Tunnel    Signal.      Waterloo    &  City  Electric  Railway,  London,  England. 


resistance   and   allowing   only   a    small   current,   enough   to    hold 
the  signal  in  the  clear  position,  to  flow  through  the  solenoid. 

Fig.  711  shows  the  signal  mechanism  enclosed  in  the  iron 
case  at  the  foot  of  the  post.  The  solenoid  plunger  is  connected 
to  a  pivoted  lever  to  which  the  dash  pot  is  fastened  at  its 
outer  end.  The  up-and_-down  rod  is  fastened  about  midway 
between  the  solenoid  plunger  and  the  dash  pot.  Resistance 
tubes  are  mounted  on  one  side  of  the  case  and  the  circuit 
breaker  attached  to  the  up-and-down  rod  can  be  seen  Just 


block  ahead  or  for  any  other  reason,  the  frame  carrying  the 
glasses  drops  by  gravity,  bringing  the  red  glass  In  front 
of  the  lights  and  displaying  a  stop  indication.  When  the  track 
circuit  is  unoccupied  and  the  track  relay  picked  up,  the  mag- 
nets A  A  are  energized  and  the  armature  rotates,  raising 
the  frame  so  as  to  bring  the  green  glass  in  front  of  the  lamps 
and  display  a  clear  signal.  K  is  a  counterweight  carrying  an 
indicator  repeating  the  position  of  the  signal  at  the  side  of 
the  case. 


126 


BLOCK   SIGNALS. 


Figs.  7H-7I5 


SELECTIVE  SIGNALING  FOR  STEAM  AND  ELECTRIC  ROADS 


DISPATCHER    CONTROLLED    SELECTIVE    TRAIN    ORDER    SYSTEM. 

The  United  States  Electric  Co.'s  selective  train-order  system 
is  primarily  intended  for  single-track  lines.  It  is  a  combina- 
tion of  two  pieces  of  apparatus,  the  electric  slot  semaphore 
and  the  electric  selector  and  answer-back.  The  signal  blade  is 
held  in  the  safety  or  clear  position  by  a  magnet  in  the  electric 
slot,  which  is  normally  energized  by  the  local  battery.  When 
the  dispatcher  desires  to  throw  any  particular  signal  to  the 
danger  or  stop  position  he  turns  the  automatic  calling  key 
which  corresponds  to  that  signal  station,  the  same  as  In  train- 
dispatching  calling.  When  the  contact  of  the  selector  P  (Fig. 
714)  closes,  it  completes  the  circuit  of  the  semaphore  re- 
lay G.  which  then  operates  the  slot,  thus  causing  the  sema- 
phore blade  to  go  to  the  stop  position.  In  the  cc/nclusion  of 
this  movement,  a  bracket  carried  by  a  sleeve  on  the  descending 
rod  (Fig.  715)  depresses  a  plunger  and  allows  the  answer-back 
mechanism,  shown  in  the  lower  right  corner,  to  operate.  This 
mechanism  is  driven  by  a  coiled  spring  and  repeats  to  the 
dispatcher,  by  induction  over  the  telephone  wire,  the  com- 
bination number  of  the  signal  moved,  thus  assuring  him  that  it 
Is  set  at  danger.  As  soon  as  the  blade  has  finished  its  move- 
ment and  assumed  the  danger  position,  it  is  mechanically  locked. 
This  lock  holds  the  signal  against  manual  resetting  by  pulling 
down  the  blade.  After  orders  have  been  given  by  telephone 
to  the  train  crew  and  properly  verified,  the  dispatcher  gives 
permission  for  the  restoring  of  the  signal  by  reversing  the 
calling  battery  by  means  of  switch  A  (Fig.  714),  and  send- 


signal  will  set  the  signal  at  the  stop  position.  A  6'cell  10-volt 
local  battery  of  the  closed-circuit  type  is  required  at  each 
signal.  The  signal  may  be  arranged  with  double  lenses  to 
show  the  light  in  both  directions,  or  separate  signals  for 
movements  in  opposite  directions  may  be  mounted  on  a  single 
mast.  The  selective  signaling  apparatus,  when  connected  direct 
to  the  ordinary  train  dispatcher's  telephone  or  telegraph  line, 
does  not  interfere  with  the  service  at  other  stations  where 
semaphore  signals  are  not  installed. 


UNITED   STATES   ELECTRIC   SELECTIVE   SIGNALING   SYSTEM. 

The  Gill  selector  consists  essentially  of  a  ratchet  or  combina- 
tion wheel,  an  electro-magnet,  the  armature  of  which  is  ar- 
ranged to  step  the  wheel  forward,  a  retaining  pawl  to  retain 
the  teeth  stepped  and  a  mechanical  time  element,  the  function 
of  which  is  to  permit  the  retaining  pawl  to  assume  either  one 
of  two  positions,  according  to  the  length  of  the  current  impulse. 
The  time  element  consists  of  a  metal  wheel  carried  on  a 
shaft  of  small  diameter,  so  arranged  that  it  can  roll  on  its 
axis  or  shaft,  down  an  inclined  rod.  When  the  stepping  arm 
is  in  its  upper  position  the  wheel  is  prevented  from  descending, 
but  when  the  arm  moves  to  its  lower  position,  due  to  the  cur- 
rent, the  wheel  rolls  and  will  reach  its  lower  limiting  posi- 
tion provided  the  current  impulse  is  of  long  enough  duration. 
If,  however,  the  impulse  is  short,  the  stepping  arm  will  return 
to  its  upper  position  due  to  the  armature  action  and  prevent 
the  wheel  from  descending  the  full  distance.  The  time  wheel, 


D       C        B 


Semaphore  at  Clear  Posi-      Semaphore  at   Stop   Posi-       Semaphore  at   Stop   Posi- 
tion, Latched.  tion,  Locked.  tion,  Unlocked. 

Fig.  714.     Diagram  of  United  States  Electric    Company's  Selective  Train  Order  Signal  Circuit. 


Figs.   715.     United  States   Electric  Company's  Train   Order  Semaphore    Box. 


ing  again  the  station  call  by  his  individual  key.  This  again 
closes  the  selector  contact  F  and  closes  that  of  semaphore 
relay  G,  permitting  the  signal  to  be  restored  to  the  clear 
position.  Other  reference  letters  in  Fig.  714  are:  B,  C,  and 
D  calling  keys ;  E,  dispatcher's  telephone  receiver ;  H,  local  bat- 
tery ;  I,  induction  coil ;  J,  buzzer ;  K,  wires  to  semaphore 
magnet ;  L.  M.  N.  wires  to  answer-back.  In  the  operation  of 
restoring  the  signal,  the  mechanical  locking-lever  is  unlocked 
by  a  stud  carried  by  the  descending  slot  latch,  allowing  the 
signal  rod  to  be  moved  to  reset  the  blade. 

The   system    is   operated    on    a   closed   circuit   and    is   so   ar- 
ranged that  any  failure  of  the  current  supply   controlling  the 


through  a  system  of  levers,  is  so  arranged  that  it  permits  the 
retaining  pawl  to  fall  in  the  teeth  of  the  combination  wheel 
to  one-half  their  depth  if  it  is  in  the  upper  position  and  to 
the  full  depth  if  it  is  in  the  lower  position.  Some  of  these 
teeth  have  a  diagonal  slot  sawed  through  their  lower  half, 
while  others  have  the  top  of  the  tooth  diagonally  cut  away.  The 
retaining  pawl  has  a  horizontal  movement  as  well  as  a  vertical 
one.  Fastened  to  the  pawl  is  a  knife-edge  piece  which  falls 
behind  the  teeth  and  holds  the  wheel  from  returning  to  normal 
when  the  stepping  pawl  is  in  its  upper  position,  preparatory 
to  making  another  step.  If,  however,  that  part  of  the  tooth 
against  which  the  knife-edge  rests  is  diagonally  cut  away,  the 


Figs.  716-719 


BLOCK  SIGNALS. 


127 


pawl  will  be  pushed  to  one  side  and  the  wheel  will  return  to 
its  normal  position.  In  order  for  the  retaining  pawl  to  hold 
each  tooth  stepped  of  a  given  selector,  its  position  with  rela- 
tion to  the  teeth  must  be  such  that  at  no  time  does  the  knife- 
edge  rest  against  a  part  of  a  tooth  face  which  has  been 
diagonally  cut  away.  This  condition  is  brought  about  only  in 
the  case  of  a  selector  which  is  being  operated  by  the  proper 
combination  of  impulses,  and  this  selector  is  the  only  one  in 
the  circuit  which  will  close  its  contact  and  signal  the  station. 
All  other  selectors  in  the  circuit  fail  to  reach  the  contact  posi- 
tion, because  at  some  point  or  points  the  pawl  has  slipped 
out,  allowing  the  combination  wheel  to  return  to  its  initia/ 
position. 

The  Gill  selector  for  telephone  service  is  wound  to  a  resist- 
ance of  4,500  ohms  so  that  it  can  be  bridged  directly  across 
the  telephone  circuit  and  operated  without  the  use  of  relays 


on  from   eight  to   25    milli-amperes   without   change  in   adjust- 
ment. 

The  sending  of  the  proper  combination  of  current  impulses 
is  accomplished  by  automatic  calling  keys  at  the  dispatcher's 
office.  A  key  consists  of  a  spring-driven  train  of  gears  oper- 
ating a  circuit  breaker,  the  specially  cut  code  wheel  sending 
out  over  the  line  a  certain  combination  of  impulses  which  brings 
to  the  contact  position  only  that  selector  at  the  station  de- 
sired to  be  called  and  which  alone  responds  to  the  combination 
just  made.  No  adjustment  of  keys  is  necessary.  All  the  keys 
for  a  circuit  are  assembled  on  the  dispatcher's  desk  in  a  con- 
venient cabinet,  as  shown  in  Fig.  717.  The  dispatcher  is 
assured  of  the  call  being  received  at  the  station,  as  he  re- 
ceives an  answer  back  signal  from  the  station  bell  itself.  The 
Gill  bridged  telephone  selector  may  be  used  with  a  bell  rung 
by  a  local  battery  or  by  the  main  line  battery,  this  latter  being 


Fig.   716.     Dispatcher's   Desk   Cabinet. 


Fig.  718.     Local  Battery  Bell   Box  Outfit — Uncovered. 


Fig.   717.      Main    Line  Bell   Outfit — Uncovered.  Fig.  719.    Gill  Selector.    United  States  EJectric  Company. 

Figs.  716-719.     Gill  Selector  Train  Dispatching  Apparatus.     United  States  Electric  Company. 


or  local  batteries  at  the  stations,  and  without  causing  a  loss 
in  telephone  transmission.  It  is  operated  by  direct  current 
from  dry  cells,  storage  cells,  telegraph  dynamos  or  direct 
lighting  current.  The  Gill  telephone  selector  will  operate  on 
from  eight  to  25  milli-amperes  of  current,  giving  ample  margin 
of  operation  to  take  care  of  variations  in  battery  and  line. 
The  Gill  telegraph  selector  is  arranged  to  operate  directly  in 
series  with  the  line  or  from  a  sounder  battery.  It  will  operate 
on  from  200  to  600  milll-ampores  without  change  in  its  adjust- 
ment. It  is  also  wound  to  4,500  ohms  for  operation  on  a  40 
or  110  volt  local  circuit.  The  4,500-ohm  type  will  operate 


the  same  battery  as  that  sending  the  calling  impulses.  If  the 
local  battery  is  used,  two  dry  cells  are  provided  at  each  outfit 
and  the  main  signaling  battery  is  not  on  the  line  during  the 
ringing  period.  The  circuit  of  the  local  battery  bell  bridged 
telephone  is  shown  in  Fig.  720.  All  the  apparatus  shown  at 
the  way  station  is  assembled  in  a  box.  When  both  the  selector 
and  bell  are  supplied  with  current  from  the  main  signaling 
battery,  the  station  apparatus  is  reduced  to  a  minimum. 
Although  calling  by  the  main  line  bell  battery  causes  a  slightly 
larger  current  flow  from  the  main  signaling  battery  every  time 
a  station  is  called,  the  increased  current  is  not  very  great, 


128 


BLOCK   SIGNALS. 


Figs.  720-725 


as  high,  resistance  bells  of  1,800  ohms  are  used,  requiring  eight 
to  12  mils  to  operate  satisfactorily,  and  but  one  bell  is  in 
circuit  when  a  station  is  called. 


DISPATCHER'S  STATION 


TJ^T 

-m""         I  I       ftftm 


fp       IP 

CONDENSERS 


WAY  STATION 


Fig.    720.     Local    Bell    Circuit,    Bridged    Telephone 
Selector. 

There  is  no  tendency  for  the  bells  to  tap  in  other  stations 
than  that  called,  as  there  is  no  passing  contact  and  no  bell 
circuit  except  that  selected  is  closed  even  momentarily. 


G.     R.     S.     SELECTIVE     SIGNALING     SYSTEM. 

The  General  Railway  Signal  Co.'s  system  of  selective  signal- 
Ing  provides  means  whereby  a  dispatcher  may  call  to  the  tele- 
phone, station  operators  or  train  crews  for  the  purpose  of  giv- 
ing them  orders.  When  a  station  operator  is  to  be  called,  it  is 
only  necessary  to  ring  a  bell  letting  the  operator  know  that  he 
Is  wanted  on  the  telephone.  When  a  train  crew  is  to  be  called, 
It  is  further  necessary  to  give  a  visual  signal.  If  required  an 
"answer  back,"  visual  or  audible,  can  be  provided  as  an  indi- 
cation that  the  system  has  operated  properly. 

The  system  embodies  new  principles  with  desirable  features, 
viz. :  The  method  of  supplying  operating  current  which  results 
in  great  economy  of  operation ;  the  high-speed  positive-acting 
selector,  which  has  a  range  of  324  different  calls  and  which 
can  close  any  one  of  six  different  circuits  at  a  given  station  : 
the  calling  bells,  either  a.  c.  or  d.  c.,  of  a  design  similar  to  the 
selector ;  the  simple  automatic  calling  key  of  the  messenger  call 
box  type,  and  the  system's  adaptation  to  use  with  any  standard 
telephone  equipment. 

Stations  can  be  added  if  so  wished  without  interfering  with 
the  operation  of  existing  stations.  Each  station  can  be  arranged 
to  call  any  other  station. 

The  selector  (Fig.  725)  operates  on  seven  milli-amperes,  using 
a  new  design  of  pawl  and  ratchet  movement,  in  which  the  pawl 
is  forced  into  position  upon  the  completion  of  each  step  and  is 
not  dependent  upon  spring  action  or  gravity  for  its  proper 


Energy  for  the  operation  of  the  system  is  provided  by  a  small 
motor  generator  set  mounted  below  the  switchboard.  The  motor 
operates  from  a  12-volt  battery.  The  generator  is  compound 
wound  and  supplies  current  for  both  bell  and  selector  operation 
at  constant  voltage;  no  local  batteries  are  therefore  required  at 
local  stations.  The  motor  generator  set  normally  is  not  run- 
ning, but  is  started  and  stopped  automatically  with  the  begin- 


Fig.    721.     24-Station    Calling    Key    Cabinet. 
Railway  Signal  Company. 


General 


ning  and  completion  of  eacli  call.  By  the  use  of  this  feature 
each  average  circuit  can  be  operated  at  a  cost  of  less  than 
$3  per  year. 

The  switchboard  carries  a  volt-ammeter,  necessary  switches 
for  the  control  of  the  system,  underload  circuit  breaker,  am- 
meter plugs,  etc.,  and  a  line  and  motor  control  relay  of  the 
same  general  design  as  the  selector. 


Fig.    722.     Dispatcher's    Equipment.      I.    C.    R.    R. 

Fig.  726  shows  circuits  for  operation  of  a  system  using 
d.  c.  bells.  To  simplify  the  circuits  a  single  calling  key  is 
shown  instead  of  a  number  connected  in  parallel,  and  likewise 
on  the  receiving  end  of  the  circuit  the  station  is  shown  for  the 
key  in  question  only.  Contact  disks  7-8-9  of  key  1  are  shown 


Fig.  723.     Line  Relay. 


Fig.   724.     A.   C.   Bell. 


Fig.  725.     G.  R.  S.  Selector. 


operation.  The  selector  usually  furnished  will  control  two  cir- 
cuits. This  can  be  made  to  control  up  to  six  circuits  by  the 
addition  of  contact  springs  and  a  mounting  block. 

Fig.  721  shows  a  24-station  calling-key  cabinet  with  the 
front  of  case  removed.  Each  key  may  be  individually  removed 
from  the  containing  case  without  disarranging  any  contacts. 
The  keys  are  so  mounted  that  all  electrical  connections  are 
made  to  bus  bars,  eliminating  the  use  of  wire  in  the  interior 
of  the  cabinet. 


apart,  whereas  in  reality  they  are  fastened  to  a  common  shaft. 
To  the  left  of  the  dotted  line  is  the  apparatus  located  in  the 
dispatcher's  office  and  to  the  right  a  local  station  ;  2-3-4-5  are 
spring  contacts  closed  by  rotation  of  disks  7-8-9  and  sector  6 ; 
12  is  a  12-volt  battery;  13  is  the  motor,  and  14  the  generator 
in  the  d.  c.  motor-generator  set;  15  and  16  their  fields,  respect- 
ively; 18  a  polarized  line  relay.;  19-19  its  operating  coils,  and 
26  and  27  are  the  retardation  coils  and  condenser  which  make 
the  line  available  for  telephone  use. 


Figs.  726-728 


BLOCK   SIGNALS. 


129 


Fig.  726.     Typical  Selector  Circuit  Using  D.  C.  Bell.      General  Railway  Signal  Company. 


AUTOMATIC  CALLING  KEY  1 

6 


35    = 

Fig.  727.     Typical  Selector  Circuit  Using  A.  C.  Bell.     General  Railway  Signal  Company. 


36   = 


]Fig.   728.     Selector  Used   in    Connection   with  Automatic  Block  Signals.     General  Railway  Signal   Company. 


130 


BLOCK  SIGNALS. 


Fig. 


To  the  right  of  the  dotted  line  is  a  way  station  with  a  se- 
lector 28  bridged  across  the  line  46-47;  29-29  are  its  operating 
coils;  30  is  a  variable  resistance  inserted  to  balance  the  line 
drop;  31  a  contact  closed  by  operation  of  the  selector;  and  34 
is  a  d.  c.  bell. 

To  operate  the  selector,  a  small  handle  fastened  to  sector  6 
of  the  automatic  key  1  is  turned  clockwise,  through  an  arc  of 
72  deg.  against  a  spiral  spring,  thereby  making  contact  between 
sector  6  and  contact  spring  2.  This  picks  up  motor  control 
relay  10  and  starts  motor-generator  set  13-14  through  the  clos- 
ing of  contact  11.  When  the  handle  is  released  the  contact  disks 
7-8-9  geared  to  sector  6  begin  one  counter-clockwise  revolution. 
The  teeth  of  disk  7  first  make  contact  with  spring  3  and  thus 
make  and  break  a  circuit  which  actuates  polarized  relay  18 
once  for  each  tooth  on  disk  7.  This  closes  contact  points  20-21 
and  23-24  a  like  number  of  times  and  through  them  are  sent 
out  a  number  of  pulsations  on  to  line  46-47  from  ^generator  14. 
These  pulsations  cause  the  stepping  up  of  the  sector  A  of  se- 
lector 28  the  number  of  times  equal  to  the  pulsations  received. 

The  teeth  of  disk  8  in  making  contact  with  spring  4  likewise 
send  pulsations  of  current  on  to  line  46-47,  but  of  opposite 
polarity,  and  cause  the  stepping  up  of  the  sector  B. 

The  contact  arms    (not  shown)    of  the  selector  being  rigidly 


previously  described ;  37  is  a  polarized  relay  similar  to  relay 
18,  controlled  through  contacts  31-32  on  selector  28;  44  is  a 
signal  mechanism,  and  45  is  a  track  relay  controlling  same. 
Relay  37  is  shown  in  its  normal  position,  with  contact  40-41 
closed.  The  dispatcher  in  reversing  relay  37  breaks  the  signal 
circuit  by  opening  40-41,  and  rings  the  bell  34  through  the 
closing  of  contacts  39-40.  The  signal  if  clear  will  go  to  block. 

The  insertion  of  a  telephone  plug  in  the  jack  42  at  the  signal 
will  automatically  restore  the  signal  providing  there  is  no  train 
within  the  section  protected  by  the  signal,  and  cause  the  bell 
to  stop  ringing.  This  may  also  be  done  by  the  dispatcher 
through  his  restoring  relay  37  to  its  normal  position. 

The  selector  also  may  be  used  In  connection  with  a  train 
dispatcher  system  in  which  the  movement  of  trains  is  governed 
by  means  of  train  order  signals.  When  these  are  used  a  dis- 
tinctive "answer  back"  is  required,  either  when  clearing  the 
signal  or  putting  it  to  block. 


THE   BLAKE    SIGNAL. 

This  is  a  non-automatic  signal  apparatus  by  which  a  number 
of  signals  at  different  points  along  a  railroad  are  made  sub- 
ject to  the  control  of  the  dispatcher  at  a  central  point.  H* 

45Mi/es  ofWo./O/rorr  W/re     Confacf  c/osec/  by  eac/r  swrry  of 
,'/8  Ohms  per  m//e.        pencfu/urrr  when  enpapecf 


GSOhms- 


A/l  regru/afinq  Co//s  450  Ohms  each 


Deact  Res/sfance 
\Cp//s/Vo  /Line 


Ground  end  ofL/ne. 


Fig.  729.     Arrangement  of  Circuits  for  Blake  Dispatcher's  Signal. 


fastened  to  the  sectors  A  and  B  will  now  be  in  such  a  relative 
position  that  the  next  impulse,  caused  by  the  contact  of  9  to  5, 
will  actuate  the  selector  so  as  to  close  contact  31,  thereby 
ringing  bell  34. 

The  contact  between  disk  9  and  spring  5  is  maintained 
through  70  deg.  of  its  rotation  and  through  this  length  of  time 
bell  34  will  continue  to  ring.  Circuits  formed  between  6  and  2, 
and  9  and  5,  are  broken  simultaneously  when  all  parts  return 
to  normal  position. 

Fig.  727  shows  circuits  where  a.  c.  bell  is  used  ;  17  Is  a  tap 
from  armature  winding  of  generator,  carried  through  armature 
shaft  and  insulated  therefrom,  to  ground  35.  Alternating  cur- 
rent potential  will  exist  between  ground  35  and  line  wires 
46-47,  and  when  contact  31  is  closed  a.  c.  current  will  flow  from 
both  wires  46-47  through  bell  34  and  condenser  33  to  ground  36, 
causing  bell  to  ring. 

The  use  of  the  selector  in  conjunction  with  automatic  signals 
is  illustrated  by  Fig.  728.  The  local  station  with  signal  is 
shown,  but  not  the  dispatcher's  office.  Selector  28  is  same  as 


is   able   to   set   in   the   stop   position   a   semaphore   of   standard*'' 
size,    and    by    a   selective    apparatus    he    controls    a    number    of' 
signals   by    means    of   a   single   wire.      The   system    is    used   on  i 
electric   railroads   where   cars   are   required   to   stop   at   signals, 
the    conductor    then    inquiring    by    telephone    for    orders.      The" 
selection  is  obtained  accurately  by  means  of  the  principle  that 
the   time   of   vibration   of  a   pendulum    varies   with    its   length. 
A  No.  10  bare  iron  wire  is -used  on  a  line  controlling  a  series' 
of   15    signals. 

When  the  dispatcher  wishes,  for  example,  to  set  signal  No.  9- 
he  inserts  a   plug  in   hole   No.   9   on   his   desk  and   thereby   re- 
leases    pendulum  No.   9  in  the  desk  and  also  connects  the  line1 
with    the    source    of    the    electric    current.      As    the    pendulum 
in  the  dispatcher's  desk  swings  It  open  and  closes  the  circuit, 
sending    impulses    over    the    line    synchronous    with    its    vibra- 
tion.    At   the  end  of  ten  seconds  the  pendulum   at   signal    No.-. 
9  swings  through  an  arc  wide  enough  to  trip  a  lock  and  drop1.' 
the  semaphore  arm  to  the  stop  position.      (It  is  turned  upward' 
to    indicate    proceed.)      As    soon    as    the    semaphore    arm    has< 


Figs.  730-733 


BLOCK   SIGNALS. 


reached  the  horizontal  position  it  throws  an  interrupted  ground 
on  the  line  at  that  point,  which,  causes  an  additional  amount 
of  current  to  flow  through  the  relay  on  the  dispatcher's  desk, 
causing  it  to  attract  its  armature  in  unison  with  the  swing 
of  the  pendulum  ;  thus  the  dispatcher  receives  a  positive  indi- 
cation of  the  semaphore  arm  being  set  at  "stop." 


Dispatcher's    Desk;    Blake    Dispatcher's 
Signal. 

When  the  car  or  train  has  arrived  at  this  point  and  com- 
municated, with  the  dispatcher  by  telephone,  the  dispatcher 
withdraws  his  plug  and  the  conductor  clears  the  signal. 


WESTERN    ELECTRIC    SELECTIVE     SIGNAL. 

The  selector  shown  in  Fig.  731,  which  was  developed  by  the 
Western  Electric  Co.  for  selective  telephone  calling,  has  been 
combined  with  apparatus  made  by  the  Union  Switch  &  Signal 
Co.  to  form  a  selective  signal  system  by  which  the  dispatcher 
can  set  any  signal  at  will,  the  control  being  carried  out  to  the 
signals  by  a  single  pair  of  wires.  Fig.  732  shows  the  box 
mounted  on  the  signal  pole  which  contains  the  telephone  set  and 
local  station  apparatus  and  Fig.  733  is  a  view  of  the  box  open 
showing  the  selector  and  the  signal  operating  mechanism.  The 
signal  is  of  standard  construction  and  can  be  arranged  to  pro- 
vide either  upper  or  lower  quadrant  indications.  It  is  electrically 


Fig.  731.     No.  5oA  Selector. 


operated  and  manually  restored,  ten  dry  cells  being  required. 
An  important  feature  of  the  operation  of  the  system  is  the 
distinct  "answer  back"  which  the  dispatcher  receives  when  the 
signal  movement  has  been  completed. 


STROMBERG-CARLSON    DISPATCHER'S     SIGNAL. 

The  Stromberg-Carlson  telephone  train  dispatching  apparatus 
consists  essentially  of  cl.ock  work  mechanisms  for  selecting  local 
stations  from  a  master  station,  an  electrical  trip  at  each  local 
station  for  setting  the  semaphore  signal,  a  clock  work  mechan- 
ism for  answering  back  at  the  completion  of  the  stroke  of  the 


signal  trip,  and  a  tape-recording  device  at  the  master  station, 
upon  which  the  answer-back  records  the  fact  that  the  signal 
is  gone  to  danger.  The  standard  clock  work  selector  is  driven 
by  a  weight  which  is  controlled  by  a  pendulum,  so  that  all 


Fig.  732.     Pole  Casting. 

clocks  in  the  system  run  at  the  same  rate.  The  operation  of 
the  clock  rotates  a  disc  carrying  a  contact  finger  which  moves 
over  a  set  of  contacts,  as  shown  in  Figs.  734  and  735.  Fig.  734 
is  the  clock  mechanism  at  the  master  station  and  Fig.  735  the 
standard  mechanism  for  the  local  station.  To  illustrate  the 


Fig-  733-     Apparatus  Casting  Showing  Parts. 

procedure  in  selecting  any  desired  local  station,  assume  that 
the  master  clock  is  regulated  so  that'  the  contact  finger  requires 
three  seconds  to  move  from  the  position  shown  to  the  contact 
marked  2.  If  the  local  station  mechanism  is  adjusted  so  that 
its  contact  finger  also  reaches  the  second  contact  in  three 
seconds,  it  is  evident  that  if  a  current  of  electricity  is  sent  over 
the  wire  at  the  end  of  three  seconds  from  the  time  the  clocks 
are  simultaneously  started  the  circuit  will  be  closed  through 
the  apparatus  at  the  local  station  and  any  operating  mechanism 
in  that  circuit  will  receive  current.  If  it  requires  three  seconds 
additional  for  the  contact  finger  of  the  master  selector  to  move 


132 


BLOCK   SIGNALS. 


Figs.  734-739 


from  contact  2  to  3,  and  a  second  local  selector  is  adjusted  to 
close  its  contact  in  six  seconds,  that  station  will  be  selected  if 
a  current  is  sent  over  the  wire  at  the  end  of  six  seconds. 

The  contact  finger  on  the  master  station  selector  is  arrested 
by  a  pin  inserted  in  a  hole  corresponding  with  the  station  which 
it  is  desired  to  call.  An  electro-magnet  operating  a  friction 
clutch  retains  the  disc  and  contact  finger  in  the  position  at 
which  it  is  stopped  by  this  pin  until  a  current  is  sent  through 
the  electro-magnet  to  release  the  clutch  upon  which  the  disc 
and  finger  are  returned  to  the  zero  or  starting  position  by  the 
small  weight  2.  The  local  station  selector  makes  contact 
through  a  contact  segment  (1)  through  the  brushes  (2).  This 
disc  can  be  set  at  any  desired  angle  from  the  brush  and  this 
angle  governs  the  period  through  which  the  selectors  move 


Fig.    734.      Master 
tion  Selector. 


Sta-         Fig.    735.      Local 
tion  Selector. 


Sta- 


before  that  station  is  selected.  An  adjusting  screw  (3)  is  pro- 
vided for  adjusting  this  position  of  the  segment  accurately. 
A  stop  pin  (4)  arrests  the  movement  of  the  clock  when  it  has 
carried  the  segment  in  the  disc  past  the  brush,  since  any  fur- 
ther movement  is  unnecessary  and  results  in  useless  wear.  This 
also  materially  reduces  the  amount  of  winding  necessary  to 
keep  the  clock  in  continuous  operation.  Under  ordinary  condi- 
tions it  is  only  necessary  to  wind  the  local  station  clock  once 
in  two  months,  and  the  circuit  is  so  arranged  that  if  the  clock 
is  not  wound  the  current  is  thrown  directly  through  the  trip 
mechanism  at  each  impulse  of  current  from  the  master  station, 
resulting  in  a  stop  signal  which  cannot  be  cleared  until  the 
train  men  wind  the  clock. 

The  trip  and  repeat-back  mechanism  shown  in  Fig.  739 
consists  of  a  vertical  rod  mounted  in  guides  on  a  slate  base, 
which  is  held  locked  in  its  lowest  position  by  the  lever  2,  which, 
in  turn,  is  held  by  a  catch  3  on  the  armature  of  an  electro- 
magnet. The  down  position  of  this  rod  corresponds  to  the  clear 
position  of  the  semaphore  blade,  and  when  the  electro-magnet 
is  energized,  tripping  the  lever  and  allowing  the  rod  to  rise, 
the  signal  assumes  the  danger  position  by  gravity.  The  re- 
peat-back, which  is  mounted  on  the  same  base,  is  a  clock  move- 
ment wound  each  time  the  vertical  rod  is  returned  to  its 
locked  position.  The  vertical  rod  near  the  end  of  its  upstroke 
lifts  the  release  lever  4  of  the  repeat-back  and  allows  the  clock 
movement  to  rotate  the  disc  5.  This  disc  causes  breaks  in  the 
main  line  corresponding  to  the  number  assigned  to  the  local 
station  at  which  it  is  installed.  The  vertical  rod  of  the  trip 
cannot  be  returned  to  its  locked  position  until  the  repeat-back 
disc  lias  completed  its  full  revolution  ;md  finished  registering 
its  number  on  the  recording  tape  at  the  master  station.  The 
repeat-back  mechanism  is  restored  to  its  normal  position  by  the 
same  operation  which  returns  the  signal  to  the  clear  position. 
The  tape-recording  device  consists  of  a  clock  movement  which 
carries  a  paper  tape  under  a  perforating  pin  or  point  which 
is  attached  to  the  armature  of  an  electro-magnet  controlled  by 
the  current  in  the  line.  When  this  current  is  broken  by  th<> 
repeat-back  mechanism  at  a  local  station  a  series  of  holes  is 
punched  in  the  tape  corresponding  to  the  number  of  interrup- 
tions made  by  the  local  station  apparatus.  A  single  pole, 
double-throw,  hand  switch  is  used  at  the  master  station  to  con- 
trol the  application  of  current  to  the  line. 

The  operation  of  the  system  is  illustrated  in  the  diagrammatic 
drawing  shown  in  Fig.  736.  All  selectors  in  the  diagram  an 


shown  in  the  resting  position,  that  is,  after  the  movement  of 
the  clock  has  been  checked  by  the  pin  stops.  Under  these  con- 
ditions the  first  operation  is  to  close  the  battery  switch  in  the 
upward  position,  allowing  current  to  flow  through  the  electro- 
magnets of  each  selector,  releasing  the  friction  clutch  and  al- 
lowing the  discs  carrying  the  controller  fingers  to  return  to  the 
zero  position.  This  also  releases  the  clock  movement  and  the 
pendulums  in  all  clocks  begin  to  beat,  allowing  them  to  run  at 
their  normal  speed.  The  operator  at  the  master  station  then 
selects  the  desired  local  station  by  inserting  the  pin  in  the  hole 
in  the  master  selector  corresponding  to  this  station,  after  which 
he  throws  the  battery  switch  in  the  downward  position.  This 
removes  battery  from  the  line,  allowing  the  electro-magnets  to 
operate  the  friction  clutches  which  immediately  pick  up  their  re- 


Semaphore-  S/ofion  Sfmqahoro  Jibfton 

Figs.  736-738.     Diagram  Showing  Operation  of  System. 


00000 


Fig.    739-     Trip    and    Repeat    Back    Mechanism. 

spective  discs  and  the  contact  fingers  are  all  moved  forward 
simultaneously.  The  downward  movement  of  the  switch  also 
transfers  the  battery  through  the  tape  recorder  to  the  arm  of 
the  selector  so  that  when  this  arm  comes  into  contact  with  the 
inserted  pin,  battery  is  again  placed  on  the  line.  At  the  instant 
that  this  contact  is  closed  the  contact  segment  of  the  station 
to  be  selected  comes  under  the  brushes  and  the  circuit  of  com- 
paratively low  resistance  is  closed  through  the  release  magnets 
of  this  station's  trip  and  repeat-back  mechanism.  This  release 
magr>''  operates  and  cuts  itself  from  the  line,  allowing  the  cur- 
rent to  flow  through  the  normal  line  which  restores  all  clocks 
to  the  zero  position  again.  The  trip  release  magnet  allows  the 
lever  and  vertical  rod  to  move  under  the  pull  of  the  semaphore 
which  moves  to  the  danger  position.  The  vertical  rod  as  it 
moves  up  operates  the  repeat-back,  which  in  turn  records  on  the 
tape  at  the  master  station,  giving  evidence  that  the  signal  at 
that  station  has  gone  to  danger. 


INTERLOCKING.  133 


INTERLOCKING 
Pages  134-296  Figures  740-2088 

Pages  Figures 

MECHANICAL .  134-209  740-1761 

PRINCIPLES  OF   INTERLOCKING 134-143  740-789 

MACHINES 143-156  790-1006 

MECHANICAL  INTERLOCKING 
PARTS  AND  DETAILS  OF 

CONSTRUCTION       % 156-209  1007-1761 

POWER 210-279  1762-2054 

ELECTRIC 210-254  1762-1954 

ELECTRO-PNEUMATIC        .'...' 254-271  1955-2028 

LOW  PRESSURE  PNEUMATIC      272-275  2029-2040 

ELECTRO-MECHANICAL 276-277  2041-2044 

POWER  OPERATED  SIGNALS  AT 

MECHANICAL    PLANTS 277-279  2045-2054 

ELECTRIC  LOCKING  280-296  2055-2088 


134 


INTERLOCKING. 


Figs.  740-743 


MECHANICAL 


PRINCIPLES  OF  INTERLOCKING 


The  concentration  of  a  considerable  number  of  switch  or 
signal  levers  in  the  hands  of  one  man  would  naturally  re- 
sult in  the  operator  at  some  time  mistaking  the  lever  which 
he  was  to  throw.  Through  such  an  error  a  train  might  be 
derailed  or  diverted  from  its  proper  course,  or  a  signal  per- 
mitting a  certain  movement  might  be  displayed  at  the  same 
time  another  signal  permitting  a  conflicting  movement  was 
given.  To  prevent  occurrences  of  this  kind  the  various  levers 
operating  a  number  of  switches  and  signals  placed  together 
in  one  bank  'or  stand  are  so  interconnected  that  only  proper 
and  non-conflicting  movements  can  be  made.  This  intercon- 
necting of  devices  used  to  operate  switches  or  sigpals  so  that 
their  movements  can  only  occur  in  predetermined  sequence 
la  called  "interlocking,"  and  the  assemblage  of  stands,  levers 
and  connections  is  called  an  "interlocking  machine." 

The  manner  in  which  the  interlocking  of  the  levers  is 
accomplished  may  be  understood  by  reference  to  Figs.  740-743  ; 
which  show  a  track  layout  and  the  locking  sheet  and  dog  charts. 
The  dog  chart  is  the  working  drawing  by  which  the  locking 
is  laid  out  and  is  a  miniature  diagram  of  the  locking  as  it 
appears  in  the  machine. 

The  interlocking  plan  illustrated  in  Figs.  740-743  shows  a 
single-track  layout,  with  one  siding.  A  derail  is  placed  at 
the  fouling  point  on  the  siding  to  prevent  a  car  or  train  on 
the  siding  from  coming  out  where  it  would  collide  with  a 
train  on  the  main  line.  The  derail  .  and  the  switch  are  oper- 


running  from  left  to  right  as  the  towerman  faces  the  machine. 
In  Fig.  742  is  shown  a  locking  sheet  for  the  interlocking 
plant  illustrated  in  Fig.  740.  Before  proceeding  to  make  this 
locking  sheet,  the  routing  of  the  various  signals  should  be 
determined.  When  an  engineman  passes  a  clear  distant  signal, 
it  indicates  a  clear  route  through  the  interlocking.  There- 
fore, the  reversal  of  lever  1,  controlling  the  distant  signal, 
should  lock  home  signal  lever  2  reversed  and  2  reversed  should 
lock  switch  and  derail  lever  5  normal,  so  that  switch  5 
and  home  signal  2  will  be  in  their  correct  positions  for  a 
through  movement  from  distant  signal  1.  Home  signal  lever 
2  reversed  should  also  lock  home  signal  lever  7  normal  to 
prevent  the  clearing  of  the  two  con-flicting  home  signals,  " 
and  7,  at  the  s<^me  time.  Dwarf  signal  lever  3  reversed  should 
lock  switch  and  derail  lever  5  reversed,  as  the  derail  should 
be  closed  and  the  switch  reversed  before  a  train  is  allowed 
to  proceed  over  them.  Dwarf  signal  3  reversed  should  also 
lock  home  signal  lever  6  normal  to  prevent  dwarf  signal  3 
and  home  signal  6  from  being  both  in  the  clear  position  at 
the  same  time.  Home  signal  lever  6  reversed  should  lock  5 
reversed  so  that  switch  and  derail  controlled  by  lever  5  will 
be  in  the  correct  position  for  a  movement  from  the  main  line 
to  the  siding.  Home  signal  lever  7  reversed  should  lock  switch 
and  derail  lever  5  normal,  so  that  the  derail  will  be  open 
and  the  switch  in  the  correct  position  for  a  movement  on 
the  main  line.  Lever  8  reversed  should  lock  lever  7  reversed, 


Plan. 


MACHINE: 

6  LEVERS  FOR  6  SIGNALS 

_l_  LEVER  FOR  I  SWITCH  AND  I  DERAIL^ 

7  WORKING  LEVERS 
J_  SPARE  SPACE  :  4 

8  LEVER  FRAME 


Locking  Sheet. 


"Standard"    Dog    Chart. 


"Saxby  &  Farmer"  Dog  Chart. 


Figs.  740-743.     Interlocking  Plan,  Locking  Sheet  and  Dog  Charts;  Single  Track  and  Turnout. 


ated  by  one  lever,  No.  5.  A  dwarf  signal  is  located  approxim- 
ately 55  ft.  back  of  the  derail  to  control  movements  from 
the  siding.  Home  signal  2,  which  is  located  at  the  fouling 
point  of  the  two  tracks,  protects  movements  over  switch  5.  It 
is  placed  so  as  to  permit  a  movement  to  or  from  the  siding 
while  a  train  is  standing  at  (in  the  rear  of)  it.  No.  1  is  a 
distant  signal  for  home  signal  2  and  is  located  a  sufficient 
distance  in  the  rear  of  2  to  enable  an  engineman  to  get  his 
train  under  control  before  he  reaches  the  home  signal,  if  the 
distant  signal  should  indicate  "caution"  when  he  passed  it. 
Levers  6  and  7  control  a  two-arm  home  signal  placed  about 
55  ft.  back  of  the  switch  point.  Lever  7  operates  the  top 
arm  which  governs  movements  on  the  main  line,  and  lever 
6  the  lower  arm  for  movement  from  the  main  track  to  the 
siding.  No.  8  is  the  distant  signal  for  home  signal  7. 

The  different  functions  are  so  connected  that  when  the 
signalman  is  operating  levers  at  one  end  of  the  machine,  the 
signals,  etc.,  operated  will  be  located  at  the  corresponding 
end  of  the  interlocking  plant.  The  heavy  black  line  in  the 
tower  designates  the  position  of  the  machine  and  the  dot 
represents  the  signalman.  These  positions  should  be  deter- 
mined before  proceeding  to  allot  numbers  to  the  levers  con- 
trolling the  various  functions.  When  numbering  a  signaled 
layout,  .such  as  shown  in  Fig.  740,  it  is  the  practice  first  to 
number  the  high  signals,  then  the  dwarf  signals,  for  move- 
ments in  one  direction ;  then  part  of  the  spare  spaces  or  levers, 
If  any;  then  the  switches,  derails  and  facing  point  locks; 
then  the  remaining  spare  spaces  or  levers;  and,  finally,  the 
signals  for  movements  in  the  opposite  direction,  the  numbers 


which  lever  controls  the  high  speed  arm  of  the  two-arm  home 
signal,  so  that  when  distant  signal  8  is  in  the  clear  position, 
derail  5  will  he  open,  switch  5  will  be  set  for  the  main  lino 
and  home  signal  7  will  be  in  the  clear  position,  thereby 
setting  up  a  clear  route  from  the  distant  signal  through  the 
interlocking.  With  all  signals  normal,  lever  5  may  stand 
normal  or  reversed,  the  position  of  switch  and  derail  con- 
trolled by  that  lever  being,  under  these  conditions,  immaterial. 
It  is  apparent  that  if  any  of  the  signals  are  in  the  clear 
position  it  would  be  impossible  to  reverse  lever  5,  because  it 
would  be  locked  in  one  position  or  the  other  by  the  reversal 
of  the  signal  lever.  If  a  train  is  making  a  movement  on  the 
main  line,  another  train  cannot  leave  the  siding,  as  5  would 
be  locked  normal  by  2  or  7  reversed,  it  being  impossible  for 
the  signalman  to  reverse  lever  3  unless  5  is  reversed.  Again, 
if  a  train  is  making  a  movement  to  or  from  the  siding,  it 
is  impossible  to  reverse  lever  2  and  give  a  clear  home  signal, 
as  this  lever  calls  for  5  in  the  normal  position  and  lever 
5  would  necessarily  have  to  be  reversed  for  _the  movement  to 
or  from  the  siding. 

The  locking  sheet  shows  that  2  reversed  locks  7  normal, 
which  is  the  same  as  7  reversed  locks  2  normal  (see  dog. 
chart.  Fig.  741).  This  condition  prevails  in  all  cases  where 
one  lever  reversed  locks  another  lever  normal,  the  first  lever 
that  is  reversed  locks  the  other  lever  in  the  normal  position. 

Before  proceeding  to  make  a  dog  chart  it  is  necessary  to 
ascertain  from  the  locking  sheet  whether  or  not  any  two  or 
more  levers  lock  any  other  lever  or  levers  in  certain  positions. 
Very  frequently  dogs  may  be  grouped  together  on  one  locking 


Figs.  744-749 


INTERLOCKING. 


bar,  thereby  economizing  space  and  material,  and  it  is  very 
often  possible,  by  means  of  a  butt,  to  avoid  duplication  of 
locking  bars  for  the  reason  that  if  this  were  not  done  two 
sets  of  dogs  performing  exactly  the  same  functions,  but  using 
two  separate  bars  and  occupying  two  spaces  in  the  locking 
frame,  would  be  required.  For  instance,  2  and  7  reversed 
lock  5  normal.  This  is  also  true  of  levers  3  and  6  which, 
when  reversed,  lock  5  reversed,  but  it  is  inadvisable  to  follow 
the  above  method  in  this  particular  case,  as  the  butt  would 
have  to  be  placed  between  dogs  on  either  side  of  tappet  5, 
as  shown  dotted,  in  the  fourth  space,  and  this  would  leave 
a  very  short  piece  of  bar  on  the  double  dog  to  the  right  of 
tappet  5,  which  would  be  likely  to  twist  to  one  side  and 
make  the  butt  ineffective.  Of  course,  if  cramped  for  space  in 
a  machine,  the  short  bar  referred  to  can  be  extended  to  the 
right  and  a  guide  dog  fastened  to  its  end.  This  construction 
would  make  such  an  arrangement  satisfactory. 

In    the    locking    sheet    lever   No.    5    is    shown    as    performing 


for  switch  and  lock  movements.  This  necessitates  a  slight 
variation  in  locking  because  the  facing  point  lock  levers,  when 
reversed,  lock  the  switches  either  normal  or  reversed.  It  Is 
necessary  with  this  arrangement  of  tracks  to  make  the  home 
signal  2-3  a  two-arm  signal.  The  top  arm  2  governs  move- 
ments on  the  main  line,  over  switches  8  and  10  normal,  the 
lower  arm  3,  movements  to  the  siding,  over  8  normal  and 
10  reversed. 

Notice  should  be  given  to  the  method  of  numbering  the 
facing  point  locks,  derails  and  switches.  First  is  fa'cing  point 
lock  7,  locking  derail  8 ;  then  facing  point  lock  9,  locking 
switches  8  and  10;  and,  finally,  facing  point  lock  11,  locking 
derail  10.  This  arrangement  of  levers  insures  a  good  run  of 
the  connections  operating  the  facing  point  locks,  switches 
and  derails.  It  also  brings  next  to  one  another  the  levers 
which  are  to  be  operated  consecutively ;  for  instance,  when  a 
signalman  throws  switch  8  or  10,  he  must  then  throw  facing 
point  lock  lever  9  to  lock  it.  Furthermore,  it  simplifies,  to  a 


Plan. 


"Saxby  &  Farmer"  Dog  Chart. 


MACHINE 

8   LEVERS  FOR  8  SIGNALS 
Z.       .  .2  SWITCHES  AND  2  DERAILS 

_3_       .  .    4.F.RLS. 

13    WORKING  LEVERS 
I    SPARE  SPACE  1  5 . 

_§_      .      LEVERS:  e.iz 

16    LEVER  FRAME 


Locking   Sheet. 


Details     of     Locking; 

Standard  Machine. 
Standard     Dog  Chart. 

Figs.    744-749.      Interlocking    Plan,    Locking    Sheet    and    Dog    Charts;    Single    Track.    Two    Turnouts. 


no  locking  function,  but  an  inspection  of  the  sheet  shows  that 
this  lever  occurs  in  four  combinations,  namely  2,  3,  6  and  7 
and,  if  it  were  desirable,  it  could  be  stated  in  the  sheet  that 
lever  5  reversed  locks  2  normal  and  7  normal ;  also  when  5 
Is  normal  it  locks  3  and  6  normal ;  but  this  is  not  done  as 
it  would  be  merely  a  restatement  of  what  is  already  shown. 
In  the  same  manner  it  might  be  said  in  the  locking  sheet  that 
lever  7  reversed  locks  lever  2  normal.  The  locking  sheet  Is 
made  up  as  a  guide  to  the  preparation  of  the  dog  chart,  and 
everything  that  appears  in  the  locking  sheet  should  appear 
in  the  dog  chart.  If  the  repetitions  as  above  stated  should 
appear  in  the  locking  sheet,  they  would  appear  in  the  dog 
•chart  as  unnecessary  or  overlooks.  They  are,  therefore, 
omitted. 

Interlocking  plan  shown  in  Fig.  744  differs  from  that 
Illustrated  in  Fig.  740  only  to  the  extent  of  an  additional 
siding  connecting  with  .the  main  line.  The  signaling  necessary 
to  cover  this  addition  is  worked  out  on  the  same  basis  as 
the  scheme  employed  for  the  single  turnout,  with  the  excep- 
tion of  the  facing  point  locks,  which  have  been  substituted 


certain  extent,  the  arrangement  of  the  locking  on  the  dog  chart. 
As  shown  on  the  plan,  derail  and  switch  8  are  operated  by 
one  lever,  ns  it  is  always  necessary  to  have  both  either  normal 
or  reversed  at  the  same  time.  Lever  10.  controlling  switch 
and  derail,  is  a  similar  instance.  As  it  is  always  necessary 
to  use  9  when  either  7  or  11  is  being  used,  it  is  possible  to 
operate  either  7  and  9,  or  9  and  11,  with  one  lever;  but  this 
is  not  advisable.  With  the  arrangement  as  shown  it  is  Im- 
possible to  reverse  7  unless  8  is  reversed.  This  is  also  the 
case  with  11  and  10.  Therefore,  if  7  and  9  were  operated 
by  one  lever,  it  would  be  necessary  to  lock  both  the  derail 
and  switch  8  in  both  normal  and  reversed  positions,  with  this 
lever.  The  undesirable  feature  is  this :  If  the  signalman 
started  to  reverse  switch  and  derail  8,  and  the  connections 
between  the  lever  and  derail  should  become  disconnected 
before  the  derail  had  started  to  move,  he  might  complete 
the  reverse  movement  of  lever  8  and  leave  the  derail  open 
without  knowing  it.  He  could  then  reverse  7  (the  plunger 
returning  into  the  same  hole  in  the  derail  lock  rod  from  which 
he  had  just  withdrawn  it),  which  would  permit  him  to  clear 


136 


INTERLOCKING. 


Figs.  750-755 


signal  4.  A  train  from  the  siding  would  then  proceed  and 
be  derailed.  One  spare  space,  5,  and  two  spare  levers,  6  and 
12,  have  been  provided  to  take  care  of  future  changes. 

Such  points  in  the  locking  sheet  (Fig.  747)  as  differ  from 
locking  sheet,  Fig.  742,  will  be  now  explained.  Lever  2  re- 
versed locks  8  and  10  normal:  it  also  locks  9  reversed,  which 


"••I- 6 


by  3  reversed.  Lever  4  reversed  locks  7  reversed,  which  in 
turn  locks  8  reversed;  therefore,  it  is  not  necessary  for  4 
reversed  to  lock  8  reversed  direct  as  It  does  this  indirectly 
through  7. 

As    it    is    possible    to    make    a    movement    from    signal    4    to 
either    the    main    line    or    opposite    siding,    a    special    condition 


MACHINE 

B  LEVERS   FOR   B  SIGNALS 

2  .4  DERAILS 

Z         •  -A   F.P.Ls. 

2  4   CROSSING  BARS 

14  WORKING  LEVERS 
_§_  SPARE  SPACES    5.12 
16   LEVER  FRAME 


F 


REVERSE 

LOCKS 

REVERSE 

LOCKS 

1 

© 

9 

Z 

©-  is 

10 

© 

3 

© 

1 

® 

4 

®-u   ; 

2 

30HRE  SPACE. 

5 

SPARE  SCWCE 

3 

® 

6 

© 

4 

@ 

7 

® 

5 

® 

a 

9 

6 

® 

Figs.    750-753.      Typical    Interlocking   Plan   and    Locking  Sheet;  Single  Track  Crossing,  Showing 

the  Use  of  Crossing  Bars. 


tVlACMIME 


I  SWITCH  AND  7  DERAILS 


££  WORKING  LEVER! 
__E_SF»R£  SPACES 
£4  LEVER  FRAME 


Figs.    754-755- 


Typical    Interlocking    Plan    and    Locking    Sheet;    Single    Track     (with    Turnout) 
Crossing   Double   Track. 


In  its  turn  locks  8  and  10  in  their  normal  and  reversed  posi- 
tions, both  In  the  locking  in  the  machine  and  on  the  ground. 
Lever  3  reversed  does  not  lock  10  reversed  direct,  hut  10  is 
locked  reversed  by  1 1  reversed,  which  In  its  turn  is  locked 


arises   in   connection    with    the    locking.      It   is   evident   that   the 
only    time    that    11    should    be    reversed    is   when    a    movemen 
is   to  be    made    over    10    reversed:    therefore,    the   locking   woul 
read    "4    revcrsod,    when    10    is    reversed,    lo^ks    11    reversed." 


ie 

5 


Figs.  756-758 


INTERLOCKING. 


137 


(See  dog  chart,  Fig.  746,  which  illustrates  this  and  also 
shows  that  11  would  remain  unlocked  with  4  reversed  if  10 
were  normal.) 

When  making  dog  charts  it  is  not  the  practice  to  indicate 
in  full  the  tappet  pieces  (numL-ers  9A,  etc.,  Figs.  859-900), 
as  the  front  dogs  used  in  connection  with  them  indicate  which 


MACHINE 

li  LEVERS  FOR  13  SIGNALS 
S         .  >4  SWITCHES  AND    6  DERAILS 

_7_        •  •      10    F.P.Ls. 

'E3  WORKING  LEVERS 
_i_ SPARE  LEVERS:  a.9,ES.36. 
3Z  LEVER  FRAME 


It  will  be  noticed  that  in  the  Standard*  dog  chart  (Fig. 
746),  levers  2,  3,  4,  13,  14  anii  15  lock  9  reverse},  using 
only  one  bar.  When  combinations  of  this  description  are 
possible  they  simplify  the  locking  by  eliminating  a  number 
of  dogs  and  bars  that  otherwise  would  be  necessary.  If  on* 


igs.   756-757.      Interlocking    Plan    and    Locking   Sheet;   Single   Track   Crossing   Double   Track,   v/ith   Connecting 

Track  and   Crossover. 


33       L-l        30       39       28       27       26       25        24.       23       7-2       il        20         19         18         17        IS        IS        14         IS        13        II         10        3         8 


5 


i 


K 


Hs 


jgr; 


4a-a 


is-ii 


--^ 


%* 


A 


^^ 


^ 


SPARE  BRACKET  ^|f 


'"ig.  758.     Saxby  &    1'armer  Dog  Chart  for  Figs.  755-757- 


tappet  pieces  are  employed.  The  special  on  lever  13  in  con- 
nection with  levers  7  and  8  is  similar  to  the  special  on  lever 
4.  Lever  14  reversed  does  not  lock  8  reversed  direct,  as  8 
is  locked  reversed  by  ~  reversed,  which  is  in  turn  locked  by 
14  reversed.  If  the  lo'cking  sheet  had  shown  14  reversed  lock- 
ing 8  reversed,  it  would  have  been  called  an  "overlock."  This 
is  a  duplication  of  locking  already  accomplished. 


lever  reversed  locks  another  lever  normal  and  reversed;  for 
instance,  9  reversed  locks  8  normal  and  reversed,  the  locking 
should  be  arranged  as  shown  in  the  dog  chart  and  not  sep- 


*See  definition  of  Standard  Interlocking  Machine.  This  ma- 
rhino  is:  referred  to  in  this  manner  throughout  the  entire  de- 
scription. 


INTERLOCKING. 


Figs.  759-763 


arated,  as  shown  in  Figs.  748-749.  The  latter  arrangement 
would  make  It  impossible  to  reverse  9  whether  8  were  normal 
or  reversed.  Regarding  the  arrangement  of  back  locking  in 
the  third  space  of  dog  chart,  Fig.  746,  it  will  be  seen  that  2 
reversed  locks  8  and  10  normal.  The  bar  then  butts  against 
the  top  bar  to  the  right  of  it,  consequently  holding  the  dog 
in  the  notch  of  tappet  15  and  thereby  locking  it  normal. 


chart  for  the  locking  sheet  shown  in  the  figure,  the  best 
method  of  procedure,  after  becoming  familiar  with  the  locking 
sheet,  is  first  to  lay  out  the  locking  for  the  levers  on  which 
specials  occur.  Reference  to  the  locking  sheet  will  show  that 
lever  4  reversed  when  10  is  reversed  locks  11  reversed.  There- 
fore, it  is  advisable  to  place  the  driver  operated  by  lever  4 
on  one  of  the  bars  near  the  top  of  the  chart ;  next  in  order 


I          g          34          5         6          7          8          9          10         II          12         13         II         15         IB         17         18  £    19        £0       21        £2       £3       24       E5       26       £7       28       E9       30       31         32 


m. 


Fig.   759.     Standard  Dog  Chart  for   Figs.  756-757. 


MAGMIIME: 

10  LEVERS   FOR   10  SIGNALS 
Z      .  -3  SWITCHES  AND 

__3_      -  -4   F.P.lS. 

15  WORKING  LEVERS 
_I_SWRE  SWCE:  6 

I  6  LEVER  FRAME      . 


REVERSE 

LOCKS 

REVERSE 

LOCKS 

1 

©® 

9 

10® 

z 

8  @    1?     13    14 

10 

3 

®  10    13 

II 

® 

4 

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12 

© 

5 

©  15 

13 

,0® 

w 

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14 

®@ 

6 

SPARE,   snvct 

15 

8-© 

7 

a  <D 

16 

© 

e 

Figs.    760-761.     Typical   Interlocking   Plan   and    Locking  Sheet;   Single  Track  Junction  with  Double  Track. 


3||2 


MACHINE: 

12  LEVERS  FOR   12  SIGNALS 
4       •  -6  SWITCHES 

2        •  •       S  F.RLs. 

18  WORKINS  LEVERS 

_2_snnRE  LEVERS:  5.1 Z 

£0  LEVER  FRAME 


REVERSE 

LOCKS 

REVERSE 

LOCKS 

1 

© 

W 

9X7 

2 

7-®-9  -II  -1* 

II 

9 

3 

7  -@-  13  -15-  IS 

12 

SPARE  LEVER 

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13 

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w 

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W 

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4 

©-15  -16-18  -19 

14 

H-®-3 

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7X9 

W 

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W 

©  X  ©-I3-I4 

15 

'0-©-®-® 

5 

SPARE  LEVER 

16 

IO-©-9-  7 

6 

7-©-9-(D-IO-® 

17 

© 

7 

18 

©-©-©•© 

8 

7-®-a-®-n-© 

(3 

®-®-9 

9 

20 

1 

10 

Figs.  762-763.     Typical   Interlocking  Plan  and  Locking    Sheet;  Double  Track  to  Four-Track  Junction. 


Furthermore,  when  15  is  reversed  it  locks  10  and  8  normal, 
as  the  first  and  second  bars  are  both  fastened  to  the  same 
dog,  which  locks  lever  10. 

The  combinations  of  locking  used  in  making  the  Saxby  & 
Farmer  dog  chart  (Fig.  745)  as  shown  are  considerably  dif- 
ferent from  those  found  to  give  the  best  results  with  the 
Standard,  this  being  due  to  the  different  construction  of  the 
locking.  When  preparing  to  lay  out  a  Saxby  &  Farmer  dog 


should  come  driver  for  lever  10 ;  then  for  11.  After  the 
drivers  have  been  located  for  levers  4  and  13,  the  special 
locking  for  these  levers  should  be  laid  out.  This  will  then 
give  an  idea  of  where  the  rest  of  the  drivers  should  be  located 
to  give  the  best  results. 

Figs.  764-765  show  typical  signaling  for  the  control  of  a 
double  track  drawbridge.  The  derails  for  high  speed  move- 
ments ore  placed  about  500  ft.  from  the  draw  and  those  for 


Figs. 


INTERLOCKING. 


139 


reverse  movements  about  300  ft.  It  is  advisable,  at  draw- 
bridges, to  control  the  facing  point  locks  and  the  derails  each 
with  a  separate  lever,  as  it  insures  easier  and  somewhat 
safer  operation.  It  is  apparent  that  when  the  draw  is  opened 
the  connections  which  operate  the  various  functions  must  be 
disconnected  to  allow  the  bridge  to  swing.  This  Is  accom- 
plished by  couplers  operated  by  lever  11  which,  when  reversed, 
make  a  through  connection  from  the  levers  to  the  functions. 


bridge  is  closed.  The  action  of  reversing  12  Indirectly  locks 
all  the  derails  In  their  normal  positions.  The  derail  levers 
7,  9,  13  and  15  cannot  be  reversed  until  11  is  reversed,  as 
lever  11  couples  the  connections  operating  the  apparatus,  as 
explained.  It  is  apparent  that  these  connections  should  not 
be  coupled  until  the  rails  are  locked  in  the  proper  position 
for  a  movement  over  them.  Therefore,  11  reversed  locks  10 
reversed  which,  in  its  turn,  locks  12  normal,  preventing  the 


RAIL  LOCKS  . 
COUPLER  U- 


IVIACMIME 


I          '  '     BRIDGE  COUPLERS 

I  •  ••     RAIL   LOCKS 

_[_  STARTING    LEVER:    12 

17  WORKING    LEVERS 

5  SPARE  SPACES     4.5,17 

aO  LEVER   FRAME 


-  *  RAIL  LO 


REVERSE 

LOCKS 

REVERSE 

LOCKS 

1 

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II 

I 

2 

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i 

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i 

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SPAHE  SPACE 

8 

| 

i 

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Figs.    764-765.      Interlocking    Plan   and    Locking   Sheet,   Double  Track  Drawbridge. 


£&& 


*.P.L-e*- 


Hfe 

life- 


REVERSE 

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REVERSE 

LOCKS 

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LOCKS 

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MACHINE: 

13  LEVERS  FOR  13  SIGNALS 
H         .  .       7  SWITCHES  AMJ  I 

_6        •  8F.P.LS. 

£9  WWKIMS   LEVERS 

3  SPARE  LEVERS:  2O.2I.Z9 

4  •       SPACES:  II. 12.^3. Z* 
36    LEVER  FRAME 


Figs.   766-767.     Interlocking   Plan  and   Locking   Sheet,    Crossovers  and  Turnouts  on  Four-Track  Road. 


TftACKJ  

•  •  2^ 

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14^  F.P.L.  IS      17  18  ^^  —  'fV3 

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19  LEVERS  FOR  IB  SIGNALS 

«  .       •    e  SWITCHES 

_4^  .           .       a  F.P.L*. 

CS  WORKING  LEVERS 

«  SPARE  SPACES:IO.II.ZI,22 

Z  .        LEVERS  I £.23 

35"  LTVER  FRAME 


REVERSE 

©<3> 

19  @-S4 

W 

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27 

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28 
29 
30 
31 

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(is>^    X  (ii) 

52, 

(S)KS 

Figs.    768-769.      Interlocking   Plan    and    Locking   Sheet,    Crossovers  on  Four-Track  Road. 


The  rail  locks,  operated  by  lever  10,  are  arrangements  which 
require  the  rails  to  be  in  a  correct  position  for  a  movement 
over  them,  before  the  lever  operating  the  rail  locks  can  be 
reversed,  which,  indirectly,  allows  the  derails  to  be  closed. 
"Starting"  or  bridge-locking  lever  12  is  so  interlocked  with 
the  operating  mechanism  of  the  drawbridge  that  it  is  im- 
possible to  operate  the  draw  until  12  is  reversed,  and  lever 
12  cannot  be  returned  to  its  normal  position  until  the  draw- 


opening  of  the  drawbridge.  Should  a  movement  be  made  from 
signal  2,  over  the  drawbridge,  the  following  procedure  would 
be  necessary  on  the  part  of  the  signalman.  He  would  first 
ascertain  that  12  was  in  the  normal  position  to  insure  that 
the  draw  was  locked.  This  would  allow  him  to  reverse  10. 
thereby  locking  the  rails.  He  could  then  reverse  11,  which 
would  couple  the  connections  and  unlock  derails  7  and  13. 
which  he  could  then  reverse;  next  would  follow  the  reversa. 


140 


INTERLOCKING. 


Figs.  770-779 


of  6  to  lock  7  and  of  14  to  lock  13,  and,  finally,  the  clearing 
of  signal  2.  In  the  figure  illustrated,  the  tower  is  placed 
on  the  drawbridge,  although  this  is  not  necessary,  as  it  may 
be  located  wherever  desired  to  take  advantage  of  circumstances 
or  to  satisfy  special  conditions. 

Several  peculiar  situations  are  illustrated  in  Figs.  772-779. 
Reference  to  Figs.  772-773  shows  that  five  dwarf  signals,  con- 
trolling movements  from  tracks  1  to  5,  inclusive,  are  operated 
by  one  lever.  The  connections  which  operate  these  signals 
are  so  "selected"  through  switches  2,  3,  4  and  5,  that  it  is 
possible  to  clear  only  one  of  the  five  signals  at  one  time.  (See 
Figs.  1021  and  1025.)  For  instance,  when  the  switches  are  set 


in  the  position  shown,  the  reversal  of  lever  1  would  clear  the 
signal  governing  movements  from  track  5  and  lock  switch 
5  in  the  normal  position.  It  would  also  lock  switches  2,  8 
and  4  in  whichever  position  they  were  when  the  lever  was 
reversed. 

There  are  two  methods  of  arranging  the  locking  for  signal  6; 
both  are  shown  on  the  locking  sheet,  one  beneath  the  other. 
The  first  method  requires  that  switches  4,  3  and  2  be  locked 
through  a  series  of  specials,  the  second  method  that  they  be 
locked  direct.  It  is  evident  that  when  the  first  method  is 
used  the  switches  over  which  the  train  is  to  move  are  locked 
when  lever  6  is  reversed.  For  instance,  if  a  train  is  to  make 


MACHINE 


17  LEVERS  FOR   17  SIGNALS 

.6        »  •    •  7  SWTOHES.2M.P.FROGSANP  I  DERAIL 

n  WORKING  LEVERS' 

_^  SPARE  SRACES:9.IO,II,I8.I9. 
28   LEVER  FRAME 


REVERSE 

LOCKS 

REVERSE 

LOCKS 

REVERSE 

LOCKS 

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Figs.    7/0-771.      Interlocking    Plan    and    Locking    Sheet,   Crossovers    on    Four-Track    Road,    Using   Double    Slip 

Switches  with    Movable    Point   Frogs. 


REVEBSe  LOCKS 


W©-4-3    X 


,g__|_5;L®-4.®.3-(3>z-g)_ 

Figs.  772-773- 


Figs.  776-^77- 


Figs.  774-775- 


Figs.  778-779. 


Fig.  772-779.     Interlocking  Plans  and  Locking   Sheets    Illustrating    Special    Conditions. 


in  the  correct  position  for  a  movement  from  one  of  these 
tracks,  then  the  reversal  of  lever  1  clears  the  signal  govern- 
ing movements  from  this  track.  The  other  four  signals  remain 
in  the  stop  position.  Fig.  772  shows  the  switches  set  in  the 
correct  position  for  a  movement  from  track  5.  If  lever  1  is 
reversed  the  signal  controlling  movements  from  track  5  will 
be  cleared.  As  the  various  signals  operated  by  lever  1  govern 
movements  over  switches  2,  3,  4  and  5,  in  their  normal  and 
reversed  positions,  it  is  necessary  for  lever  1  reversed  to 
lock  these  switches  in  both  their  normal  and  reversed  posi- 
tions. It  is  apparent,  therefore,  that  if  the  switches  were 


a  movement  from  signal  6  to  track  5,  then  switch  5  only 
would  be  locked  with  6  reversed,  thereby  allowing  the  signal- 
man to  arrange  switches  2,  3  and  4  in  position  for  another 
movement.  When  the  second  method  is  employed,  the  locking 
is  simplified  by  elimination  of  the  specials,  but  the  action  of 
reversing  lever  6  locks  all  switches  in  whatever  position  they 
may  then  be;  and  consequently  makes  it  impossible  for  the 
signalman  to  alter  the  position  of  any  of  the  switches  pre- 
paratory to  setting  up  another  route  while  lever  6  is  reversed. 
The  point  in  favor  of  the  first  method  is  that  the  operation  of 
the  machine  is  facilitated  to  a  certain  extent,  while  with  the 


Figs.  780-786 


INTERLOCKING. 


141 


ttO 


3 

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£ 

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6 

+ 

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jj 

11 

6  LEVERS  FOR  B  SIGNALS 
I  -      Z  SWITCHES 

J_       "  •      S  F.P.Ls. 

8  WORKING   LEVERS 
3  SPARE    LEVERS:4,9 
2        •.        SPACES  5.8. 
12  LEVER    FRAME 


REVERSE  |          LOCKS 

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Figs.  780-783.     Interlocking  Plan,  Locking  Sheet    and  Dog  Charts;  Crossover  on  Double  Track. 


SOUTH  BOUND  MAIN 


NORTH  BOUND  MAIN 


SPARE  SPACES:  5. II, IS. 


NORTH      BOUND       REVERSE  LEVERS 

ON     N.B.MAIN  DIRECT 

8 

S 

1 

FROM  N.B.     »>      TO  SIDING 

3 

ID 

8 

3 

ON     S.B.     „      REVERSE 

S 

4 

FROM  S.B.     »      TO  N.B.MAIN 

7 

8 

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»      S.B.     »       *.    SIDING 

S 

10 

7 

8 

B  4 

SOUTH     BOUND 

REVERSE  LEVERS 

ON      S.B.  MAIN  DIRECT 

6 

15 

IE 

>_>       N.B.     »      REVERSE 

8 

13 

FROM  N.B.     ,,      TO  S.B.MAIN 

7 

6 

S 

13 

,_,      SIDING  TO  N.B.MAIN 

9 

8 

10 

14 

M       SIDING    ,,   S.B.     M 

7 

E 

9 

S 

1014 

Figs.  784-785.     Typical  Tower  Plan  and    Manipulation  Chart. 


Power  Offerer  fee?     § 


- 

— 


T! 


Powe 


C7 

\k-*-9OOO  '  ---  m-  -55—  -^245^-  £5-  -^fr-SOO  - 
fewer  Opera  feet 


!  ----  >K--£5-  ->K-  -2f  5-  ->«-  -55-  ->K-  -30£?£7 


10    Levers  for  10  Signals 
6    Levers  for  6  Derails 
16     Working  Levers 


4  __ 


£\ 

^  ___ 


|r 
r 


—  Power  Operated 


Fig.   786.     Standard   Interlocking   Plan  for   Single     Track  Crossing  Double  Track.     New  York 

Central  &  Hudson  River. 


142 


INTERLOCKING. 


Figs.  787-789 


VJ     >) 


F 


J 


G 

E 


bfl 

12 
o 


u 

Q 


§, 


«a 

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00 

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00 


R  •«  *e  -j?  *i 


Figs.  79°-794 


INTERLOCKING. 


143 


second   the    locking     Is     considerably     simplified    as     mentioned 
above. 

The  layout  and  locking  shown  in  Figs.  774-775  are  Illustrated 
that  they  may  be  compared  with  Figs.  776-779.  The  locking 
necessary  to  be  explained  in  connection  with  these  figures  Is 
that  occurring  between  signals  1  and  5  (Figs.  776-777)  and 
between  signals  1  and  6  (Figs.  778-779).  In  Figs.  776-777 
lever  1  should  not  lock  5  normal  direct,  as  it  is  possible  to 
make  a  movement  from  signal  1  to  signal  2,  or  from  signal 
1  over  switch  3  reversed  at  the  same  time  that  a  train  is 


moving  from  signal  5  over  switch  4  reversed.  Therefore,  1 
reversed  should  lock  5  normal  only  when  4  is  normal.  Fig. 
778  is  similar,  except  that  dwarf  signal  5  is  added.  This 
signal  makes  it  possible  for  a  train  to  move  from  signal  6  to 
signal  5  while  a  movement  is  being  made  from  signal  1  over 
3  reversed,  and  necessitates  the  following  special  locking  be- 
tween levers  1  and  6  ;  "1  reversed  when  3  and  4  are  normal 
locks  6  normal,"  it  being  apparent  from  the  explanation  given 
that,  if  3  and  4  are  reversed,  two  movements  could  be  made 
at  the  same  time. 


MACHINES 


foot  of  the  latch  rod  4  (see  detail  Figs.  792-793)  is  held  on 
top  of  the  quadrant  9.  The  latch  shoe  7  holds  the  spring  6 
and  the  latch  rod  4  in  position.  It  also  acts  as  a  guide  for 
the.  rocker.  The  rocker  8  is  pivoted  at  the  center  of  the 
quadrant  9.  The  quadrant  also  acts  as  a  guide  for  the  lever 
the  lever  1  and  is  connected  to  the  latch  rod  thimble  3.  This,  1.  To  the  lever  is  bolted  the  lever  shoe  10,  which,  In  its  turn, 
therefore,  imparts  motion,  when  operated,  to  the  latch  rod  4  is  pivoted  on  a  pin  resting  on  the  bottom  girder  14.  The 


THE   SAXBY   AND   FARMER   INTERLOCKING    MACHINE. 

Figs.  790-794  and  846-850  illustrate  a  Saxby  &  Farmer  inter- 
locking machine  assembled.  Figs.  794-845  show  various  details 
of  the  machine.  In  the  following  description  the  numbers 
refer  to  Figs.  790-794.  The  latch  handle  2  is  pivoted  on 


Figs.  790-791.     Saxby  &  Farmer  Interlocking  Machine  Arranged  for  Vertical  Leadout. 


Numbers  Refer  to  List  of  Names  of  Parts  on  Opposite  Page. 

26 


u 

SECTION     A-A. 


Figs.    792-793.      Saxby    &    Farmer    Interlocking 
Machine — Details  of  Latch  Rod  Foot. 


Fig.   794.     Detail  of  Saxby  &  Farmer  Locking. 


and  the  rocker  die  5.  The  latch  rod  thimble  3  is  used  to 
adjust  the  length  of  the  latch  rod  4.  The  rocker  die  5  makes 
the  connection  between  the  latch  rod  and  the  rocker.  The 
latch  spring  6  is  compressed  when  the  latch  handle  2  is 
raised.  Upon  releasing  the  latch  handle,  it  is  returned  to  its 
normal  position  by  the  spring  6,  unless  the  lever  is  between 
the  normal  and  reverse  positions  and,  in  consequence,  the 


back  and  front  tail  levers,  12  and  13,  are  used  to  connect 
the  levers  to  the  apparatus  controlled.  The  bottom  girder 
14  is  used  to  support  the  levers.  Cap  15,  for  the  bottom 
girder  14,  holds  in  position  the  pin  on  which  lever  shoe  10  is 
pivoted.  The  top  plate  16  carries  the  quadrants  9  which  are 
bolted  to  it.  Slots  are  cored  in  this  plate  to  allow  the  levers 
to  extend  through  it.  The  locking  bearing  17  supports  the 


INTERLOCKING. 


Figs-  795-797 


front  rails  21  and  back  rails  22,  which,  in  turn,  act  as  bear-  nccls  the  rocker  8  to  the  locking  shaft  crank  19.  This  crank 
Ings  for  the  locking  shaft  25,  and  as  supports  for  the  locking  is  rigidly  sit  (ached  to  the  locking  shaft  25.  The  locking 
brackets  23  (see  detail  Fig.  794).  The  universal  link  18  con-  bar  driver  20  is  fastened  to  the  locking  shaft  25.  When 


m        ,  UNIVERSAL  LINK 


Figs.  795-797.     Saxby  &  Farmer  Locking. 

Note. — In  Figs.  795  and  796  the  brackets  are  illustrated    without    caps    in    order    to    show    the    locking    more 

clearly. 

Names  of  Parts  of  Saxby  &  Farmer  Locking  Details;  Figs.  795-845. 


1  No.  i  Locking  Dog,  fa"  x  ]/2" 
lA  No.  lA  Locking  Dog,  fa"  x  y2" 

2  No.  2  Locking  Dog,  y2"  x  y*" 

2  A  No.  2  A  Locking  Dog,  y?"  x  y2" 

3  No.  3  Locking  Dog,  %"  x  l/2" 
3A  No.  sA  Locking  Dog,  %"  x  J^" 


4 
5 
6 

7 
8 
9 
ro 
13 
14 
15 
16 
17 
18 
19 
20 
21 
22 
23 
24 
25 
26 
27 
28 
29 


No.  4  Locking  Dog,  fa"  x  l/2" 

./Vo.  5  Locking  Dog,  y2"  x  l/2" 

//o.  6  Locking  Dog,  fa"  x  J^" 

No.  7  Locking  Dog,  */>"  x  i" 

A^o.  8  Locking  Dog,  fa"  x  i" 

JVo.  9  Locking  Dog,  Y\"  x  i" 

A^o.   10  Locking  Dog,  fa"  x  i" 

A^o.  13  Locking  Dog,  fa"  x  i" 

A/To.  14  Locking  Dog,  y2"  x  i" 

A^o.  15  Locking  Dog,  fa"  x  i" 

No.  16  Locking  Dog,  fa"  x  i" 

A^o.  17  Locking  Dog,  fa"  x  i" 

Right  or  Left  Hand  Trunnion 

Rivet,  y^"  x  15/16",  /or  Firing  44  /o  Locking  Bars 

Rivet,   %"  x   11/16",  /o;-   Trunnions 

Rivet,  y^"  x  17/32",  for  •>£"  Locking  Dogs 

Rivet,  %"  x  i  11/32",  /or  ^2"  Locking  Dogs 

7?iYr/,  ^4"  x  i  19/32",  /or  J4"  Locking  Dogs 

Special  Locking  Dog  Guide 

Special  Locking  Dog 


J/owrf  5"te'j»i^  £>o^,  fa"  Thick 
7>/7  /-/awrf  Swing  Dog,  y2"  Thick 
Right  Hand  Swing  Dog,  y2"  Thick 


30  Left  Hand  Swing  Dog,  fa"  Thick 

31  Right  Hand  Swing  Dog,  fa"  Thick      . 

32  Left  Hand  Trunnion 

33  Right  Hand  Trunnion 

34  Left  Hand  Special  Reach  Trunnion 

35  Right  Hand  Special  Reach  Trunnion 

36  Right  Hand  Special  Reach  Dog,   l/2"    Wide 

37  Left  Hand  Special  Reach  Dog,  y,"  Wide 

38  Right  Hand  Special  Reach  Dog,  i"  Wide 

39  Left  Hand  Special  Reach  Dog,  i"  Wide 

40  Pilling  Piece  for  Locking  Bar 

41  Filling  Piece  for  Cross  Locks 

42  Filling  Piece  for  Cross  Locks 

43  Filling  Piece  for  Cross  Locks 

44  Locking  Bar  Driver 

45  Locking  Bar  Driving  Block 

46  Locking  Bar  Driving  Stud 

47  Steel  Pin,  l/s"  x  fa",  for  Fastening  45  to  46. 
47A  Locking  Bar  Driver,  Block  and  Stud  Comp. 

48  Hex.  Bolt  and  Nut,  ^"  x  I  9/16",  for  Making  Splice 

in  Locking  Bars 

49  Cotter  Pin,  3/32"  x  fa",  for  48 
4gA  Locking  Bar,  Splice  Comp. 

50  Locking  Bar,  l/2"  x  fa",  C.  D.  Steel,  Used  for  Longi- 

tudinal Bars 

51  Locking  Bar,  fa"  x  fa",  C.  D.  Steel,  Used  for  Cross 

Locks 

52  Locking  Bar  Driver 

53  Locking  Bar  Driver 


Figs.  798-845 


INTERLOCKING. 


145 


/©  o  ©  I 


I  A 


/©   O 


2A 


O 


3A 


8 


Numbers  Refer  to  List  of  Names  of  Parts  on  Opposite  Page. 


CFI 


X©  o  © 


LJ'J 


13 


14- 


O 


15 


I6 


17 


IS 

O 


I9          20 


21 


22 


fl 


23 


24- 


CO!  ! 

!  bo 

49  A 


27 


K*0 
.X 

— (U 


26 


7T 


28 


: 


31 


30 


O     O 
O     O 


36 -RIGHT  HAND 
37- LEFT      » 


32 


Q 

n 


33 


D 

n 


34 


35 


CJ 


O          O 


51 


38 -RIGHT  HAND 
39 -LEFT     " 


47  A 


Figs.  798-845.     Saxby  &  Farmer  Locking  Details. 


146 


INTERLOCKING. 


Figs.  846-847 


operated  It  drives  the  longitudinal  locking  27.  The  locking 
brackets  23  support  the  longitudinal  locking  27  and  the  cross 
locking  26  (Fig.  794).  The  locking  bracket  caps  24  are 
used  to  hold  the  locking  26  and  27  in  position  (see  detail 
Figs.  795-797).  The  locking  shaft  25  makes  the  connection 
between  the  crank  19  and  the  locking  bar  driver  20.  Fig. 
794  shows  a  perspective  view  of  cross  locking  26  and  longi- 
tudinal locking  27.  A  number  plate  28  is  placed  on  each  lever, 
levers  being  numbered  consecutively  from  left  to  right.  The 


the  latch  rod  foot  has,  by  the  lowering  of  the  latch  handle, 
engaged  with  the  stop  on  the  quadrant.  This  holds  the  lever 
in  position  and  completes  the  throw  of  the  longitudinal  lock- 
ing. When  a  signalman  desires  to  operate  a  lever,  he  raises 
the  latch  handle.  This  imparts  an  upward  motion  to  the 
latch  rod  and  rocker  die  and  gives  the  rocker  one-half  of 
its  full  throw.  The  rocker  transmits  an  upward  motion  to 
the  universal  link.  This,  through  the  medium  of  the  crank, 
turns  the  locking  shaft.  Turning  the  locking  shaft  gives, 


Figs.  846-847.     Outline  of  the   Saxby  &  Farmer   Interlocking  Machine;  Arranged  for  Vertical  Leadout. 


levers  as  shown  in  the  machine  are  said  to  be  in  the  normal 
position.  When  in  the  opposite  position,  they  are  said  to  be 
reversed.  The  locking  shafts  25,  when  operated,  turn  in  bear- 
ings on  the  rails  21  and  22. 

To  convey  a  clear  idea  of  the  operation  of  the  locking  in 
an  interlocking  machine,  it  will  be  necessary  to  give  an  ex- 
planation of  preliminary  latch  locking.  A  lever  in  a  machine 
is  held  in  position  until  the  latch  rod  foot  (Figs. .  792-793) 
has  been  raised  above  the  quadrant,  by  the  raising  of  the  latch 
handle.  Through  the  rocker  and  locking  shaft,  this  move- 
ment of  the  latch  handle  imparts  one-half  of  the  full  throw 
to  the  longitudinal  locking.  This,  in  turn,  actuates  the  cross 
locking  and  locks  all  conflicting  levers  that  before  this  action 
were  unlocked.  It  keeps  locked  all  levers  that  should  remain 
locked,  until  the  lever  is  moved  to  its  opposite  position  anc! 


through    the   locking   bar   driver,    one-half   of    the   throw   to   the 
longitudinal    locking    and    this,    in    turn,    gives    the    full    throw 
to   the  cross   locking.      When   the    lever   is   fully   moved   to   the 
opposite  position,  the  latch  spring  forces  the  foot  of  the  latch ; 
rod    into    engagement   with   the   stop    on    the   quadrant,    thereby 
imparting    the    other    half    of    the    throw    to    the    rocker    and, 
consequently,    to   the    longitudinal    locking.      It   can    readily   be  • 
understood    that    throwing    the    lever    does    not    transmit    any 
motion    to    the    locking    and    that    it    is    impossible    to    release 
a  lever  which  should  not  be  thrown  because   the  latch  cannot  '< 
lie   raised.     As   very    little   power   can   be   applied   to   the  latch  i 
handle,  the  strain  on  the  locking  is  small   compared  with  thati 
in    machines    where   the  locking   Is  actuated   by   the   movement  t 
of  the  lever. 
Figs.    743,    745,   758,   and    781    show   dog   charts    for   Saxby   & 


Fig.  848 


INTERLOCKING. 


147 


Farmer  interlocking  machines.  The  long  horizontal  lines  repre- 
sent the  locking  bars  and  are  numbered  in  the  order  in  which 
they  are  placed  in  the  machine,  commencing  with  the  one  next 
to  the  levers.  A  small  circle  drawn  on  this  line  shows  by 
which  lever  the  bar  is  worked  and  where  the  connection  is 
made.  Locking  brackets  are  numbered  to  correspond  with  the 
levers.  Cross  locking  is  stamped  with  the  number  of  the 
bracket  in  which  it  is  to  be  placed.  It  is  also  stamped  at  each 
end  with  the  number  of  the  locking  bar  under  that  end.  This 


for  as  many  dogs  as  there  are  levers  to  be  locked.  (See  Fig. 
795,  bracket  G.)  Reversal  of  the  locking  lever  forces  the 
cross  locking  over  against  the  dogs  of  the  other  levers  and 
locks  them.  If  one  of  the  other  levers  has  been  reversed,  the 
cross  locking  will  strike  against  the  dog  of  that  lever  and 
prevent  the  lever  from  being  reversed. 

Special  locking  is  shown  at  30,  bracket  II,  in  Fig.  795.  This 
is  used  when  one  lever  is  to  lock  a  second  lever  only  when  a 
third  lever  is  in  a  given  position.  It  consists  of  a  dog  of 


Fig.   848.      Outline   of   the    Saxby    &   Farmer   Interlocking   Machine; 
Arranged   for    Horizontal    Leadout. 


is  done  in  order  that  the  bars  and  cross  locking  may  be  easily 
replaced  in  the  machine  if  they  have  been  removed  for  any 
reason.  The  cross  locking  is  represented  as  being  placed  close 
to  the  dog  by  which  the  locking  is  performed;  the  clearance 
necessary  to  allow  it  to  be  moved  is  left  next  to  the  other 
dog.  This  is  done  m  order  to  facilitate  reading  of  the  dog 
chart  by  showing  which  lever  does  the  locking,  When  one 
lever  locks  two  or  more  levers  the  cross  locking  is  notched 


special  form  pivoted  on  the  locking  bar  so  that  it  can  be 
moved  sidewise  by  the  two  pieces  of  cross  locking  between 
the  edges  of  which  it  projects.  It  also  moves  lengthwise  with 
the  longitudinal  bar  to  which  it  is  pivoted.  In  the  position 
shown  the  two  pieces  of  cross  locking  act  as  one.  as  the 
clearance  space  between  them  is  taken  up.  If  the  special 
swing  dog  is  withdrawn  it  will  allow  either  of  the  two  pieces 
of  cross  locking  to  be  moved  and  the  first  and  second  lever 


148 


INTERLOCKING. 


Figs.  850-854 


INTERLOCKING. 


149 


reversed    regardless    of    each    other,    and    if    both    are    reversed, 
the    lever    which    carries    the    swing   dog    is    locked. 


THE    STANDARD    INTERLOCKING    MACHINE. 

As  many  of  the  parts  of  the  Standard  machine  (Figs.  851- 
902)  are  similar  to  those  of  the  Saxby  &  Farmer  (Figs. 
790-850),  such  parts  only  as  are  different  will  be  explained. 
The  latch  block  and  roller  (see  detail  Figs.  853-854),  do  the 
same  work  as  the  foot  of  the  latch  rod  and  the  rocker  die 
in  the  Saxby  &  Farmer  machine.  The  latch  block  6  is  also 
used  to  adjust  the  length  of  the  latch  rod.  The  segment  7  is 
of  slightly  different  design,  but  performs  the  same  function 
as  the  quadrant  used  with  the  Saxby  &  Farmer  machine.  The 


the    front    locking.      The    locking    plate    strip    23    is    placed    in 
front  of  the  front  locking  to  hold  it  in  place. 

The  operation  of  the  Standard  machine,  which  accomplishes 
practically  the  same  results  as  that  of  the  Saxby  &  Farmer, 
is  as  follows :  When  the  signalman  desires  to  operate  a 
lever,  he  first  raises  the  latch  handle,  which,  In  its  turn, 
raises  the  latch  rod  and  latch  block  and  compresses  the  latch 
spring  (Figs.  853-854).  This  releases  the  lever  and  at  the 
same  time  gives  the  rocker  one-half  of  its  throw.  The  rocker 
transmits  its  throw  through  the  connecting  link  to  the  tappet 
and  locking.  When  the  lever  has  been  moved  to  the  opposite 
position,  the  latch  spring  forces  the  latch  block  into  engage- 
ment with  the  stop  on  the  segment,  and  It  thus  imparts  the 


Figs.  851-852.      Standard    Interlocking    Machine. 

other  half  of  the  throw  to  the  rocker,  and,  consequently,  to 
the  tappet  and  locking.  The  locking  plates,  which  are 
attached  to  and  supported  by  the  machine  legs,  are  constructed 
with  four  separate  spaces  for  locking.  The  upper  space  Is 


ROLLER 

ROLLER 

Figs.  853-854.     Standard  Interlocking  Machine;  Details 
Fig.   850.     The   Saxby   &    Farmer    Horizontal    Leadout.  of    Latch    Block- 

Names  of  Parts  of   Standard   Interlocking   Machine; 
Figs.   851-854. 


rocker  8  has  a  lug  cast  on  one  end  which  extends  through 
and  above  the  segment,  upon  which  the  signalman  may  press 
with  his  foot,  and  thus  with  less  effort  raise  the  latch  handle 

2.      The   rocker    guide    9,    which    is    riveted    to    the    lever,    acts  I 

as  a  guide  for  the  rocker.     The  back  and  front  girders  10  and  2 

11,    respectively,    support    the   segments.      The   back    girder   also  3 

acts   as   a  stop  for   the   levers.      The  tappet   connecting  link   17  4 

connects   the  rocker  8  to  the  tappet  19.     The  tappet  jaw  18  is  5 

rigidly    screwed   to   the   tappet   19,   which   directly   actuates    the  6 

back   and   front   locking,    24    and   25    (also   see  detail   Figs.    855-  7 

858).       The    locking    plate    21    supports    the    back    and    front  8 

locking    24    and    25    and    guides    the    tappets    19.       The    back  9 

locking  2-4  is  placed  in  the  same  plane  as  the   tappets   between  10 

which    this    locking    is    accomplished.      The   front    locking    23   is  n 

placed  in   front  of  the  back   locking.     The  front  locking  guides  \y. 

22  are  screwed   to   the   locking  plate    21,    to   support   and  guide  13 


Lever 

Latch  Handle 
Latch  Rod 
Latch  Shoe 
Latch  Spring 
Latch  Block 
Segment 
Rocker 
Rocker  Guide 
Back  Girder 
Front  Girder 
Machine  Leg 
Lever  Shoe 


14  Cap 

15  Back  Tail  Lever 

1 6  Front  Tail  Lever 

17  Tappet  Connecting  Link 

18  Tappet  Jaw 

19  Tappet 

20  Top  Plate 

21  Locking  Plate 

22  Front  Locking  Guide 

23  Locking  Plate  Strip 

24  Back  Locking 

25  Front  Locking 

26  Number  Plate 


150 


INTERLOCKING. 


Figs.  855-858 


JX 

s 

be 

C 

°J2 

u 

o 


Figs.  859-900 


INTERLOCKING. 


31 


32 


37  3S  39  40  41 

Figs.  859-900.     Standard   Locking  Details. 
Names  of  Parts  of  Standard  Locking  Details;  Figs.  855-901. 


42 


1  No.  I  Front  Locking  Dog 

2  No.  2  Front  Locking  Dog 

3  No.  3  Front  Locking  Dog 

4  N'o.  4  Front  Locking  Dog 

5  A:o.  5  Front  Locking  Dog 

6  No.  6  Front  Locking  Dog 

7  No.  ~  Front  Coupling  Dog 

8  No.  8  Special  Swing  Dog 
gA  No.  gA   Tappet  Piece 

gB  No.  gB  Tappet  Piece 
loA  No.  loA   Tappet  Piece 
loB  No.  loB  Tappet  Piece 

11  No.  ii   Tappet  Piece 

12  No.  12  Tappet   Piece 

13  No.  13  Back  Locking   Dog 

14  No.   14  Back  Locking  Dog 

15  No.  15  Back   Locking   Dog 

16  No.  16  Back   Locking   Dog 

17  No.  17  jBflc£  Coupling  Dog 

18  JVo.  18  ZJacfc  Carrier  Dog 
ig     Aro.  19  Back  Carrier  Dog 

20  Aro.  20  Front  Locking  Dog 

21  No.  21  Front  Carrier  Dog 

22  No.  22  Front  Locking  Dog 
25     No.  25  Front  Locking  Dog 


26  No.  26  Front  Locking  Dog 

27  No.  27  Front  Locking  Dog 

28  No.  28  Front  Locking  Dog 

29  No.  29  Front  Locking  Dog 

30  No.  i  Front  Locking  Guide 

31  No.  2  Front  Locking  Guide 

32  No.  3  Front  Locking  Guide 

33  No.  4  Front  Locking  Guide 

34  Special  Stud  for  Use  with  30 

35  Special  Stud  for  Use  with  32 

36  14/24  x  il/$,"  Round  Head  Machine  Screw  for  Fas- 

tening Front  Locking  Guides  30,  31,  32  and  33  to 
Locking  Plate 

37  14/24  x  Y%"  Machine  Screw  for  Use  with  34  and  35 

38  14/24   x   y±"   F Ulster  Head  Machine  Screw  for  Fas- 

tening Tappet  Pieces  to  Tappet 

39  10/32  -x  13/16"  Flat  Head  Machine  Screw  Used  for 

Fastening  Front  Lock  Dogs,  Couplers  and  Car- 
riers to  Locking  Bar  42. 

40  10/32  x  15/16"  Flat  Head  Machine  Screw  Used  for 

Fastening  Back  Locking  Dogs,  Couplers  and  Car- 
riers to  Locking  Bar  42 

41  Stud  for  Fastening  and  Pivoting  Special  Swing  Dog 

8  on   Tappet 

42  Locking  Bar 


152 


INTERLOCKING. 


Figs.  901-902 


Fig.   901.      Diagram    of   Standard   Locking    Details  Assembled.      A    Portion    of   This    Locking   is    Shown    in 

Figs.  855-858. 

known  as  space  1,  the  next  as  space  2,  and  so  on.  Two  tiers 
of  locking  may  he  placed  in  each  space,  the  back  tier  being 
called  the  back  locking  and  the  front  tier  the  front  locking 
(966  Sections  A-A  and  B-B,  Figs.  855-858),  4-F  and  4-B  (Sec- 
tion B-B)  designate  "The  4th  space,  front  locking,"  and  "The 
4th  space,  back  locking,"  respectively.  This  section  also 
shows  the  relative  positions  of  the  front  and  back  locking  dogs 
and  locking  bars.  It  is  possible  to  place  three  bars,  side  by 
side,  in  the  space  provided  for  the  back  locking  bars,  and  five 
bars,  side  by  side,  In  the  space  provided  for  the  front  locking 
bars  (see  Section  A-A,  showing  two  back  locking  bars  and  three 
front  locking  bars). 

The  mechanical  construction  of  the  locking  Is  that  of  a  bar 
or  tappet  locked  by  a  dog  moving  at  right  angles  to  It  and 
fitting  In  a  notch  cut  in  the  edge  of  the  tappet.  For  Instance, 
the  two  adjacent  levers  6  and  7,  Fig.  901  (space  2B),  are  inter- 
locked by  the  dog  13,  which  Is  made  longer  than  the  space 
between  the  two  tappets.  Thus  one  tappet  will  be  free  to  > 
move  only  when  the  dog  slides  into  the  notch  cut  in  the  other. 
Unless  the  notch  in  the  second  bar  Is  In  a  position  to  allow 
the  dog  to  be  forced  over,  the  tappet  is  locked  and  the  lever 
cannot  be  moved.  When  the  two  levers  to  be  interlocked 
are  not  next  to  each  other,  the  dogs  are  connected  together 
h.v  a  small  locking  bar  42  (Figs.  859-900),  as  shown  between; 
tappels  12  and  14  (space  IB),  Figs.  855  and  901. 

The  dogs  consist   of  tapered   pieces   of  steel    (1-6,   13-16,  20, 
and  25-29,  Figs.   859-900).     In  the  c&se  of  front  locking,  small  ; 
lugs,    known    as    tappet    pieces    (9A-12)    are    fastened    to    the' 
tappets    and    the    dogs    strike    against     these    as     they    would 
against   the   side   of  the  notch   In   back   locking.      Special   lock- 
ing is   employed  as  In  the   Saxby  &  Farmer  machine.     In  this 
case    the    special    consists    of    a    swing    dog    8    pivoted    to    the 
tappet.     In   other  types   of  machines  of  this  class,   the  special 
Is  usually  a  block  sliding  in  a  notch  in  the  tappet. 

If    necessary    a    locking    plate    may    also    be    placed    on    the 
opposite  side  of  the   machine  legs  beneath   the  front  tall   lever! 
(16,  Fig.   851),  and  tappets  connected  to  the  eye  In  the  front 
end   of  the   rocker. 

A  dog  chart  for  a  standard  machine  is  shown  In  Figs.  74t 
and  746.  For  the  sake  of  clearness  the  front  and  back  locking, 
for  a  given  space  Is  grouped  as  shown.  Where  front  locking 
is  shown  (Fig.  746)  the  tappet  pieces  are  shown  only  by  lines 
representing  their  active  faces. 


Fig.    902.      Standard    I  iitrrlnokin.e:    Machine. 


T1IK    JOHNSON     INTERLOCKING    MACHINE. 

This    machine     (Figs.     903-932)     differs    from    others    of    the 
vertical   locking   type   In    that   the   tappet   moves   upward   whet ! 
the    lever    Is    being    reversed,    instead    of   downward;    also,    th*> 
rocker  is  nl Inched  to  a  bracket  which  Is  rigidly  connected  to  the 
lever  and,  therefore,  moves  with  It,  the  connection  between  th» 
rocker  and   lappet    having  only  a   vertical  motion.     The  locking 
dogs,   etc.,   used   in   this  machine  are  similar   to   those  used  lr 
the    National    machine    (Figs.  .936-1003),   and    to    those   used   lr 
the    hack    Licking    of    the    Standard    machine     (Figs.    859-900) 
I'rollminnry   hitch  locking  is  a  feature  of  this  machine. 


Figs.  903-931 


INTERLOCKING. 


153 


/\ 

7 

V 


LJ 


2 


I 
V 


n 


V 

r~i 

10 


V 
/\ 


9 

V 


8 
V 


15 
o 

V 


14  o 

o 
o 
o 

V 
FT 


13 

V 


12 


16 

V 


LZI 

20 


25 


_23/\ 


/\22 


17 


26 


21 

V 


Fig.   903.      Johnson    Locking. 


Figs.   904-929.     Johnson   Locking   Details. 


i  to  21     Locking  Dogs 

22  Special  Locking  Dog 

23  Locking  Dog 


Names  of  Parts   of  Johnson  Locking  Details;   Figs.  904-929. 

24  Spacing  Strip 

25  10/32"  x  I/*'  Special  Steel  Screzu  for  Locking  Dogs 

26  Y&"  x  $i"  Steel  Locking  Bar 


Figs.    930-931.      Johnson    Interlocking    Machine. 


154 


INTERLOCKING. 


Figs.  932-935 


THE    NATIONAL    INTERLOCKING    MACHINE. 

This  machine  (Figs.  933-1003)  is  somewhat  similar  in  do  sign 
and  operation  to  the  Standard ;  the  lever,  the  latch  handle 
and  its  connections,  the  rocker  and  the  link  connecting  it 
to  the  tappet  vary  only  slightly  in  design.  Locking  plates 
are  often  provided  on  both  sides  of  the  machine  legs  and 
operated  as  in  the  Standard  machine.  The  type  of  locking 
used  is  similar  to  that  used  in  the  Johnson  machine  and  to 
the  back  locking  in  the  Standard,  although  a  greater  variety 
of  dogs  is  necessary  to  secure  the  same  results. 


Fig.    032.      The    Johnson    Interlocking    Machine. 


Names  of  Parts;  Fig.  934. 

S     Link 
R     Rocker 
T     Tappet 
P    Latch  Rod 


I'i.g-    933-      The    National    Interlocking    Machine. 
1         2        34        5        6        78        910       11       12 


C 

c 


Fig.  934.    The  National  Inter- 
locking  Machine,    End 
Elevation. 


x~iw 


Et 


I  (aatlasJ* 


0 


Fig-  935-     Typical  Diagram  of  Locking  for  a  National  Machine. 


Figs.  936-1003 


INTERLOCKING. 


155 


\y 


D 


QQ    Q 
PQ    Q 


m  00 


n 
I 


Figs.  936-1003.     National    Locking   Details. 


156 


INTERLOCKING. 


Figs.  1004-1006 


Fig.  1005.     Style  "C"  Interlocking  Machine 


Fig.    1004.     Dwarf  Interlocking  Machine. 
Signal  Company. 


The  Unicn  Switch  & 


DWARF    INTERLOCKING    MACHINE. 

Fig.  1004  illustrates  what  is  known  as  the  Dwarf  Inter- 
locking Machine.  Dwarf  machines  are  designed  for  use  at 
outlying  switches  and  on  elevated  railroads,  where  they  may 
be  set  on  ties  or  on  low  platforms  at  track  level.  They  can 
also  be  used  instead  of  the  Stevens  or  Style  "C"  machine, 
except  where  a  vertical  leadout  is  necessary.  The  dwarf 
machines  are  made  without  preliminary  locking,  and  therefore 
are  without  the  quadrants,  universal  links  and  locking  bed 
attachments  required  where  the  refinement  of  latch-locking  is 
necessary  as  in  the  types  of  machines  shown,  on  the  preceding 
pages. 


STEVENS    INTERLOCKING    MACHINE. 

The  Stevens  interlocking  machine  is  shown  in  Fig.  1006.  It 
la  designed  to  work  and  control  a  small  number  of  switches 
and  signals  at  points  where  the  space  for  installing  a  ma- 
chine is  limited  or  where  It  is  found  advantageous  to  control 
a  number  of  yard  switches  from  a  central  point.  It  can  he 
operated  on  the  ground  level  with  horizontal  connections,  or 
can  be  set  on  a  platform  and  be  vertically  connected.  This 
type  of  machine  is  made  without  preliminary  latch  locking. 

STYLE    "C"    INTERLOCKING    MACHINE. 

The  Style  "C"  interlocking  machine,  shown  in  Fig.  1005,  !s 
similar  in  design  to  the  Stevens  and  is  also  intended  for  use 
where  it  is  desired  to  control  a  number  of  units  in  a  yard  as 
from  a  location  at  grade  where  it  is  not  always  feasible  to  con- 
struct a  tower. 


Fig.    1006.     The   Stevens  Interlocking  Machine. 


Figs.  1007-1010 


INTERLOCKING. 


157 


MECHANICAL  INTERLOCKING  PARTS  AND  DETAILS  OF  CONSTRUCTION 


LEADOUTS. 

The  leadout  or  arrangement  of  apparatus  by  which  the  oper- 
ating connections  are  carried  from  the  machine  out  of  the 
tower  consists  of  a  foundation  or  platform  forming  an  exten- 
sion of  the  tower  floor  and  the  leadout  devices  which  are 
mounted  thereon.  These  may  consist  of  deflecting  bars,  Figs. 
1007-1009,  rocker  shafts,  1010-1015,  box  cranks,  1016-1020,  or 
any  combination  of  the  three.  The  rockers  may  be  inverted 


where  clearances  demand  (Fig.  1010).  Rocker  shafts  are  made 
of  hexagonal  or  square  steel  bars  mounted  in  bearings  (Figs. 
1283-1285).  They  carry  arms  to  which  the  vertical  rods  and  pipe 
lines  are  attached.  A  box  crank  is  a  frame  in  which  a  number 
of  cranks  are  mounted  (Figs.  1152-1158).  A  box  crank  leadout 
requires  more  space  than  a  rocker  shaft  leadout,  but  is  more 
accessible.  Where  box  cranks  are  used  the  vertical  rods  must 
be  attached  to  vertical  cranks. 


=^fe= 

• 

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'If 

JMB 

jH 

1* 

Iff 

SP 

Iff 

Iffi 

U£ 

N0 

PF 

If" 

IB 

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$  H    H     f 

M 

3 

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,JM^, 

Tu"MPh-  !A-  !          1       1^-  IA-  li—  !<£-  1A-  IA— 

1    1 

i^l     1          I—AI-AI-A!  -^  —A!  -a,!     !          1  -AJ     .Igl  AT" 

jJloL 

Figs.    1007-1009.     Layout    Showing    Deflecting    Bar    Leadout. 


Fig.   1010.     Inverted  Rocker  Shaft   Leadout  and  Double-Deck  Pipe  Line.     Delaware,    Lackawana  &  Western. 


158 


INTERLOCKING. 


Figs.  1011-1015 


Figs.    1011-1015.     Layout  Showing   Saxby  &  Farmer   Interlocking   Machine   in   Cabin,    Rocker    Shaft    and    Box 

Wheel  Leadout. 


Figs.  1016-1020 


INTERLOCKING. 


159 


Figs.    1016-1020.     Layout  Showing  Saxby  &  Farmer  Interlocking   Machine   in   Cabin,  with   Box  Crank  and  Box 

Wheel  Leadout. 


i6o 


INTERLOCKING. 


Figs.  1021-1025 


S^gnaJ  Lerer 


MAINLINE.    Pa&senger? 


/  M  \ 

tram 

D    C    B    A 


MAINLINE.        Frei^fii. 


«  D 


B 


Fig.  1021.     Track  Diagram  Showing  Application  of    Selector   Illustrated    in    Fig.    1025. 


TWO    LEVERS    OPERATING    A   THREE-POSITION    SIGNAL. 

Figs.  1022-1024  show  how  a  three-position  signal  may  be 
operated  by  two  levers  and  one  pipe  line.  A  floating  lever  is 
Introduced  between  the  two  machine  tall  levers,  and  to  this 
the  pipe  line  is  attached.  The  illustration  shows  the  position 
of  the  apparatus  corresponding  to  each  position  of  the  signal. 


SIGNAL  LEVER 


(  SWITCH  LEVERS 

U 


Figs.    1022-1024.    Method   of   Operating   a   Three-Position 
Signal   from   Two   Levers.     Baltimore    &   Ohio. 

SELECTORS. 

Several  signals  may  be  operated  from  one  lever  by  means  of 
selectors,  the  signal  cleared  depending  upon  the  position  of  the 
various  switches.  Figs.  1025  and  1021  show  a  perspective  view 
of  a  four-hook  tower  selector  and  a  track  diagram  showing 
its  application.  The  signals  are  wire  connected.  The  pull 
wires  are  attached  to  hooks  in  the  selector,  all  of  which, 
except  that  to  arm  A,  are  normally  disengaged  from  the  dog 
at  the  end  of  the  rod  operated  by  lever  No.  1.  When  switch 
4  is  reversed  A  is  disengaged  and  B  is  engaged  by  the  action 
of  the  cam  on  the  shaft  actuated  by  lever  4.  When  3  and 
4  are  both  reversed  B  is  disengaged  and  C  engaged.  Reversal 
of  2,  3  and  4  disengages  C  and  engages  D.  A  similar  arrange- 
ment can  be  used  with  pipe  connected  signals. 


Fig.  1025.     Wire  Connected  Cabin  Hook 

Selector.     The  Union  Switch  & 

Signal  Company. 


Figs.   1026-1046 


INTERLOCKING. 


161 


PIPES    AND    COUPLINGS. 

The  connections  between  the  lever  of  the  Interlocking  ma- 
chine and  its  function,  through  which  the  motion  is  imparted, 
consist  of  one  in.  iron  pipe  or  No.  9  gage  steel  wire.  Wire  is 
used  for  signals  only.  Lengths  of  pipe  are  joined  together  or 
to  jaws  by  coupling  sleeves  and  rivets  through  iron  plugs 
cr  through  the  tang  end  of  the  jaw.  Thus  a  rigid  joint  is 
secured  which  does  not  depend  on  the  threads.  Various  pipe 
and  rod  connections  and  adjustments  are  shown  in  Figs.  1026- 
1024  and  1047-1121).  The  butt  or  "stub"  ends  are  provided 
for  welding  to  solid  rods. 

Following  are  R.  S.  A.  specifications  for  one-inch  pipe  and 
couplings : 

PIPE. — 1.  Pipe  must  be  soft  steel  straight,  tough  and  uniform 
in  quality;  free  from  cinder  pockets,  blisters,  burns  and  other 
injurious  flaws.  Must  be  hot  galvanized  inside  and  outside,  un- 
wiped. 


accepted   weighing   less   than    1.63   pounds    per   foot,   weight  of 
coupling  not  included. 

5.  The   outside   diameter   of   pipe   must   conform    to    Briggs' 
Standard.     Any  pipe  enough  less  than  1.31  Inches  in  diameter 
to  result  in  flat  thread  will  be  rejected. 

6.  The    manufacturer   shall    furnish   all  necessary    facilities 
for  making  tests  and  the  tests   shall  be  made  at  the  mill. 

7.  Inside    diameter    of    all    pipe    must    be    large    enough    to 
receive  a  hardened  steel  plug  of  63-64  inch  diameter  for  a  length 
of  six  inches. 

8.  Not  more  than  one  per  cent,   of  pipe  less  than  15  feet 
long  will  be  accepted,   lengths  of   17   feet  and  over   being  pre- 
ferred. 

9.  The    ends   of   pipe   must    be   cut   square   and   drilled    for 
two    %-inch   rivets   on  one  end   only;  first   rivet  hole  shall  be 
drilled   two    inches   from    the   end   and    the   second    two    inches 
from  this  and  at  right  angles  to  it. 


S/snJarc/ /Rpe         H—  /H  H- /%'-* 

A\  If  _  II 


/"Pipe  Tftreac/.  //#  'fareec/s  ftr /" 


Pipe  Joint   Complete. 


-+X 


•     /"  * 

k             °"           H 

* 

•< 

< 

> 

fl 

\           n       /* 

Go/  M//~ot/gSif  Srosi 

Coupling. 


\~s 

Rivet. 


Lug   and   Tang   Ends. 


Wire  Adjusting  Screw. 


7AMG  £H0.  /X"/VUT. 

Screw  Jaw    (Tang   End). 


Pipe   Adjusting  Screw. 


Straight    Adjustable    Link.  Jaw  Pins.  Solid   Link. 

Figs.    1026-1046.     Railway    Signal    Association    Standards. 


2.  The  tensile  strength,  limit  of  elasticity  and  ductility  shall 
be  determined  from  a  test  piece  cut  from  finished  pipe. 

3.  The  pipe  shall  have  a  tensile  strength  of  not  less  than 
52,000  pounds  per  square  Inch,  and  an  elastic  limit  of  not  less 
than  30,000  pounds  per  square  inch,  and  an  elongation  of  not 
less   than   18  per  cent.    In  a   measured  length   of  eight  inches. 
All  pipe  must  stand  a  test  of  600  pounds  per  square  inch  inter- 
nal hydrostatic  pressure  without  leak. 

A  piece  of  pipe  one  foot  long  will  be  selected  at  random 
and  be  subjected  to  a  flattening  test  by  hammering  the  piece 
until  the  opposite  sides  are  within  twice  the  thickness  of  the 
wall  from  each  other;  ine  piece  shall  show  no  cracks  in  the 
•teel  except  at  the  weld. 

4.    The    weight    of    one    foot    of    one    Inch    pipe    before    gal- 
vanizing should   be   1.71   pounds,   and   In  no  case  will   pipe   be 


10.  Each  length  of  pipe  shall  have  a  thread  1%-inch  long, 
%-inch  total  taper  per  foot,  11%  slightly  round  top  and  bot- 
tom "V"  threads  to  the  inch.  The  threaded  portion  of  the  pipe 
shall  be  of  such  diameter  as  to  admit  the  coupling  to  be  screwed 
on  five  turns  by  hand,  with  a  permissible  variation  of  one  turn 
either  way. 

COUPLINGS. — Pipe  couplings  must  be  galvanized,  must  be  2% 
inches  long  and  1%  inches  outside  diameter,  of  wrought  iron, 
free  from  defects,  faced  at  ends,  tapped  straight  through,  pitch 
diameter  of  thread  to  be  such  as  to  fit  pipe  as  per  section  10 
above,  1.26  inches,  varying  not  more  than  .003  of  an  inch. 

PLUGS. — Plugs  must  be  merchant  bar  steel,  10  Inches  long,  31- 
32  inch  In  diameter,  drilled  for  four  14 -inch  rivets  with  drill 
.256: 


1 62 


INTERLOCKING. 


Figs.  1047-1121 


O       Jl  2         13         14         15        16       17 


I 
2 

3 
4 
5 
6 

7 
8 

9 
10 
ii 

12 
13 
14 
15 

16 

17 
18 

19 

20 
21 
22 
23 
24 


30       31         32        33       34        35 


59       6O       61  65        66      67 


Figs.   1047-1121.     Jaws,   Pipe  Lugs,  and  Links. 


Names  of  Parts; 

Tang  End  Wide  Jaw,  i%-in. 

Threaded  End  Wide  Jaw,  i%-in. 

Butt  End  Wide  Jaw,  1%-in. 

Tang  End  Slotted  Jaw,  il/^-in. 

Threaded  End  Slotted  Jazv,  ij^-tn. 

Butt  End  Slotted  Jaw,  i%-in. 

Tang  End  Transition  Jaw,  i%-in.  to  i-in. 

Tang  End  Jazv,  ity-in. 

Tang  End  Transition  Jaw,  i-in.  to  i%-in. 

Threaded  End  Jaw,   iV^-in. 

Butt  End  Jaw,  i!/£-in. 

Tang  End  Transition  Jazv,  i%-in.  to  i-in. 

Tang  End  Jaw,  i-in. 

Threaded  End  Jaw,  i-in. 

Butt  End  Jaw,  i-in. 

Threaded  End  Jaw,  y^-in. 

Butt  End  Jaw,  Y^-in. 

Threaded  Up  and  Down  Rod  with  Jaw,  Y^-in. 

Butt  End  Up  and  Down  Rod  with  Jazv,  l/2-in. 

Up  and  Down  Rod  with  Plain  and  Screw  Jaw,  y2~in. 

Tang  End  Lug 

Butt  and  Tang  End  Lug 

Threaded  and  Tang  End  Lug 

Threaded  Up  and  Down  Rod  zvith  Screw  Jaw,  r/>-in. 


Figs.   1047-1121. 

25  Butt  End   Up  and  Down  Rod  zvith  Screw  Jaw, 

26  Threaded  End  Lug 

27  Butt  and  Threaded  End  Lug 

28  Butt  End  Lug 

29  Tang  End  Clevis  Nut,  i%-in. 

30  Tang  End  Transition  Screw  Jazv,  i%-in.  to  i-in 

31  Tang  End  Screw  Jaw,   \V±-in. 

32  Tang  End  Transition  Screw  Jaw,  i-in.  to  i^-i 

33  Threaded  End  Screw  Jazv,  1%-in. 

34  Butt  End  Screzv  Jazv,  1%-in. 

35  Tang  End  Transition  Screw  Jaw,  i%-in.  to  i-in. 

36  Tang  End  Screw  Jazv,  i-in. 

37  Threaded  End  Screw  Jaw,  i-in. 

38  Butt  End  Screw  Jaw,  i-in. 

39  Threaded  End  Screzv  Jaw,  y^-in. 

40  Butt  End  Screw  Jazv,  y^-in. 

41  Gain  Stroke  Jazv  with  Plain  Jaw,   1%-in. 

42  Gain  Stroke  Jaw  zvith  Screw  Jaw,  i%-in. 

43  Tang  End  Stroke  Jaw,  1%-in. 

44  Butt  End  Jaw,  ij4-in. 

45  Tang  End  Threaded  Rod,  i^-in. 

46  Tang  and  Butt  End  Double  Jaw,   il/4-in. 

47  Tang  End  Double  Jaw  zvith  Eye,  l^-in. 

48  Double  Jaw  zvith  Two  Eyes,  1%-in. 


y2-in. 


Figs.  11-22-1133 


INTERLOCKING. 


163 


49  Threaded  End  Double  Jaw  with  Eye, 

50  Butt  End  Double  Jaw  with  Eye,  i%-i 

51  Butt  and  Threaded  End  Double  Jaw, 

52  Butt  End  Double  Jazv,  i%-in. 

53  Threaded  End  Double  Jaw,  il/^-in. 

54  Tang  End  Double  Jazv,  1%-in. 

55  Tang  and  Threaded  End  Double  Jaw, 

56  Tang  End  Jazv,  1%-in. 

57  Threaded  End  Jaw,  i%-in. 

58  Butt  End  Jazv,  1%-in. 

59  Tang  End  Screw  Jazv,  i%-in. 

60  Threaded  End  Screw  Jaw,  i%-in. 

61  Butt  End  Screzv  Jazv,  1%-in. 


\Y\-in. 


62 
63 
64 
65 
66 
67 
68 
69 
70 
71 
72 
73 


Offset  Jaw,   1%-in. 
Threaded  End  Offset  Jaw,   1%-in. 
5«^  End  Offset  Jaw,  il/4-in. 
Tang  End  Offset  Screzv  Jaw,  1%-in. 
Threaded  End  Offset  Screw  Jaw,  1%-in. 
Butt  End  Offset  Screw  Jaw,  1%-in. 
Adjustable  Link,  1%-in. 
Solid  Link,  i%-in. 
Solid  Link,  1%-in. 
Solid  Link  with  Slotted  Jaw,  i%-in. 
Adjustable  Link  with  Slotted  Jaw,  1%-in. 
Clamp  Pipe  Lug 


Solid    Jaw    (Butt    End). 


,1 


Screw  Jaw.      r — '•£— 


Straight    Solid    Jaw    (Tang    End). 


5 

5 

i 

3 

•« 

s\ 

.1 

<t 

\ 

^ 

! 

* 

R 

\ 

i 

^*— 

--TH 

Slotted  Jaw    (Tang  End). 


«*«  4,,-H 


•f* 


Offset  Solid  Jaw  (Tang  End). 


\\ 


Wide  Jaw   (Tang  End). 


Figs.  1122-1133.     Railway  Signal  Association  Standard  Jaws. 


164 


INTERLOCKING. 


Figs.  1134-1145 


R.  S.  A.  SPECIFICATIONS  FOR  GRAY  IRON  CASTINGS. 

1.  Gray  iron  castings  must  be  of  good  sound  iron,  free  from 
flaws,  blow  holes,  flues,  cold  shuts,  or  shrinkage  cracks.     They 
must  conform  to  dimensions  shown  on  drawings  and  must  not 
exceed  the  specified  weight,  when  weight  is  specified. 

2.  Castings     having    any   section     less    than    %    inch    thick 
shall  be  known  as  light  castings. 

Castings  In  which  no  section  is  less  than  two  inches  thick 
shall  be  known  as  heavy  castings. 

Medium  castings  are  those  not  included  in  the  above. 

Light  castings,  sulphur  not  over  0.08  per  cent. ;  medium  cast- 
Ings,  sulphur  not  over  0.10  per  cent.;  heavy  castings,  sulphur 
not  over  0.12  per  cent. 

Transverse  Test.  The  breaking  strength  of  the  arbitration 
bar  under  transverse  load  shall  not  be  under  light  castings,  2500 
IDS.;  medium  castings,  2900  Ibs. ;  heavy  castings,  3300  Ibs. ;  with 
load  applied  at  center  and  points  of  support  12  inches  apart. 


2.  Manufacturers   will    submit,    for   approval,    a   sample   cast- 
ing from  each  pattern,  when  so  requested. 

3.  'When   shown   on   the   blue   print,   each   casting  must    have 
one  or  more  test  lugs.    The  shape,  size  and  number  must  be  as 
specified,   although   the   location   will   be  left   to  the   option   of 
the  manufacturer.     The  test  lugs,  when  broken  off,  shall  show 
tough    and    strong    material. 


R.    S.    A.    SPECIFICATIONS    FOR    MACHINERY    STEEL. 

1.  All  sections  must  be  true  to  size,  free  from  cracks,  flaws 
and  defects  of  all  kinds. 

2.  When  subjected  to  a  tensile  test  the  steel  must  show :  Ten- 
sile strength  per  square  inch  48,000  to  58,000  Ibs.    Elongation 
in  eight  inches,  not  less  than  25  per  cent. 

3.  Phosphorous  not  to  exceed  0.1  per  cent.;  sulphur  not  to 
exceed  0.065   per  cent. 

4.  When  subjected  to  a  bending  test,  either  hot  or  cold,  the 


Figs.  1134-1138.     R.  S.  A.  Standard  Cranks. 

3.  The  manufacturer's  pattern  number  must  appear  on  each 
casting  and  be  so  located  that  it  will  not  wear  off  or  interfere 
with  the  fitting  of  other  parts  to  the  casting. 

4.  Castings  will  be  inspected  at  the  shops  of  the  manufac- 
turer, and  those  which  fail  to  meet  the  above  requirements  will 
be  rejected.     Test  of  test  specimens  may  be  made  at  the  place 
of  manufacture,  the  manufacturer  to  furnish  suitable  apparatus 
to   make  the  test  without  expense  to  the  purchaser ;   or  these 
tests  may  be  made  at  destination,   if  the  purchaser  so  desires, 
In  which  case  the  foundry  will  furnish  two  arbitration  bars  for 
each  melt  used  in  filling  the  shipment. 

A  blue  print  showing  the  arbitration  bar  and  its  mold  will 
be  supplied  to  those  filling  orders  for  gray  iron  castings  for 
the  purchaser,  upon  request. 


Figs.     1139-1145. 


S.    A.    One-Way   Vertical 
Stand. 


Crank 


R.     S.    A.    SPECIFICATIONS    FOR    MALLEABLE     IRON    CASTINGS. 

1.  Malleable  iron  castings  must  be  well  rattled,  clean  and 
reasonably  free  from  flaws  or  shrinkage  cracks.  They  must 
conform  to  the  dimensions  specified  and  must  not  exceed  the 
•peclfied  weight  when  a  weight  is  given. 


steel  must  bend  double  over  a  diameter  equal  to  its  own  thick- 
ness without  showing  any  fracture. 

5.  The  results  of  the  chemical  analysis  made  at  the  steel 
works  of  each  melt  used  to  fill  the  order  must  be  furnished  to 
the  purchaser's  inspector  when  requested. 

Mild  steel  will  be  tested  at  the  shops  where  it  is  to  be  used. 
If  it  fails  to  meet  these  specifications,  it  will  be  rejected  and 
returned  at  the  expense  of  the  manufacturer. 


Figs.  1146-1149 


INTERLOCKING. 


165 


R.    S.    A.    SPECIFICATIONS    FOR    WROUGHT    IRON    BARS. 

1.  All    sections    must    be    true    to    size   and    shape   ordered. 
Round  iron  must  conform  to  the  M.  C.  B.  standard  limit  gauges. 

2.  Iron    must   be   free  from    cracks,    flaws,    unwelded   seams 
and  mechanical  defects  of  all  kinds,  and  must  be  free  from  steel 
scrap. 


The  fractures  must  not  be  more  than  15  per  cent,  crystalline. 

4.  When  subjected  to  bending  test,   either  hot  or  cold,   the 
iron    must   bend    through    an    angle    of   180    degrees    around   a 
diameter  equal  to  twice  the  thickness  of  the  bar  without  crack 
or  fracture.     In   competent   hands   the   iron   must   give   perfect 
welds. 

5.  All  iron  showing  defects  in  working,  rendering  it  unfit  for 
service,  will  be  rejected   and  returned  to   manufacturer   at  his 
expense. 


on- 


— 


One-Way  Crank  Stand  Complete. 


One-Way  Crank  Stand. 


f 
V? 

J£!  1         * 

:>.    ^-^ 
•*r 

~ 

ar- 


•s!«  . 

^^ 


M 


rfi 


*fc= 

"int  <  ! 


J^ 


% 


N<0 


Two-Way  Crank  Stand  Complete. 


V'* 

Two-Way  Crank  Stand. 


i'-A 


Figs.    1146-1149.     Railway   Signal   Association   Standard   Crank    Stands. 


3.     Samples    taken  jp.t    random,    one    test   specimen   from  50             6.     The  iron  shall  be  inspected  at  the  shops  where  it  is  to  b« 

bars,  approximately,  must  pass  the  following  tensile  test :  used   and  if  it  fails  to  meet  the  requirements  of  these  specifi- 

Tensile  strength  per  square  inch,  not  below  48,000  Ibs.  cations,  it  will  be  rejected  and  returned  at  the  expense  of  the 

Elongation  in  eight  inches,  not  less  than  20  per  cent.  manufacturer. 


i66 


INTERLOCKING. 


Figs.  1150-1162 


2-WAY 


Figs.   1150-1153.     Details   of  Multiple  Vertical  Crank  Stands. 
Railway  Signal  Association  Standard. 


Fig.  1157. 


Figs.   1154-1155.     Box  Crank,   Cotters  Above  Frame. 


Fig.  1159. 


Fig.    1 160. 
Figs.   1156-1160.     Separate  Pin  Leadout  Cranks. 


Figs. 


[-ii62.     One  and  Two  Way  Crank  Pins.     R.  S. 
A.   Standard. 


COMPENSATORS. 

The  connection  between  a  lever  and  its  function  being 
equivalent  to  a  solid  iron  rod,  expansion  and  contraction  will 
accompany  change  in  temperature.  Provision  must  be  made 
to  overcome  the  effects  of  such  expansion  and  contraction,  as 
otherwise  on  a  warm  day  the  pipe  line  would  be  too  long 
and  on  a  cold  day  too  short.  This  would  prevent  levers  and 
their  functions  from  making  full  stroke  in  one  direction  or 
the  other.  Serious  variations  in  length  might  take  place 
between  morning  and  noon.  For  this  reason  compensators 
are  used.  A  compensator  reverses  the  direction  of  travel  in 
the  pipe  line  so  that  expansion  or  contraction  in  different 
portions  of  the  line  counteract-  each  other.  Where  there  arc 
no  branch  lines  and  only  one  compensator  is  used,  it  should 
be  placed  midway  between  the  lever  and  its  function.  Should 


Figs.  1163-1166 


INTERLOCKING. 


167 


< -300'- >t<- 300- *<- > 430'- -*<-- 4SO-- > 


A    I2O°  F. 


r 

<400 

i 

II       T    ^°        T 

i 

—  i  

-o    -->k—    o—  —  —  o- 

i                            ; 

!                                           { 

i  o  ..-i—  o  ..   .    , 

B   4O°  F. 


I- 

r 

i 

*  ?            r» 

C  -4O°   F. 

Figs.    1163-1164.     Diagrams  Showing  Effects  of  Temperature  Changes  in  Pipe     Lines.     (See  Table  Below.) 


there  be  branch  lines,  as  when  two  func- 
tions are  operated  from  one  lever,  one 
compensator  should  be  placed  midway  be- 
tween the  end  of  the  shorter  branch  and 
the  lever ;  and  a  second  compensator 
should  be  placed  a  distance  from  the 
end  of  the  longer  branch  equal  to  half 
the  difference  in  length  of  the  two 
branches.  Three  or  more  branches  can 
be  treated  in  a  similar  manner.  If  two 
or  more  compensators  are  to  be  used  and 
there  are  no  branches,  they  should  not  be 
evenly  spaced,  but  each  should  be  in  the 
middle  of  the  section  of  the  pipe  line  to 
be  compensated.  For  instance,  if  two  are 
used,  one  should  be  placed  a  distance  from 
the  lever  equal  to  one-quarter  the  length 
of  the  line,  and  the  second  the  same 
distance  from  the  function.  A  com- 
pensator may  consist  of  a  straight  crank 
(Figs.  1174-1175  and  1185-1204),  or  a 
"lazy-jack"  (Figs.  1163-1164).  The  lat- 
ter consists  of  two  cranks,  one  at  60 


Temp. 
Deg. 
Fahr. 

120 
110 
IOO 

90 

80 
70 
60 

50 
40 
30 
20 

10 

o 

— IO 

—20 

—30 
-40 


Lengths  of  Pipe  Line  in  Feet. 


IOO 
5/8 
ft 

ft 
ft 


A 

A 


if 

54 


200 


it 


A 


ft 

X 

5/8 
it 

i 


250 

1 5/6 
I3/6 
lit 
I 

it 


Mean 
ft 

*/S 

H 

it 
I 
Ift 


300 
lit 
lit 
Ift 
Ift 
it 


350 

2J4 

lit 
lit 


it 


it 
ift 

IT7* 

ii4 
lit 


lit 
lit 

254 


400 

2ft 

254 

lit 


it 

H 
A 

ft 

M 

if 


lit 

2/4 
2ft 


450 
27/& 
2/2 
2ft 
lit 
Ift 
Ift 
3/4 


Ift 
Ift 
lit 
2ft 
2/4 


Note. — The  figures  in  this  table  are  approximately  correct.         The  basis  is  .008"  on  every  100' 

for  1°   F.  variation  in  temperature. 


Fig.   1165.     Pipe  Compensator.    R.  S.  A.  Standard. 


Fig.    1166.     Parallel    Compei.sator.      Great 
Western  Railway  of  England. 


1 68 


INTERLOCKING. 


Figs.  1167-1175 


Fig.    1167.     One   Way    Compensator    Base. 
R.  S.  A.  Standard. 

Names    of    Parts,    Vertical    Lazy   Jack    Compen 
sators;  Figs.  1168-1171. 

A'  One-Way  Vertical  Lazy  Jack  Compensator 

B  Two-Way  Vertical  Lazy  Jack  Compensator 

1  One-Way  Stand 

2  Two-Way  Stand 

3  n"  x  n"  Obtuse  Angle  Crank 

4  u"  x  n"  Acute  Angle  Crank 

5  Connecting  Link 

8  Center  Pin  for  4  n     Spacing  Washer 

9  Center  Pin  for  B  12     Cotter 
10    Jaiv  Pin  13     Cotter 


Figs.    1168-1171.     Vertical    Lazy    Jack    Pipe    Com- 
pensator. 

deg.,  the  other  at  120  deg.,  mounted  on  a  base  and  connected  by 
a  short  link.  By  using  this  device  the  pipe  can  be  continued 
in  a  straight  line  while  the  direction  of  its  motion  is  reversed. 
Sometimes  it  is  possible  to  compensate  a  pipe  line  by  using 
one  or  more  cranks,  so  arranged  as  to  reverse  the  motion. 


Figs.  1172-1173.     Adjustable  Crank.     Great  Western 
of  England. 


Figs.    1174-1175.     Straight    Arm    Compensator.      Great 
Western   of  England. 


Figs.  1176-1184 


INTERLOCKING. 


169 


It  is  customary  in  connecting  up  pipe  lines  to  set  all  appa- 
ratus "on  center"  so  that  the  throw  may  be  equal  in  each 
direction,  but  to  provide  proper  compensation  and  take  care 
of  all  temperature  effects  the  table  shown  in  connection  with 


The  stand,  which  with  one  bar  forms  a  complete  unit,  can 
be  assembled  in  groups  of  as  many  "ways"  as  may  be  required, 
always  maintaining  the  proper  centers  of  the  pipe  line  with 
whatever  degree  bar  is  used.  The  stands  are  designed  with 


|<_  --B 4: C 

Fig.    1176.     Self-Compensating    Pipe   Run   for    Pipe   Connected    Crossover.      Michigan  Central. 


figs.  1163-1164  should  be  used,  cutting  the  pipe  long  when 
the  temperature  is  above  the  mean  and  short  when  below.  In 
this  way  the  throw  will  be  equalized.  Otherwise  the  throw 
of  the  cranks  will  be  further  on  one  side  of  center  in  warm 
weather  than  on  the  other  side  in  cold  weather.  Figs.  1162- 
1164  show  diagrammatically  the  effects  of  temperature  on 
pipe  lines.  The  coefficient  of  expansion  of  iron,  .008  in.  per 
100  ft.  one  deg.  F.,  is  used  as  the  basis  of  the  table  and 
diagram.  If  the  mean  temperature  of  the  locality  in  whicb 


Figs.   1177-1178.     Straight  Arm  Crank.     R.  S.   A. 
Standard. 

the    plant    is    situated    Is    other    than    40    deg.,    it    should    be 
ascertained   and    the   table    corrected    accordingly. 

Cranks  and  compensators  are  mounted  on  stands  or  founda- 
tions made  of  iron  legs  with  wooden  tops  and  bottoms  or  of 
concrete  (Figs.  1261-1267  and  1242-1245),  similar  to  those  used 
for  pipe  carriers. 


DEFLECTING    BARS. 

Figs.    1179-1180    illustrate    the    Federal    bori/.ontal    deflecting 
bar  for  making  a  right  angle  turn. 

Figs.     1181-1184    Illustrate    the    G.    R.    S.    adjustable    deflect- 


Figs.    1179-1180.     Federal   Horizontal    Deflecting  Bar. 

Ing  bar  stand  with  deflecting  bars  varying  from  221/-!'  to  90  deg. 
The  stands  can  be  Installed  wherever  It  is  practicable  to  use 
a  curved  bnr  for  making  an  angle  or  turn  in  the  pipe  lines,  with- 
out changing  the  center  line  of  the  pipe  run ;  and  the  stand  can 
be  used  with  any  of  the  cranks  which  are  shown  in  Fig.  1181. 


Figs.  1181-1184.     Deflecting  Bars,  General  Railway  Sig- 
nal  Company. 

parallel  bearing  surfaces  to  facilitate  the  spacing  of  adjacent 
stands.  Fig.  1182  illustrates  the  assembly  of  two  bars  set 
parallel  to  each  other,  making  a  turn  of  22%  deg.  in  the 
pipe  line.  Fig.  1183  shows  a  similar  assembly,  but  with  bars 
for  making  a  90-deg.  angle.  Fig.  1184  illustrates  the  assembly 


170 


INTERLOCKING. 


Figs.  1185-1204 


of  two  bars  spaced  for  leading  from  lever  to  pipe  line  (i.  e., 
from  five  in.  to  2%  in.  centers),  as  required  at  all  interlocking 
tower  leadouts. 


In  cases  of  necessity,  if  the  proper  degree  bar  is  not  obtain 
able  a  90-deg.  bar,  for  instance,  may  be  flattened  to  the 
curvature  of  a  22V,  deg.  bar. 


33     5      29  33  22 


33     4     29  33  22  I  22 

oMo 


Figs.    1185-1204.     Deflecting   Bars   and   Radial  Arms. 


Names  of  Parts  of  Deflecting  Bars  and  Radial  Arms;  Figs.  1185-1204. 


A     Vertical  Deflecting  Bar  2 

B     Group  of  Three  Vertical  Defied-  3 

ing  Bars 

C    Horizontal  Deflecting  Bar  4 

D     Group   of  Three  Horizontal  De-  5 

fleeting  Bars 

E    Short  Horizontal  Deflecting  Bar  6 

F     Group   of   Three  Short  Horizon-  7 

tal  Deflecting  Bars  8 

G    Deflecting  Stand,   Two   Way  9 
H     Deflecting  Stand,  Three  Way 

J      Radial  Arm  and  Stand,  One  Way  10 

K    Radial  Arm  and  Stand,  Two  Way  n 

M     Radial   Arm    and    Stand,    Three  12 

Way  13 

N     Wrought  Jaiv  for  G  and  H  14 

i     Vertical    Deflecting    Bar    Frame  15 


Horizontal  Deflecting  Bar  Frame  16 

Short  Horizontal  Deflecting  Bar  17 

Frame  18 

Deflecting  Stand  Base,  Two  Way  19 

Deflecting  Stand  Base,  Three  20 

Way  22 

Radial  Arm  Stand,  One  Way  25 

Radial  Arm  Stand,  Tzvo  Way  26 

Radial  Arm  Stand,  Three  Way  27 

Cover  for  Short  Deflecting  Bar  28 

Frame  29 

Cover  for  G  3° 

Cover  for  H  31 

Cap  for  2  32 

Roller  33 

Washer  34 

Short  Radial  Rod  35 


Long  Radial  Rod 

Link 

9"  Radial  Arm 

n->4"  Radial  Arm 

14^2"  Radial  Arm 

Bolt 

Pin 

Center  Pin  for  M 

Center  Pin  for  K 

Center  Pin  for  J 

Jaw  Pin  for  N 

Roller  Pin 

Cotter 

Cotter 

Cotter 

Spring  Washer 

Spacing  Washer 


Figs.  1205-1241 


INTERLOCKING. 


171 


PIPE   AND    WIRE    CARRIERS    AND   FOUNDATIONS. 

Pipe  is  guided  and  supported  by  pipe  carriers  (Figs.  1205 
1233  and  1254-1259).  They  consist  of  an  iron  frame  carry- 
ing wheels  or  rollers  between  which  the  pipe  moves.  Those 
in  which  the  hub  of  the  wheel  travels  in  a  slot  are  known 
as  anti-friction  pipe  carriers  (Pigs.  1254-1256  and  C,  B,  F, 
H,  N  and  P,  Figs.  1205-1233)  ;  sometimes  the  roller  also  Is 
made  anti-friction.  These  pipe  carriers  are  fastened  by  lag 
screws  to  long  ties  or  to  foundations.  They  may  be  made 
in  units  to  be  mounted  side  by  side  or  in  groups  of  any  re- 


quired number.  The  foundations  may  consist  of  concrete  to 
which  a  block  of  wood  is  attached  (Figs.  1242-1247),  or  of 
iron  legs  bolted  to  two  wooden  blocks.  They  are  set  In  the 
ground  a  sufficient  distance  from  the  nearest  rail  to  provide 
clearance  for  the  carriers  (Fig.  1241).  Carriers  are  usually 
spaced  not  more  than  seven  ft.  apart  as  the  pipe  is  under  strain 
both  In  tension  and  compression.  Where  pipe  lines  cross 
the  track,  transverse  or  hanging  pipe  carriers  are  used  (G,  K, 
and  L.  Figs.  1215-1219,  and  Figs.  1242-1254),  these  being 
secured  to  the  ties  with  lag  screws. 


Jl_JLJLJ_JLJLJLJLJir 


Figs.    1205-1233.     Pipe    Carriers. 


l-WAY 

Figs.   1234-1239.   Universal 
Pipe       Line       Carrier 
Base.  W.  K.  Ken- 
ly  Company. 


This  dimension  to  be  increased  £% 
-  -  -  for  each  additional  run  of  pipe. 


— -4'3-y.— > 

~r&g— i±r.i~- 


Rto 

fel 


^^ 


Fig.    1240.     Rail    Pipe    Support.      Michigan    Central. 


Fig.    1241.     Standard    Clearance  for   Pipe   Lines. 
New  York  Central  &  Hudson  River. 


172 


INTERLOCKING. 


Figs.  1242-1256 


ONE-WAY,  COMPLETE . 


TWO-WAY,  COMPLETE . 


UNIVERSAL    PIPE    LINE    CARRIER   BASE. 

This  device  is  made  of  malleable  iron  and  was  designed  as 
an  Improvement  over  the  old  wooden  base  which  has  been 
in  use  for  so  many  years.  The  use  of  this  base  effects  a  con- 
siderable saving  in  labor,  both  during  and  after  the  time  of  in- 
stallation of  a  plant,  on  account  of  the  fact  that  no  renewal  Is 
necessary  every  six  or  eight  years,  as  is  the  case  when  wooden 
bases  are  used. 

Mechanically,  the  malleable  base  does  away  with  lag  screws 
and  affords  an  easier  lever  manipulation,  on  account  of  the 
increased  rigidity  of  the  malleable  construction  over  wood. 
A  lateral  adjustment  can  be  made  after  installation  of  the  base 
on  the  concrete  block,  and  a  second  adjustment  of  the  pipe 
carrier  if  necessary.  The  difference  in  price  between  the  malle- 
able and  wooden  tops  is  slight. 

The  base  is  designed  to  mount  the  universal  pipe  carrier  now 
ill  common  use.  Two  patterns  are  furnished,  for  the  carrier 
bored  for  %  inch  or  %  inch.  Bases  are  furnished  in  six  sizes, 
viz.  :  One,  two,  three,  four,  six  and  eight  way ;  with  six  and 
eight  way  bases  lap-jointed  to  provide  for  large  plants.  The 
various  forms  of  base  are  shown  in  Figs.  1234-1239,  the  six 
and  eight  way  bases  having  lap  joints  which  prevent  lateral 
or  vertical  displacement  of  the  bases  on  a  wide  pipe  run. 

The  Universal  Pipe  Lino  Carrier  Base  is  made  by  the  \V.  K. 
Kenly  Co. 


Figs.   1242-1243.     R.   S.  A.  Transverse   Pipe  Carriers. 


Names   of   Parts;    Figs.    1205-1233. 

A  One  Way  Plain  Pipe  Carrier 

B  Two  Way  Plain  Pipe  Carrier 

C  One  Way  "Universal"  Pipe  Carrier 

D  One  Way  Anti-Friction  Pipe  Carrier 

E  Two  Way  Anti-Friction  Pipe  Carrier 

F  One  Way  "Universal"  Pipe  Carrier 

G  Transverse  Pipe  Carrier,  One  Way 

H  Special  One  Way  Anti-Friction  Pipe 

Carrier  for  Fastening  to   Ties 

K  Two  Way  Transverse  Pipe  Carrier 

L  One  Way  Transverse  Pipe  Carrier 

M  Adjustable  Pipe  Guide 


<* 


-o 


TWO-WAY   HANGER. 


SUPPORT. 


r*  — 

81                                       A          /$\ 

-|>LL.                               J| 
32                           .  .                       116 

"    ' 

^_ 

—  THREE  -WAY.  =  10  "  

PINS.(C.R.STEEL.) 

FOR  DETAILS  or  SHEAVE  AND  COTTER  PIN  SeE  No.  1071. 
FOR  ASSEMBLY  DRAWING  SEE  No.  1072. 


Figs.    1251-1254.     Details  of   R.    S.    A.   Transverse    Pipe 
Carriers. 


N     One  Way  Rail  Clip  Transverse 

Pipe  Carrier 

P    Rail  Clip  Pipe  Carrier 
Q     Strap  Pipe  Carrier 
R    Strap  Pipe  Carrier 


STAND .  (COM L  STEEL)  SHEAVE . 

7,.  (IRON  CASTING) 

2D 


ASSEMBLY. 

Figs.  1244-1250.     Details  of  R.  S.  A.  Strap  Pipe  Carrier. 


Figs.  1255-1256.      Double  and  Single  Deck  Anti-Fric- 
tion Pipe  Carriers.  T.  George  Stiles  Company. 


Figs.  1257-1269 


INTERLOCKING. 


173 


2x8  Oak 


Figs.  1257-1258.     "Universal"  Anti- 
Friction      Pipe      Carriers.       T. 
George  Stiles   Company. 


One  and  Two 
Crank, 

Figs.  1259-1260 


Four -way  Box  Crank, 


K 


Figs.     1261-1262. 


r 


>.     k 


j<-  -  -       -  -  -38%'  9  fo  12  Way  ----  ->| 


Figs.    1265-1266.      Standard    Pipe    Carrier    Founda- 
tion, with   Concrete  Base.     New  York. 


PJpe  Ccrrr/er. 

Figs.  1263-1264, 

Figs.    1263-1264.     Concrete   Foundations. 
Michigan    Central. 


Figs.    1267.     Pipe   and   Wire   Carriers  and   Concrete 

Foundations.      The    Buffalo    Railway 

Supply    Company. 


Fig.  1268.     Iron  Base  for  Pipe  and  Wire  Carriers.     Union  Switch  and 

Signal  Company. 


"C. 


\4 


n» 


n°2 


&-- 


Fig.    1269.     R.    S.   A.    Standard   Pipe 
Carrier    Concrete    Foundation. 


INTERLOCKING. 


Figs.  1270-1292 


Figs.    1270-1271.     Compensator    Foundation;    Iron    Piers 
Set  in  Concrete. 


„ 8- ->i  H— <- M 

Figs.     1272-1273.       Cast-Iron     Pier 
for  Concrete  Foundation. 


Figs.  1274-1276.     Crank  and  Chain  Wheel  Foundations;  Iron  Piers  Set 

in  Concrete. 


Figs.  1277-1278.     Pipe  Carrier  Foundations;  Wooden  Tops,  Bolted  to  Iron 
Piers,   Set   in   Concrete. 


Fig.  1282.     Journal  for 

Square    Rocker 

Shafts. 


Figs.    1279-1281.     Arms 


for   Square   Kc 
Shafts. 

Q               C 

)cker                     = 
1 

B 

l  i  !         !  I          :  j                 ] 

ii       i  i  i 

CD                t 

j 

T  ^ 

Figs.    1283-1285.     Rocker    Shaft 

Bearings  for  Square  Rocker 

Shafts. 


O         £1 


If 


Figs.   1286-1289.     Rocker   Shaft  Bearings   for   Use    Between   Ties. 


Figs.   "1290-1292.      Rocker    Shaft 
Stands. 


Figs.  1293-1337 


INTERLOCKING. 


WIRE    CONNECTIONS    AND    COMPENSATION. 

Wire  is  supported  and  guided  by  wire  carriers  (Figs.  1309- 
1333),  mounted  on  stakes  (Figs.  1336-1337  and  1334-1336), 
or  on  pipe  carrier  foundations.  Where  the  direction  of  the 
line  Is  changed,  one  quarter  In.  proof  chain  is  introduced  Into 


F:::::^:±:EE!E3 


S.Safr'tt 
Stee/Syna/Wir*. 


IS) 


Figs.     1305-1306.       Splice     and     Method     of     Attaching 
Wire   Eye  to  Wire.     New  York  Central. 


Adjustable 
Connector, 

with 
Shackle. 


Adjustable 
Connector. 


Figs.    1307-1308.     Wire   Adjusting    Screws. 


Shackle.  Hook  Split  Link.          Double 

Shackle.  Shackle. 

Figs.   1293-1304. 


31 

IC~~5 

FiF  ] 

5:: 

:  ;§)  ^^ 

11 

sj= 

i  ;§)     ^ 

=  .  :  1 

5 

i 

© 

Figs.  1309-1333.    Wire  Carriers. 


k-  -£>4-'-  ----------------  f  -------  -*'—  .......  - 


Figs.     1336-1337.      Wooden 

Figs.  1334-1335.      Two-Way    Adjustable    Wire    Carrier    and    Cast-Iron    Stake.      Buffalo  Stake   for  Wire 

Railway  Supply  Company.  Carriers. 


176 


INTERLOCKING. 


Figs.  1338-1370 


LU!— J 


Fig.   1348. 


Fig.  1349. 


Figs.  1348-1349.     Gain  Stroke 
Chain  Wheels. 


Figs.  1338-1347.     One,  Two  and  Three  Way  Horizontal  Chain  Wheels. 


3  .!  C  J 


i  C      ) U L 


Figs.   1350-1359.     Types  of  Tandem  Horizontal  Chain  Wheels. 


Figs.  1360-1367.     Multiple  Horizontal 
Chain  Wheels. 


i- RU- J 


) L 


i-2  W  E 6 1/4- 

Figs.  1368-1370.     Types  of  Vertical  Chain  Wheels. 


fiii  ii;j 

U A  \/<i — 4 


Figs.  1371-1386 


INTERLOCKING. 


177 


the  line  and  led  around  chain  wheels  (Figs.  1339-1398).     These  of   connecting    direct    to   balance    lever    5,    so    that    should    the 

are  mounted  on  foundations  like  cranks.     The  chain  is  fastened  back    wire    break,    the    right-hand    end    of    lever    8    will    rise 

ro  the  wire  by  wire  eyes  and  split  links  (Figs.   1293-1304).  through    link    7    until     the    lever    assumes    a    nearly    vertical 

A    wire    compensator    is    shown    in   Figs.    1409-1410.      Weight  position,    when    it    will    allow    the   pulling    wire    to    slip    off    of 


-ia a 


J2HX Eli ECi F3Ps EjC^ rax        rarv         rar 


ffi 


T\^         nrv    ___FfV-       FT^ —    j^         ^ 

^I  1^  CT<  ?   ; !   <  1 1 


Figs.   1371-1386.     Types  of  Box  Wheels. 

14  at  end  of  lever  13,  which  carries  chain  wheels,  takes  up  the  hook  at  its  left-hand  end,  permitting  lever  13  with  its 
all  slack  in  wires  and  keeps  them  taut.  The  weight  of  14  is  weight  to  drop  harmlessly  instead  of  pulling  the  signal  clear, 
able  to  overcome  that  .of  the  spectacle  and  counterweight  6  Figs.  1411-1412  illustrate  a  method  by  which  a  single  wire 
when  signal  is  clear.  Wires  are  hooked  to  the  ends  of  dis-  signal  may  be  adjusted  by  the  signalman  to  changes  in  tern- 
engaging  lever  8  which  rests  in  link  7.  This  is  done  instead  perature. 


I78 


INTERLOCKING. 


Figs.  1387-1410 


Figs.     1387-1390.     Roller    Bearing    Horizontal 
Chain   Wheels. 


L 


T" 

CO 

L 


T 

"oo 


t* 


<n 

1 


Figs.    1391-1398.     Types   of  Vertical   Chain  Wheels. 


Figs.  1399-1408.     Types  of  Single  Vertical  Chain  Wheels. 


Names  of  Parts  of  Wire  Compensator;  Figs.  1409-1410. 


1  Balance  Lever  Bracket 

2  Half-Clamp 

3  Pin 

4  Bolt 

5  Balance  Lever 

6  Counterweight 

8  Disengaging  Lever 

9  Chain   Wheels 

10  SYoV  Bracket 

11  Chain   Wheel  Pin 

12  Bolts 

13  Compensator  Lever 


13 


14  Compensator  Counterweight 

15  Compensator  Lever  Bracket 

1 6  Ptw 

17  £o/f 

18  Fronf  Ho//  of  C7a»»/> 

19  .Sacfc  Ho//  of  Clamp 

20  Clamp  Bolt 


Figs.    1409-1410.     Wire    Compensator. 


Figs.  1411-1419 


INTERLOCKING. 


179 


?,  Sx/Z  create  carr/edo/? 
7Jr/4"upr/a/?fe  a f each 
end  m'tf  2,2"p/pe  c/p- 
rig  fits  SrO"aparf 


Alternative  Method  of 
Attaching  He/p  We/ghf 
Levers. 


Figs.    1411-1412.     Single     Wire     Compensator     and   Leadout   Arrangements. 


Names  of  Parts,  Special  Lugs  and  Attachments, 
for  Changing  from  Pipe  to  Wire;  Figs.  1413-1419. 


A 
B 
C 

i 

2 

3 


With  Tang  End  Rod 

With  Jaw 

With  /azt'  and  Tang  End;  One  Wire 

Lug  with  Tang  End  and  Eye 

Lug  with  Jaw  and  Eye 

Lug  with  Tang  End  and  Jaw 


4  One-Way  Special  Wheel 

5  Pipe  Carrier 

6  Chain 

7  Wire  Eye 

8  Split  Link 

9  Shackle 


Figs.    1413-1419.     Special    Lugs,    Attachments    and    Wheels    for    Changing    from    Pipe    to    Wire    Connections. 


i8o 


INTERLOCKING. 


Figs.  1420-1444 


OIL    PIPES. 

Where  it  is  necessary  to  run  pipe  lines  under  ground,  as 
through  a  street,  it  is  customary  to  enclose  the  one  inch  pipe 
in  two  inch  or  two  and  one-half  inch  galvanized  pipe  filled  with 
oil.  Stuffing  boxes  and  plungers  are  provided  at  the  ends  to 
prevent  the  oil  from  escaping ,  and  cranks  are  mounted  in  oil 
boxes.  The  weight  of  the  earth  on  the  large  pipe  is  usually 
sufficient  to  hold  it  in  line,  no  foundations  being  necessary 
(Figs.  1425-1444).  When  it  is  desired  to  run  wires  under 
ground  galvanized  pipe  is  used  and  stuffing  boxes  (Figs.  1420- 
1424)  are  provided. 


Fig.   1421.     Wire  Pack- 
ing   Box.     Bryant 
Zinc  Company. 


Figs.   1422-1423.     Single  and   Double   Wire   Stuffing 
Boxes.      Railroad    Supply  Company. 


Fig.     1420.     Single    Wire    Stuffing    Box.     Brya 
Company. 


Fig.    1424.     Packing   Box   and    Oil   Inlet.      Bryant   Zinc   Company. 


Figs.    1425-1444.     Oil    Crank    Boxes,    Oil    Pipe,    Stuffing    Boxes    and    Plungers. 


Figs.  1445-1456 


INTERLOCKING. 


181 


SWITCH    OPERATING    AND    LOCKING    MECHANISMS. 

Next  to  the  Interlocking  machine  itself  the  most  important 
part  of  an  interlocking  plant  is  the  mechanism  by  which  the 
switches  are  operated.  The  simplest  arrangement  that  could  be 
used  would  be  a  direct  connection  from  the  lever  to  the  head 
rod  of  the  switch.  This  would  throw  the  switch,  but,  as  there 
is  considerable  spring  in  the  connection,  it  would  give  no  as- 
surance that  the  switch  had  entirely  completed  its  movement. 
For  this  reason  some  form  of  locking  is  necessary.  This  is 


accomplished  in  two  ways  ;  by  facing  point  locks  and  by  switch 
and  lock  movements. 

A  facing  point  lock  (Figs.  1459-1479)  consists  of  a  plunger 
casting,  a  plunger  and  a  lock  rod.  The  lock  rod  is  attached 
to  the  movable  part  of  the  switch  and  passes  through  a  slot 
in  the  plunger  casting.  The  plunger  is  operated  by  a  separate 
lever  (interlocked  with  the  switch  lever)  and  moves  through 
the  plunger  casting  at  right  angles  to  the  lock  rod.  When  the 


876 


11  7  e.*-  gl 

gs.    1445-1446.     Switch    and    Lock    Movement    for    Switch. 

Names  of  Parts  of  Switch  and  Lock  Movement; 


Figs.  1445-1446. 


i 

2 

3 
4 
5 
6 

7 
8 

9 
10 


Base  12 

i"  x  5"  Stud  13 
Cap  for  Guide  Rollers         14 

y^"  x  1 54"  Cotter  15 

i"  x  4"  Stud  1 6 

Washer  17 

i54"  x  5"  Stud  1 8 

Washer  19 

Cotter  20 

Guide  Roller  21 

Guide  Roller  22 


Upper  Slide  Bar 
Lower  Slide  Bar 
Lug  for  Slide  Bat- 
Lug  for  Slide  Bar 
Rivet 
Rivet 

Y2"  x  4^4"  Bolt 
Bolt 

Escapement  Crank 
Operating  Roller 
i"  x  3"  Stud 


Figs.  1447-1448.     Johnson  Type  Switch  and 
Lock    Movement. 


Names  of  Parts  for  Johnson  Type  Switch 
and  Lock  Movement;  Figs.  1447-1448. 

1  Base 

2  Pin 

3  Cotter 

4  Escapement  Crank 

5  Crank 

6  Pin 

7  Operating  Roller 

8  Cotter 

g    Special  T  Crank 


5  10  20     21 

gs.    1449-1450.     Switch  and    Lock    Movement   for   Derails, 
Locking  One   Way  Only. 

Names  of  Parts  of  Derail  Switch  and  Lock  Movement; 
Figs.  1449-1450. 


ROLLER . 


STAND  .  (IRON   CASTMC) 


1  Base 

2  Stud 

3  Cap  for  Guide  Rollers 

4  Cotter 

5  Stud 

6  Washer 

7  Pin 

8  Cotter 

9  Guide  Roller 

10  Guide  Roller 

11  Upper  Slide  Bar 


12  Lower  Slide   Bar 

13  Slide  Bar  Lug 

14  Slide  Bar  Lug 

15  1A"  x  3"  Rirct 

1 6  C.  S.  H.  Bolt 

17  Locking  Plunger 

18  y2"  x  4^"  Bolt 

19  Slide  Bar  Stop 

20  54"  x  3"  Pin 

21  Operating  Roller 

22  Escapement  Crank 


7>--v/8l*'u 

f  Ti                                  ^2l 

,  W  2                               V"? 

1  ' 

-^^                                      ..-• 

®l 

PLUNGER      -^=-0:::—  -;-.-< 

(C.R.STEEL)                                                           j^- 

=  1? 

§ 

..  _, 


ASSEMBLY. 


PIN  .(CR.STEEL) 


Figs.   1451-1456. 


PLUNGER  LOCK. 

R.  S.  A.   Standard   Plunger  Lock. 


182 


INTERLOCKING. 


Figs.  1457-1466 


switch  is  either  fully  normal  or  fully  reversed,  one  or  the 
other  of  two  holes  drilled  in  the  lock  rod  is  in  line  with 
the  hole  in  the  plunger  casting  through  which  the  plunger 
moves,  and  when  the  lever  which  operates  the  plunger  (known 
as  the  lock  lever)  is  reversed,  the  plunger  passes  through  the 
lock  rod,  thereby  holding  the  switch  firmly  in  place.  Facing 
point  locks  are  applied  in  two  ways,  known  as  inside  connected 
(Figs.  1473-1474)  and  outside  connected  (Figs.  1475-1478  and 
1479).  In  the  former,  the  plunger  casting  is  mounted  on  the 
head  block  between  the  rails  and  the  head  or  bridle  rod  is 
used  as  lock  rod.  In  the  latter  the  plunger  casting  is  mounted 
outside  the  rails  and  a  separate  rod  (see  Figs.  1526-1527  and 


13  16 

Figs.  1457-1458.     Switch  and  Lock  Movement  Using 
Notched   Lock  Rod. 


10 


o- 


"A 


i^.1 


T 

<M- 

0 

c    , 

i 
i 

4 

5 

i 
1  — 

^D 

J 

! 

™ 

LI 

i 
i 

1 

Q 

0- 

U-  4X— I 


in  the  lock  rod,  and  a  lug  for  driving  the  escapement  crank, 
which  actuates  the  throw  rod  and  moves  the  switch.  Normally 
one  lug  or  plunger  is  engaged  with  the  lock  rod,  holding  the 
switch  locked.  When  the  operating  rod  is  moved  the  first 
portion  of  its  stroke  withdraws  the  plunger  or  lug  and  un- 
locks the  switch,  the  second  portion  actuates  the  escapement 
crank  and  throws  the  switch  and  the  last  portion  inserts  the 
other  plunger  or  lug  locking  the  switch.  These  plungers  or 
lugs  may  be  of  different  shapes  or  placed  in  such  relation 
to  each  other  that  they  cannot  both  enter  the  same  notch  or 
hole  in  the  lock  rod.  Thus,  should  the  throw  rod  become 
disconnected,  the  switch  could  not  be  falsely  locked.  For  use 

Names  of  Parts  of  Switch  and  Lock 
Movement;   Figs.    1457-1458 

1  Base 

2  Stud 

3  Cap  for  Guide  Rollers 

4  Cotier 

5  Yoke  for  Guide  Rollers  and  Lock 

Rod 

6  Stud 

7  Guide  Roller 

8  Center  Guide  Roller 

9  Upper  Slide  Bar 

10  Lover  Slide  Bar 

11  Lug  for  Slide  Bar 

12  Rivet 

13  Rivet 

14  Upper  Locking  Dog 

15  Lozver   Locking   Dog 

1 6  Pin 

17  Operating  Roller 

18  Pin 

19  Cap  for  Crank  and  Center  Roller 

20  Escapement  Crank 

Names  of  Parts  of  Plunger  Locks; 
Figs.  1459-1466. 

Single  Plunger  Lock 

Double     Plunger     Lock     Roller 

Bearing 

Single  Plunger  Lock,  Roller  Bear- 
ing, Wide  Base 

Left  Hand  Single  Plunger  Lock. 
Roller  Bearing 

Plunger  Casting  for  A 

Plunger  Casting  for  B 

Plunger  fasting  for  C 

Plunger  Casting  for  D 

Plunger  for  D 

Plunger  for  C 

Plunger  for  A  and  B 

Roller  Pin  for  D 

Roller  Pin  for  B 

Roller  Pin  for  C 

Roller  for  B 

Roller  for  C 

Roller  for  D 

Cotter 


Figs.  1459-1466.  Plunger  Locks. 


1534-1542)  is  attached  to  the  head  rod,  or  may  be  made  part 
of  it.  Outside  connected  facing  point  locks  are  more  extensively 
used  because  they  are  not  liable  to  injury  from  dragging  brake 
rigging,  etc. 

The  use  of  facing  point  locks  necessitates  an  additional  lever 
In  the  machine  and  a  separate  line  of  connections.  To  save 
the  cost  of  these,  switch  and  lock  movements  (Figs.  1445-1452) 
are  sometimes  employed.  A  switch  and  lock  movement  con- 
sists essentially  of  a  frame  on  which  are  mounted  an  operat- 
ing bar,  escapement  crank,  and  guides  for  the  operating  bar 
and  lock  rod.  To  the  operating  bar  are  attached  lugs  or 
plungers  for  locking  the  switch  by  entering  holes  or  notches 


at  derails,  where  it  is  necessary  to  lock  only  one  way, 
special  form  of  switch  and  lock  movement  may  be  used  (Figs. 
1449-1450).  Another  form  of  movement  (Figs.  1447-1448)  re- 
quires a  separate  plunger  casting,  having  two  plungers  enter- 
ing from  opposite  ends  (Figs.  1461-1462),  known  as  a  duplex- 
lock,  connected  directly  to  the  pipe  line.  A  switch  layout  with •• 
switch  and  lock  movement  may  be  seen  in  Figs.  1480-1481.  Thee 
weak  point  of  the  switch  and  lock  movement  is  the  small- 
amount  of  motion  available  for  locking  the  switch.  Conse-: 
quently,  owing  to  the  spring  and  lost  motion  in  the  connections,,-, 
a  lever  might  be  fully  reversed  without  causing  the  move- 
ment to  complete  its  stroke.  Also  the  one  pipe  line  becoming* 


Figs.  1467-1479 


INTERLOCKING. 


183 


rdF 

1 

A 

~\ 

P 

O     G^ 

A 

-i] 

0     0- 

Y      \< 

O 


Names  of  Parts  of  Plunger  Locks; 
Figs.  1467-1478. 

A    Single  Plunger  Locking  Stand 
B    Double    Plunger    Locking   Stand 

for  Adjustable  Lock  Rod 
C    Left  Hand  Single  Plunger  Lock- 
ing Slide 
Single    Plunger   Locking    Stand, 

Wide  Base,  Roller  Bearing 
Double   Plunger  Locking   Stand, 
Wide   Base,   for   Adjustable 
Lock  Rod,  Roller  Bearing 
Duplex  Facing  Point  Lock 


I 

2 

3 
4 
5 
6 

7 
8 

9 
10 

ii 

12 
13 
14 
15 


Plunger  Casting  for  A 

Plunger  Casting  for  B 

Plunger  Casting  for  C 

Plunger  Casting  for  D 

Plunger    Casting    for    E 

Plunger  Casting  for  F 

Plunger 

Right  Hand  Plunger  for  F 

Left  Hand  Plunger  for  F 

Yoke  Rod 

Roller  Pin 

Roller  Pin 

Roller  for  D 

Roller  for  E 

Cotter 


p2 

&- 

cK 

, 

£ 

5 

fi 

11 

^  —  Is* 

in 

< 

6 

~> 

—  }  s 

Figs.  1467-1478.     Plunger  Locks. 


Fig.  1479.     Inside    Connected    Facing    Point    Lock  and  Switch  Fittings.     Detector  Bar  Ahead  of  Points. 


184 


INTERLOCKING. 


Figs.  1480-1482 


Fig.  1480.     Inside  Connected  Facing  Point  Lock,  Throw  Rod   and   Inside    Parallel    Bar    (Detector   Bar).     Great 

Western   Railway   of   England. 


e 


Fig.  1481.    Outside    Connected  Facing  Point  Lock  and  Switch  Connections,  with  Bolt  Lock.    Two  Detector 

Bars  Behind  the  Points. 


M     Ifffl 


Fig.   1482.     Outside    Connected  Facing  Point  Lock  and    Switch    Fittings,    with    Bolt    Lock.      Detector    Bar 

Ahead   of  the  Points. 


Figs.  1483-1485 


INTERLOCKING. 


185 


D-a-D-H-  n 

I      i  a  i  i r~--~t^ 


uuuu 


Fig.  1483.     Outside   Connected    Facing   Point   Lock  and    Switch    Fittings,    with   Bolt   Lock.     Two   De- 
tector Bars  Behind  Points,  Moved  by  a  Rocker  Shaft. 


in 


nn 


Fig.    1484.     Switch    and    Lock    Movement,    Switch    Fittings    and    Bolt    Lock.     Detector    Bar    Ahead    of    Points. 


Fig.  1485.     Method    of  Plating  and  Tying  Double  Slip    Switch,    with    Movable    Point    Frogs.      Detector    Bars 
Not    Shown;    Tie    Plates    Insulated.     Long   Island    Railroad. 


i86 


INTERLOCKING. 


Figs.  1486-1512 


Left. 


RigJit. 


o        o 


O 


Left. 


Left. 


Right. 

> 


O  O 


Left. 


Right. 


O 


Left. 


Left. 


O 


O 0 


r  \ 

.0    O. 


Left. 


Right. 


O  O 


Left. 


O  O 


Right. 


Left. 


I  I 


O 


o 


Figs.   1486-1512.     Switch   Point  Lugs. 


Right. 


Right.         (— i 


Right. 


Right. 


o 


Figs.  1513-1530 


INTERLOCKING. 


187 


Figs.   1513-1521.     Throw  Rods  and  Switch   Adjustments. 


^"i;     -^  — 

X5                                      X3 

™ 

[—  i  —            ^~ 

^r—  ^™             ,_^,       --^,                                x 

"\V 

^                                                          M:ii'l±J          tt 

Figs.  1522-1527.     Adjustable  Lock  Rods. 

Names  of  Parts  of  Adjustable  Lock  Rods;  Figs. 
1522-1527. 

A    Adjustable  Lock  Rod  for  Switch  and  Lock  Move- 
ment.    Figs.  1457-1458. 
B      Adjustable  Lock  Rod  for  Facing  Point  Lock 

1  Lock  Rod 

2  Adjusting  Lock  Plate,  Right  Hand 
za  Adjusting  Lock  Plate,  Left  Hand 

3  y^"  x  2^4"  Bolt  and  Nut 

4  24"  Washer  8     iJ4"  Screw  Jaw 

5  Adjusting  Sleeve        9     J/6"  x  2f6"  Pin  and  Cotter 

6  Jam  Nut  10    Lock  Rod 

7  Jam  Nut  n     Adjustable  Locking  Plate 


1528.     Bossert  Switch  Adjuster,  Open  and  Closed. 
W.   F.   Bossert  Manufacturing   Company. 


Fig.    1529.     Cast-Iron   Rail   Brace   for   loo-lb.    Rail. 
Long  Island   Railroad. 


Fig.  1530.     Rail  Brace.     The  Cleveland  Frog  &  Cross- 
ing Company. 


1 88 


INTERLOCKING. 


Figs.  1531-1542 


Fig.   1531.     Switch   Adjustment.     Southern   Pacific-Union   Pacific. 

18. 


7  D 

Figs.    1532-1533.     Front   and    Lock   Rods. 


10     8 
Figs.  1534-1539 


Front  and  Lock  Rods. 


34 


7     6         5 

Names   of  Parts  of  Front  and  Lock 

Rods;   Figs.    1541-1542. 
A     Front   and   Lock   Rods   for  Double 

Slip  Switch 
B     Front  and  Lock  Rods  for  Movable 

Point  Frog 

1  Front  Rod 

2  Lock  Rod 

3  Left  Hand  Single  Point  Lug 

4  Right  Hand  Single  Point  Lug 

5  i%-in.   Jam  Nut 


Names   of   Parts   of  Front  and   Lock 
Rods;  Figs.  1532-1533. 

A     Front  and  Lock  Rod  for  Double 

Slip  Szi'itch 
D      Front  and  Lock  Rod  for  Szvitch 

with       Szvitch      and      Lock 

Movement 

1  Front  Rod 

2  Lock  Rod 

3  Left  Hand  Point  Lug 

4  Right  Hand  Point  Lug 

5  i/4"  Screw  Jaw 

6  il/2-in.  Jam  Nut 

7  7/s"  x  2^j"  Pin  and  Cotter 

8  iJ4-i».   Screw  Jazu 

11  Left  Hand  Point  Lug 

12  Right  Hand  Point  Lug 
18    5f  x  23/8"  C.  S.  H.  Bolt 

Names  of   Parts   of  Front  and  Lock 
Rods;  Figs.  I534-I539- 

Front   and   Lock    Rod    for   Double 

Slip  Switch 
Front   and  Lock   Rod  for  Movable 

Point  Frog 
Front    and    Lock    Rod    for    Single 

Switch 
D    Lock  Rod  for  Derail 

Front  and  Lock  Rod   for  Derail 
Front  and  Lock  Rod  Combined  for 

Inside   Connected  Facing  Point 

Lock 

Front  Rod  with  Turnbuckle 
Lock  Rod 

3  Left  Hand  Point  Lug 

4  Right  Hand  Point  Lug 
Point  Separator 

i -in.  Jam  Nut 
l-in.  Adjusting  Screzv 
1%-in.  Screzv  Jazu 
54"  x  ify$"  Rivet 
%"  x  2^8 "  Pin  and  Cotter     • 
Turnbuckle 
1%-in.  Jam  Nut 
Front  Rod 
Lock  Rod 
s/s"  x  2ft"  Bolt 
Left  Hand  Point  Lug 
17    Right  Hand  Point  Lug 
Right  Hand  Point  Lug 
Lock  Rod 
Front  Rod 

Left  Hand  Point  Lug 
Guide  Clip 
Hook  Bolt 
Front  and  Lock  Rod 
Right  or  Left  Hand  Point  Lug 


Fig.    1540.     Special   Front   Rod. 
4      6 


9 


B  5 

Figs.    1541-1542.     Front  and    Lock    Rods. 

6  i*4-m.    Screw  Jaw  8     54"  x  2^"  Bolt 

7  7/s"  x  2t/s"  Pin  and  Cotter  9     Front  Rod 


Figs.  i543-I56i 


INTERLOCKING. 


189 


disconnected  might  cause  a  dangerous  condition  at  the  switch 
without  being  discovered  at  once  by  the  signalman;  whereas, 
with  the  facing  point  lock,  if  the  pipe  line  which  throws  the 
switch  should  ln>coinr  disconnected,  the  signalman  would  be 
very  likely  to  discover  this,  and  remedy  it  before  any  train 
could  pass  over  the  switch. 


have  fixed  notches  or  may  be  adjustable  (Figs.  1522-1527 ». 
In  order  to  hold  switch  points  and  stock  rails  securely  In 
place  it  is  necessary  to  brace  the  rails  at  the  switch ;  also 
one  or  more  tie  plates  extending  across  the  tracks  are  fastened 
to  the  ties.  Fig.  1484  shows  these  fittings  applied  to  a  double 
slip  and  movable  point  frog.  Rail  braces  are  shown  in  Figs. 


Figs.   1543-1544.     Rail   Clips,   Detector  Bar  Stops  and  Detector   Bars. 

Switch  &  Signal  Company. 

Names  of  Parts  for  Detector  Bars,  Stops,  Guides  and  Rail  Clips;  Union  Switch  &  Signal  Company;  Figs.  1543-1544. 

Rail  Clip,  Model  I  4    Rail  Clip,  Model  4  15 

Rail  Clip,  Model  2  13     Adjustable  Stop  and  Guide 

Rail  Clip,  Model  3  14    Adjustable  Stop  with  Hook  Bolt 


The  Union 


Adjustable   Stop    with   Hook    or 
Web  Bolt 


Figs.     1545-1546.     Detector     Bar 
Stop  and  Guide,  to  be  Fast- 
ened   to    the    Tie. 


Figs.    1547-1548.      Detector    Bar 

Stop,  Bolted  Through  Web 

of  Rail. 


Figs.  1549-1550.    Adjustable  De- 
tector Bar   Stop  and  Guide, 
Clamped  to  Base  of  Rail. 


Figs.  1551-1552.     Adjustable  De- 
tector   Bar    Stop,    Clamped 
to    Base    of   Rail. 


rigs.    I553-I554-      Detector    Bar 

Stop      and      Guide,      Bolted 

Through  Web  of  Rail. 


Figs.  1555-1556.     Adjustable  De- 
tector   Bar    Stop,    Clamped 
to   Base  of   Rail. 


Figs.  I557-I559-     Malleable  Iron  Detector  Bar  Driv- 
ing Piece.     Michigan  Central. 

In  order  to  allow  for  lost  motion  and  future  adjustment,  the 
throw  in  the  pipe  line  which  moves  the  switch  is  usually  made 
greater  than  that  of  the  switch  itself.  To  provide  for  this 
over-stroke,  switch  adjustments  or  "cages"  (Figs.  1513-1521) 
are  used.  The  throw  rod  is  threaded  for  a  considerable  dis- 
tance and  passes  through  thimbles  in  the  "cage."  Nuts  are 
checked  up  against  each  side  of  the  thimbles  which  in  turn 
engage  the  "cage"  and  throw  the  switch.  Lock  rods  may 


Figs.    1560-1561.     Detector    Bar    Guide    and    Stop 


1528-1530.  This  construction  can  be  applied  equally  well  to 
a  single  switch.  In  the  drawing  the  rods  and  plates  are 
shown  insulated  for  track  circuits.  The  plates  are  made  of 
one-half  in.  by  six  in.  iron. 


DETECTOR  BARS. 

To  prevent  signalmen  from  throwing  switches  under  moving 
trains  detector  bars  are  employed.     A  detector  bar  IB  a  piece  of 


igo 


INTERLOCKING. 


Figs.  1562-1567 


u 


be 


U 


Co 


u     .  P4 

O      03 
-M      +->       C 

p! 

0  -offi 

•o   c 


c  pq 

OS 
-M     c/} 


O 
t-i     > 

^  E 
s* 


§s 

>»  c 

j'5 
i— I  n . 


rt 


PQ 


t?  > 

o 
bb 


Figs.  1568-1597 


INTERLOCKING. 


191 


4 


ill 

>v§ 

B5« 


o 


!|*  •$  '->  I 


«    x  *  ~\ 

"  j  CD    to    <D    r^ 

!?_1_1_U 


u 


_    j 


w^g 

5 


*15V. 


EUJLU 


LJJli 


(J  g 
CX 

1  1 

«  u 

« 1 

«  a 

u  CO 


IT'l 


CO 


n— 


J 


bo 


u 

'rt 


nSr> 


rtdrv 


LT^n 


«  — •  "^ 

O   rt  «- 

^      -M  ^ 

^r5.  § 

o>  U  +•• 


C     v    i- 

.2  «-§ 


^-i 
O     rt 

x  i 


•o  -o 


IQ2 


INTERLOCKING. 


Figs.  1598-1603 


Iron  lying  along  the  rail.  It  is  held  in  place  by  clips  and 
guides  (Figs.  1545-1597),  so  that  whenever  it  is  moved  length- 
wise the  top  of  it  rises  above  the  head  of  the  rail.  With 
such  an  arrangement  it  will  be  seen  that  if  an  attempt  is 


facing  point  lock,  or  by  the  operating  rod  of  a  switch  and 
lock  movement.  Therefore  the  bar  must  rise  at  the  same  time 
the  switch  is  being  unlocked.  Various  arrangements  of  de- 
tector bars  at  switches  are  shown  in  Figs.  1480-1485  and  1562- 


Figs.  1598-1600.     Outside  Parallel   Bar   (Detector    Bar).      Greai 
Western    Railway    of    England. 


•  ^i:-.--m  ~ 

r   "i 

1-                _|       -H 

-j 

L     1     J        ' 

1    !               ! 

1           <     1 

r-  —  [^ 

3 

Figs.    1601-1603.      Inside    Parallel    Bar.     Great    Western    Railway    of    England. 


made  to  move  the  bar  while  one  or  more  wheels  of  a  train 
are  on  the  track  at  that  point,  the  bar  will  strike  against 
the  wheels  and  cannot  be  thrown.  Detector  bars  are  made 
longer  than  the  maximum  distance  between  the  wheels  of  a 
car  In  order  that  they  may  not  rise  between  trucks.  The  bar 
Is  actuated  by  the  same  rod  that  operates  the  plunger  of  a 


1567.  The  bar  should  always  be  put  on  the  high  side  of  a 
curve  as  centrifugal  force  tends  to  throw  the  wheels  of  a 
train  toward  that  side.  Where  a  bar  cannot  be  placed  ahead 
of  a  switch,  two  bars  must  be  used  as  shown  in  Figs.  1480-1483, 
1564-1567,  one  on  each  track,  thereby  insuring  that  it 
will  be  impossible  to  unlock  the  switch  when  either  track  is 


Figs.  1604-1617 


INTERLOCKING. 


193 


occupied.  The  detector  bars  may  be  driven  from  cranks 
(Figs.  1479-1482  and  1484-1485)  or  from  rocker  shaft  suspended 
below  the  rails.  (Fig.  1483.) 

Fig.  1562  shows  a  device  for  operating  one  detector 
bar  in  connection  with  two  switch  and  lock  movements.  At 
each  end  of  the  rocker  shaft  are  arms  connected  to  links,  the 
upper  ends  of  which  travel  in  guides  A  and  B,  and  are  driven 
by  the  switch  and  lock  movements.  The  action  of  the  device 
can  clearly  be  seen  by  reference  to  the  small  diagrams.  The 
bar  in  this  case  moves  from  its  normal  position  to  the  center 
of  the  stroke  and  back,  never  going  to  the  full  reverse  position. 


'  FEDERAL  SWITCH  GUARD. 

The  Federal  switch  guard  consists  of  an  angle  iron  held  in 
proper  relation  to  the  rail  by  specially  designed  guides.  The 
upper  or  horizontal  leg  of  the  angle  has  its  edge  in  contact 
with  the  head  of  the  rail  and  slightly  below  the  top  of  it. 


Figs.   1604-1607.      Federal    Switch   Guard. 


Before  the  switch  to  which  the  guard  is  attached  can  be 
operated  or  even  unlocked,  the  angle  iron  must  be  raised 
above  the  top  of  the  rail  and  then  moved  inward,  the  vertical 
motion  being  three-quarters  of  an  inch  and  the  horizontal  one 
Inch.  This  movement  insures  the  proper  protection  even 
under  conditions  which  would  cause  the  ordinary  detector  bar 
to  fail.  The  use  of  special  rail  braces  used  with  detector 
bars  Is  unnecessary,  as  there  is  ample  room  between  vertical 
leg  of  angle  and  head  of  rail  for  any  rail  brace. 


THE   UNION   SPIRAL   SWITCH   GUARD. 

The  general  construction  of  this  guard  shown   in  Figs.   1608, 
1609,   and   1610    is    the  same   as   the   motion    plate    detector   bar 


Fig.  1608.     Spiral  Switch  Guard.    Union  Switch  & 
Signal   Company. 


in  general  use,  but  its  motion  in  operation  is  that  of  a 
spiral  instead  of  an  inclined  plane.  The  form  of  the  motion 
plate  is  such  that  the  b.i.r  is  caused  to  advance  along  the  side 
of  the  rail  and  at  the  same  time  and  by  the  same  movement 
pass  upward  and  over  the  top  of  the  rail. 


Figs.    1609-1610.     Spiral   Switch   Guard. 


Fig.  1611.     Combination  Detector  Bar  Clip. 


Figs.   1612-1613.     Combination   Detector  Bar  Rail  Clip. 


Figs.    1614-1615.     Detector    Bar    Rail    Clip    Fastened   with 
Web  Bolts. 


Figs.   1616-1617.     Motion  Plate  Detector  Bar  Rail  Clip. 

Wrought  Iron  Type.     Union   Switch  and  Signal 
Company. 


If  a  car  wheel  is  on  the  rail,  at  the  time  an  attempt  is  made 
to  move  the  bar,  whose  flange  projects  beyond  the  rail  head, 
the  motion  of  the  bar  will  be  arrested  as  soon  as  it  comes  In 
contact  with  the  wheel  tread.  If,  however,  owing  to  excessive 
width  of  gauge  from  worn  wheels  and  rails,  the  outer  face 
of  the  wheel  does  not  project  beyond  the  rail,  the  spiral  motion 
of  the  bar  will  bring  it  in  contact  with  the  face  of  the  wheel 
and  the  further  motion  of  the  bar  will  be  prevented. 


194 


INTERLOCKING. 


Figs.  1618-1620 


Fig.    1618.     Details   of   Interlocked 

Switch.      Atchison,    Top-'ka 

&  Santa  Fe. 


Fig.    1619.     Details   of   Split    Point 

Derail.     Atchison,  Topeka 

&  Santa  Fe. 


12 


13 


10 


15 


13 


Fig.  1620.      Xickerson  Single  Lever  Safety    Switch  Lock.     W.   F.  Bossert  Manufacturing  Company 


Figs.  1621-1625 


INTERLOCKING. 


195 


DERAILS. 

V'hon  it  is  desired  to  be  sure  that  n  train  will  not  run  past 
a  stop  signal  (as  in  the  case  of  grade  crossings,  drawbridges, 
etc.),  it  is  customary  to  provide  means  of  derailing  the  train 
if  it  should  do  so,  by  using  some  form  of  derailing  switch. 
This  often  consists  of  one-half  of  an  ordinary  split  point 
switch;  that  is,  the  half  that  is  closed  for  main  track  move- 
ments, the  other  side  of  the  track  being  a  continuous  rail. 
Other  ways  of  accomplishing  the  same  result,  involve  a  rail 


bottom  which  rests  over  the  rail  head  and  takes  the  lateral 
thrust.  Connection  is  made  to  the  operating  apparatus  through 
a  centrally  pivoted  lever  whoso  upper  end  carries  a  lug  acting 
in  a  cam  slot  on  the  side  of  the  block.  This  also  takes  care 
of  any  overstroke  in  the  connections. 

FRKELAND   CLAMP  DERAILS. 

The    Freeland    clamp    derailers    made    by    The    Hobart-Allfree 
Co.  are  furnished  with  two  special  st;rew  jaws  with  interlocking 


Fig.  1621.     Freeland  Mechanical  Throw  Derailers 

No.  7. 


Fig.    1622.     Freeland   Mechanical  Throw   Derailers, 
No.  8. 


Fig.    1623.      Installation   of  Freeland    Derailer   on   the    Northern   Pacific. 


which  is  brought  against  the  gauge  line  to  deflect  the  wheel 
flange,  the  opposite  flange  being  raised  over  the  ball  of  the  rail 
by  an  inclined  rail  which  catches  the  overhang  of  the  tread, 
and  raises  it  so  that  the  flange  clears.  Derails  of  this  type  are 
known  as  "unbroken  rail  derails." 


pins.  All  derails  have  a  lip  or  flange  which  engages  the 
head  of  the  rail  and  relieves  the  supporting  brackets  of  the  side 
thrust  imparted  to  the  derailing  block  at  the  time  of  the  de- 
railment. When  the  Freeland  derailers  are  in  th'e  open  position 
and  the  track  is  clear  the  derailing  block  falls  into  pockets 


Fig.     1624.       Lifting     Derail. 
Railroad  Supply  Company. 


Fig.    1625.      Anderson-Bevan    Derail.      General    Signal    Company, 


The  Anderson-Bevan  derail  (Fig.  1625)  made  by  the  (Jcnernl 
Railway  Signal  Co.  consists  of  a  derailing  block  mounted  in  a 
stand  designed  to  be  fastened  to  a  tie.  The  block  is  car- 
ried on  an  arm  pivoted  in  the  stand  so  that  it  can  swing 
OTI  and  off  of  the  rail.  The  block  has  a  channel  in  the 


formed  by  the  base.  The  derailer  No.  7  is  2  ft.  8  in.  long, 
weighs  165  Ibs.  and  may  be  operated  by  switch  stand  or  from 
the  interlocking  plant.  The  No.  8  derailer  is  20  in.  long  and 
weighs  125  Ibs.  The  Freeland  clamp  derailers  are  designed  for 
mechanical  throw,  and  the  Smyth  derailers  for  hand  throw. 


ig6 


INTERLOCKING. 


Figs.  1626-1628 


THE    HAYES    DERAIL. 

The  Hayes  derail  (Figs.  1626-1638)  consists  of  two  parts,  the 
derail  block  and  the  guide  box.  Both  parts  are  malleable 
castings.  Figs.  1629-1636  show  successive  positions  of  the 
derail  block  while  it  is  being  moved  from  the  open  to  the 
closed  position.  In  the  line  drawings  (Figs.  1630-32-34-36} 
the  derail  block  is  shown  in  heavy  shading.  This  derail  block 
carries  four  round  pins,  two  on  each  side.  These  pins  slide  in 
the  cam  slots  in  the  guide  box  and  serve  to  guide  the  derail 


ried  by'  these  same  lugs  on  the  derail  block  to  the  side  walls 
of  the  guide  box  and  thence  to  the  ties.  There  are  two  lugs 
at  the  back  end  of  the  derail  block  with  holes  for  attaching  to 
operating  and  locking  devices.  Fig.  1628  is  a  view  of  the  de- 
rail just  described,  in  track.  Fig.  1627  is  a  similar  design,  but 
has  a  reversible  eyebolt  between  the  two  back  lugs,  affording 
three  connections  to  the  derail  block,  one  for  the  operating  rod, 
one  for  a  facing  point  lock  and  the  third  for  a  wire  bolt  lock. 
Fig.  1638  shows  a  different  model  designed  to  be  operated  by 


[626.     Hayes   Derail,   Model   C.     Open. 


Fig.  1627.     Hayes  Derail.    Model  CP,  with  Extra  Connection  for  Bolt  Lock. 


Fig.   1628.     Hayes  Derail,  Model  C,  Operated  by  Motor. 


block  up,  over  and  down  awa.v  from  the  rail.  The  lugs  at  the 
front  end  of  the  derail  block  next  to  the  rail  rest  against 
seats  in  the  guide  box  when  the  derail  is  open  or  on  the  rail. 
These  seats  hold  the  derail  block  from  leaving  the  rail  except 
by  rising  above  it  at  the  same  time.  The  thrust  at  right  angles 
to  the  rail  of  a  wheel  encountering  the  derail  block  is  carried 
by  these  seats  in  the  guide  box  to  the  ties  and  roadbed.  The 
weight  of  a  wheel  passing  over  the  block  serves  to  hold  the 
derail  more  firmly  in  place.  Thrust  parallel  to  the  rail  is  car- 


hand  only.  It  cannot  be  attached  to  an  operating  rod.  The 
two  castings  are  joined  by  a  piece  of  cold-rolled  steel  shafting, 
riveted  in  place.  Hayes  derails  are  made  in  five  styles,  being 
models  A,  AF,  C,  CP  and  CX  for  operation  by  pipe  line  or 
switch  stand.  They  are  made  in  three  styles,  models  D,  B,  and 
EX  for  hand  operation.  Hayes  derails  are  made  in  three 
sizes  :  size  4  is  for  use  on  rail  from  three  to  four  inches  high  ; 
size  5  is  for  use  on  rail  over  four  and  up  to  five  inches  high  ; 
sine  6  is  for  use  on  rail  more  than  five  inches  high. 


Figs.  1629-1638 


INTERLOCKING. 


197 


Figs.   1629-1630.     Derail  Open. 


Figs.   1631-1632.     Derail   Block  Leaving  Front  Seats. 


Figs.   1633-1634.     Derail    Block   Falling   Past   Head   of   Rail. 


Figs.     1635-1636.     Derail     Closed. 
Figs.  1629-1636.     Hayes  Derail  in  Successive  Positions. 


Fig.    1637.     Hayes   Derail,   Model   C,  with   Operating  Stand. 


Fig.  1638.     Hayes   Derail,   Model  E,   Hand   Operated  Type,  Open. 


ig8 


INTERLOCKING. 


Figs.  1639-1646 


SIGNALS. 


Figs.  1639-1640.     Pipe  FIRS.    1641-1642.   Wire        Figs.  1643-1644.     Pipe  Figs.  1645-1646.    Wire 

Connected.  Connected.  Connected.  Connected. 

One  Arm.  Two  Arm. 

Figs.    1639-1646.     Iron    Post    Mechanical    Interlocking    Signals. 


Names  of  Parts,  One  Arm  Iron  Pipe  Post  Mechanical  Interlocking  Signal;    Figs.  1639-1642. 


1  Iron  Pipe  Post 

2  Blade 

3  Semaphore  Rearing 

4  Spectacle 

5  Back  Spectacle 

6  Semaphore  Shaft 

7  Lamp  Bracket 

8  Lamp   Bracket   Clamp 

9  Ladder 


10  Ladder  Clamp 

11  Ladder  Stay 

12  Ladder  Stay 

13  Ladder  Stay 

14  Ladder  Foundation 

15  Pipe  Guide 

16  Pipe  Guide 

17  Up  and  Down  Rod 

18  Up  and  Doivn  Rod 


19  Balance  Lever  Stand  with  Clamp 

for  Prpe  Connected  Signal 
igA  Balance  Lever  Stand  with  Clamp 
for   Wire   Connected  Signal. 

20  Screw  Jaw 

21  Pinnacle 

22  Signal  Wheel  Clamp 

23  Signal    Wheel 

24  Ladder  Stay  Bolt 


Names  of  Parts,  Two  Arm  Iron  Pipe  Post  Mechanical  Interlocking  Signal;   Figs.  1643-1646. 


1  Iron  Pipe  Post 

2  Blade 

3  Semaphore  Bearing 

4  Spectacle 

5  Back  Spectacle 

6  Semaphore  Shaft 

7  Lamp  Bracket 

8  Lamp  Bracket  Clamp 
g  Ladder 

10  Ladder  Clamp 

11  Ladder  Stay 


20 


Ladder  Stay 

Ladder  Stay 

Ladder  Stay 

Ladder  Foundation 

One  Way  Pipe  Guide 

Two  Way  Pipe  Guide 

Two  Way  Pipe  Guide 

Up    and   Down    Rods    for   Pipe 

Connected    Signal 
Up    and   Down-  Rods   for   Wire 

Connected  Signal 


23 
24 

25 
26 

27 


Two  Way  Balance  Lever  Stand 
with  Clamp  for  Wire  Con- 
nected Signal 

Two  Way  Balance  Lever  Stand 
with  Clamp  for  Wire  Con- 
nected Signal 

Two  Way  Signal  Wheel 

Signal  Wheel  Clamp 

Pinnacle 

Screw  Jaw 

Ladder  Stay  Bolt 


Figs.  1647-1671 


INTERLOCKING. 


199 


x  V 


Figs.   1647-1661.      Clamps  and  Clamp  Crank  Stands  for  Iron 

Pipe  Posts. 

4 


Figs.    1662-1663.     Balance    Levers. 


Figs.  1664-1665.     Special  Dwarf  Signal  Movement. 

7 


Figs.   1666-1667.     Low  Pot  Signal. 

Names  of  Parts,  Two-Arm 

Dwarf  Signal  with  Restoring 

Springs;   Figs.   1668-1671. 


1  Combination  Base  and  Pole 

2  Tivo  Way  Crank  Stand 

3  Loiver  Semaphore  Bearing 

4  Spectacle 

5  Semaphore  Shaft 

6  Blade 

7  Pinnacle 

8  Back  Spectacle 

9  Up  and  Down  Rod 
10  Lamp  Bracket 

n  Escapement  Crank 

12  Screzv  Jaw 

13  Pin 

14  Tzc'o  Way  Guide  Stand 

15  Pm  with  Cotters 

18  Operating  Shaft  with  Eye 

19  Spring  Plate 

20  Spring 

21  Trunnion  Block 

22  Double  Lug 

23  6-iH.  Chain  Wheel  and  Stand 

25  Ta/>  So/f 

26  ra 


Figs.  1668-1671.     Two-Arm  Dwarf  Signal,  with  Restoring  Springs. 


Names  of  Parts,  Special  Dwarf 
Signal    Movement;    Figs. 
1664-1665. 

1  Stand 

2  Stud  ivith  Cotter 

3  Escapement  Crank 

4  Trunnion 

5  Trunnion  Cap 

6  Bolt 

7  Rivet 


Names  of  Parts  of  Low  Pot 
Signal;  Figs.  1666-1667. 

1  Stand 

2  Crank 

3  Crank  Shaft 

4  Lamp  Base 

5  Tap  Bolt 

6  Stop  Target 

7  Clear  Target 


200 


INTERLOCKING. 


Figs.  1672-1683 


Names  of  Parts,  Dwarf 

1  Iron  Pipe  Post 

2  Iron  Pipe  Post 

3  Semaphore  Bearing 

4  Blade 

5  Semaphore  Bearing 

6  Spectacle 

7  Semaphore  Shaft 

8  Back  Spectacle 

9  Lamp  Bracket 


Signals;   Figs.   1672-1675 

Up  and  Down  Rod 

Up  and  Down  Rod 

Base 

Pin 

Balance  Lever 

Counterweight 

Counterweight  Bolt 

Screiv  Jaiv 


5.  ,8 


Figs.    1672-1673.     One-Arm   Dwarf  Signal. 


Figs.   1674-1675.     Two-Arm  Dwarf  Signal. 


f 


Figs.   1676-1679.     One-Arm  Dwarf  Signal,  with   Spring 
Restoring    Attachment. 


Names  of  Parts,  One-Arm  Dwarf  Signals  with  Spring 
Attachment;  Figs.  1676-1679. 


Post  and  Base 
Crank  Bearing 
Semaphore  Bearing 
Spectacle 
Semaphore  Shaft 
Blade 
Disc- 
Back  Spectacle 
Up  and  DoTun  Rod 


ii 

12 


Escapement  Crank 
Center  Pin 


13  Screw  Jaw 

14  Guide  Stand 

15  Pin  and  Cotter 

16  Roller 

18  Operating  Shaft 

19  Spring  Plate 

20  Spring 

21  Trunnion  Block 

22  Double  Lug 

23  6-in.   Wheel  and  Stand 

25  Tap  Bolt 

26  Tap  Bolt 


Figs.    1682-1683.      Switch    Light    Stand. 


Names  of  Parts,  Switch  Light  Stand;  Figs.   1682-1683. 

Figs.  1680-1681.     45  deg.  Upper  Quadrant  Union  Dwarf        i     Stand  3     Lamp  Spindle 

Signal    Spring    Attachment.  •     2     Crank  Arm  4    Dowel  Pin 


Figs.  1684-1691 


INTERLOCKING. 


2OI 


Figs.  1684-1685.     Single  Dwarf  Signal  and  Point  Detector    Combined.      Great    Western    of    England. 


Names  of  Parts,  High 

and  Low  Pot  Sig- 
nals;   Figs.    1687-1689. 

Stand 

Top  Bearing  Bushing 

Collar 

Vertical  Shaft 

Lamp  Base 

Crank  Bushing 

Adjustable  Eye  Bolt 

Tap  Bolt 

Stop  Target 

Clear  Target 


Fig.   1686.     Compensating  Dwarf  Signal. 


Figs.    1687-1689.     Types  of  Pot   Signals. 


Figs.    1690-1691.      Compensating    Pot    Signal,    Johnson 
Type. 


Names   of   Parts,   Compensating   Pot   Signal,   Johnson 
Type;  Figs.  1690-1691. 

1  Stand 

2  Stud 

3  Lamp  Base 

4  Set  Screw 

5  Balance  Lever 

6  Pin 

7  Roller 

8  Counterweight 

9  Stop  Bolt 
10    Dowel  Pin 


2O2 


INTERLOCKING. 


Figs.  1692-1702 


Three  Lever 

'    D^crrf/nf:  Machine 


'Q-  Two  No.9  Steel  Signal  Wires. 


Figs.    1692-1695.     Layout  and   Detail   of   Distant   Switch    Signal 

and    Facing    Point    Lock,    Operated    by    Double    Lever 

Switch  Stand.    New  York  Central. 


Figs.  1696-1698.    One  Signal  Operated  from  Two  Switches; 

Details  of  Construction.     Nashville,  Chattanooga 

&  St.  Louis. 


terweight. 


Fig.  1699.     Electro-Pneumatic  High  Signal,  Fitted 

to  be  Operated   by  Wire.     Pennsylvania 

Railroad. 


Fig.     1701.       Electro-Pneumatic     Dwarf 

Signal   Fitted  for   Pipe   Operation. 

Pennsylvania   Railroad. 


Fig.      1702.       Electro-Pneumatic     Dwarf 

Signal,    Adapted    to    be    Worked    by 

Wire.     Pennsylvania  Railroad. 

NOTE. — Pigs.  1548  and  1552-1553  show  how  electro- 
pneumatic  signals  with  mechanism  removed  may  be 
•perated  as  mechanical  signals. 


LJLJLJU 


Figs.  1703-1709 


INTERLOCKING. 


203 


Names  of  Parts  of  Distant  Switch  Signal;  Figs.  1703-1705. 

1  Wooden  Post 

2  Ladder 

3  Ladder  Foundation 

4  Spectacle 

6  Blade 

7  Up  and  Down  Rod 

8  Balance  Lever  and  Stand 

9  Signal  Wheel  and  Stand 


rigs.   1703-1705.     Distant  Switch   Signal,  Wire   Connected  and  Operated  by  Ground  Lever  and  Rim  Lock.    Union 

Switch  &  Signal  Company. 


Compensator  Set  on  \          » 
Concrete  foundation. 


U   U   U   J   U 


UU  TU 


Fig.  1706.     Layout  for  Pipe  Connected  Distant  Switch  Signal   and    Facing    Point    Lock.      New   York,    Ontario    & 

Western. 


BOLT    LOCKS. 

It  is  customary  to  bolt  lock  all  high  speed  signals  with 
facing  point  switches  in  the  route  governed,  so  that  should 
the  switch  be  set  wrong  or  be  partially  open,  on  account  of 
broken  switch  or  facing  point  lock  connections,  the  signal  could 


not  be  cleared.  A  bolt  lock  (Figs.  1710-1725)  consists  of  two 
notched  bars  working  at  right  angles  to  each  other  in  a 
frame.  One  rod  is  connected  to  the  switch  point  and  the 
other  forms  part  of  the  line  to  the  signal.  The  notches  are 
so  arranged  that  unless  the  switch  is  set  right  the  signal  bar 


Figs.    1707-1709.     Point   Detector  or   Bolt   Lock.   Great  Western   Railway  of  England. 


204 


INTERLOCKING. 


Figs.  1710-1725 


9 


13 


Figs.  1710-1721.     Bolt  Locks. 

P-P 


Names  of  Parts,  Bolt  Locks; 

Figs.   1710-1721. 
A     One-Way     Bolt     Lock,     Pipe 

Connected 
B     Two-Way     Bolt     Lock,     Pipe 

Connected 
C     Three-Way    Bolt    Lock,    Pipe 

Connected 
D     One-Way    Bolt    Lock,     Wire 

Connected 
E     Tzvo-Way    Bolt    Lock,    Wire 

Connected 
F     Three-Way  Bolt   Lock,    Wire 

Connected 

1  One-Way  Stand 

2  Two-Way  Stand 

3  Three-Way  Stand 

4  Switch-Bar  for  One  or  Two 

Way  Stand 

5  Stmtch-Bar     for     Three-Way 

Stand 

6  Signal-Bar  for  Pipe   Connec- 

tion 

7  Signal-Bar  for  Pipe   Connec- 

tion, Right-Hand  Beveled 

8  Signal-Bar  for  Pipe  Connec- 

tion,   Left-Hand    Beveled 

9  Signal-Bar  for  Wire  Connec- 

tion 

10  Signal-Bar  for  Wire  Connec- 

tion, Right-Hand  Beveled 

11  Signal-Bar  for  Wire  Connec- 

tion,   Left-Hand    Beveled 

12  Shackle 

13  Pin 
15     Cotter 


^.._____ 


-H 


/  (< (. 


t" 


(Q  H      L  -T 

o) 

11 


J__J1 


._JL 


Figs.    1722-1725.      Two-Way    Bolt  Lock    Details.      Michigan    Central. 


Figs.  1726-1733 


INTERLOCKING. 


205 


o 

f^vM        ,                                /Oi 

[ 

^a^^^^^^^^^^^^^^^sy. 

i  B! 

M  _  j__4_   \_j  w  i                                                                            T     T"I"fr 

01. 

TTl 

rvj-T  ^  ^i         ""~"T  rfrS 

Figs.     1726-1728.      Point    Detector 

and  Restorer.     Great  Western 

Railway    of    England. 

Names  of  Parts,  Point  Detector  and 
Restorer;  Figs.  1726-1728. 
A    Facing  Point  Lock  Bar 
B     Block  in  A 
C    Signal  Bar 
D     Block  in  C 
E    Switch  Bar 


TT           'r"iu;            nr 

^" 

4J—                     .'1               r4- 

,''8 

-Ln^  —  ^ 

j/      '  '    nj/ 

Figs.   1729-1731.     Ground    Lock.     Great 


cannot  move,  and  after  the  signal  has  been  cleared  its  bar 
locks  the  switch  bar  so  that  the  switch  cannot  be  moved 
until  the  signal  has  been  restored  to  the  normal  position. 

An  English  device,  known  as  a  "point  detector  and  restorer," 
is  shown  in  Figs.  1726-1728.  It  is  essentially  a  bolt  lock  for 
use  with  wire  connected  signals  when  only  one  wire  is  used. 
B  is  the  bar  attached  to  the  switch  point,  having  a  notch 
and  interlocking  with  notched  bar  C  as  in  American  practice. 
C  is  connected  in  the  signal  line.  Bar  A  is  operated  by  the 
pipe  line  for  the  facing  point  lock.  Block  D  is  set  into  a  notch 
In  bar  C,  and  block  B  into  a  notch  in  bar  A.  When  the 
switch  is  locked  bar  A  is  pushed  in,  carrying  block  B  with 
it.  The  signal  can  then  be  cleared.  If,  when  the  signal 
lever  is  put  normal,  the  bar  C  should  not  make  sufficient  stroke 
to  release  E,  the  block  B  would  strike  against  block  D  when 
the  switch  was  unlocked,  thus  forcing  C  through  the  re- 
mainder of  its  stroke  and  releasing  E.  This  device  therefore 
automatically  overcomes  the  effects  of  contraction  between  the 
lever  and  the  bolt  lock,  and  of  slack  wire  between  the  bolt 
lock  and  the  signal. 


Where  it  is  desired  to  control  one  signal  from  two  interlock- 
ing machines  mechanically,  a  slot  such  as  is  shown  in  Figs. 
1734-1735,  may  be  used.  This  consists  of  a  slide  2  moving 
in  guides  on  casting  1,  the  latter  being  fastened  to  the  signal 
post.  Two  vertical  rods,  one  operated  from  each  interlocking 
machine,  move  in  2.  The  connection  to  the  semaphore  casting 
is  attached  to  the  top  of  2.  The  vertical  rods  strike  against 
roller  8  when  raised.  If  only  one  rod  is  raised  the  roller  will 
move  to  one  side  out  of  its  path;  but  if  both  are  raised  to- 
gether, or  one  is  raised  while  the  other  is  already  up,  the 
roller  will  strike  against  the  lug  above  it  and  the  whole  slide 
2  will  move  upward  and  clear  the  signal.  Stops  5  engage  the 
bottom  of  slide  2  and  assure  its  return  to  normal  position 
when  either  rod  is  lowered.  Lug  4  is  used  when  the  slot  i» 
applied  to  a  double  arm  home  and  distant  signal,  when  the 
home  is  controlled  from  one  point  and  the  distant  from  an- 


other. The  home  signal  is  actuated  by  a  rod  attached  to  4 
and  the  distant  signal  by  a  rod  attached  to  the  top  of  2.  Thus 
(he  distant  arm  cannot  be  cleared  while  the  home  arm  is  in 
the  stop  position.  Another  style  of  mechanical  slot  is  shown 
in  Figs.  1732-1733.  The  case  1  is  fastened  to  the  signal  pole. 
Rods  5  and  6  move  through  the  case  which  acts  as  a  guide. 


Names  of  Parts,  Johnson 
Type  Mechanical  Slot; 
Figs.   I732-I733- 

2  Slot  Case  and  Cover 

5  Left  Hand  Vertical  Slide 

6  Right  Hand  Vertical  Slide 

7  Coupling  Rod 

8  Roller 


(2) 

Figs.   1732-1733.     Mechan- 
ical  Slot.     Johnson 
Type. 


2O6 


INTERLOCKING. 


Figs.  1734-1741 


Names  of  Parts,  Mechanical  Slot;  Figs.  I734-I735- 


Slot  Guide 

Slide 

Tap  Bolt 

Right  Hand  Vertical  Slide 

Rivet  Stop 

Screw  Jaw 

Connecting  Rod 


Roller 
Cover 


Figs.    1734-1735.      Mechanical   Slot. 

The  signal  up  and  down  rod  is  attached  to  the  swing  jaw, 
which  is  equipped  with  two  rollers  8  and  a  trangular  lug. 
Dogs  at  top  of  rods  5  and  6  strike  against  the  rollers  when 
raised.  Raising  of  one  rod  only  pushes  8  over  to  the  other 


DRAWBRIDGE   INTERLOCKING. 

Drawbridge  protection  by  interlocking  involves  some  special 
devices.  Couplers  must  be  provided  to  make  the  pipe  line  con- 
tinuous from  shore  to  bridge.  These  consist  of  hooks  and  sock- 
ets mounted  in  frames  (Figs.  1742-1744).  One  frame  contains 
a  hinged  member  for  raising  the  sockets  from  engagement  with 
the  hooks.  A  separate  lever  may  be  used  to  disengage  the  line, 
or  the  same  lever  that  unlocks  the  bridge  may  be  employed. 
It  is  not  customary  to  carry  wire  on  the  bridge  deck.  Where 
wire  is  used  the  line  is  changed  to  pipe  on  the  bridge  (Figs. 
1745-1746).  Usually  clearances  on  bridges  will  not  permit  the 
use  of  horizontal  compensators,  so  vertical  compensators  are 
employed.  Safety  demands  that  the  bridge  be  locked  in  align- 
ment and  the  rails  in  place  before  the  signals  can  be  cleared. 

Figs.    1736-1738   illustrate  a  tumbler  drawbridge  lock  for  lift 


]—  B 

a-  c 

0      0 

^  o     o 

TS».-V™ 

Figs.    1736-1738.     Tumbler  Bridge   Lock. 

Names   of   Parts    of   Tumbler   Bridge   Lock; 
Figs.  1736-1738. 

A  Releasing  Stand 

B  Stud 

C  Pin 

D  Plunger 

E  Plunger  Casting 

F  Locking  Tumbler 

bridges.  Casting  A  is  carried  on  the  bridge  and  to  it  is  fast- 
ened a  stud  B  fitting  in  a  notch  of  the  locking  tumbler  F. 
This  tumbler  is  pivoted  on  plunger  casting  F.  The  stud  B 
raises  F  when  the  bridge  is  closed.  When  the  bridge  opens 


(on 


E/  A 

Fig-   I739-I74L     Automatic  Bridge  Coupler. 


Names  of  Parts,  Automatic 
Bridge  Coupler;  Figs.  1739-1741. 
A    Stud 

K     B     Abutment  Casting  and  Guide 
C    Hook  Bar 
D    Stop  Bolt 
E    Stud 
F    Spider 
G    Base  Plate 
H     Engaging  Slide 
K     Coupler  Casting 


side  and  does  not  affect  the  signal.  Raising  of  both  rods  to- 
gether or  separately  raises  the  up  and  down  rod  and  clears 
the  signal.  Dogs  on  the  ends  of  rods  5  and  6  engage  with  the 
triangular  lug  to  insure  that  the  signal  will  be  restored  to  the 
stop  position  when  either  rod  is  lowered.  The  upper  end  of 
rod  6  is  equipped  with  a  lug  to  which  the  home  signal  is 
attached  when  home  and  distant  are  on  same  pole,  as  explained 
in  connection  with  Figs.  1734-1735. 


the  locking  tumbler  drops  into  the  slot  in  front  of  the  plunger, 
thereby  preventing  its  passage  all  the  way  through  E.  This 
device  acts  as  a  check  on  the  rail  lock  or  the  releasing  lever, 
as  it  is  necessary  for  the  plunger  to  pass  through  E  before 
either  of  the  above  can  act. 

Figs.  1747-1749  illustrate  a  device  for  the  same  purpose  as 
Figs.  1736-1738  applied  to  a  swing  bridge.  Casting  B  is  fast- 
ened to  the  bridge  and  casting  C  to  the  shore.  Escapement 


Figs.  1742-1744 


INTERLOCKING. 


207 


lock  F  is  pivoted  to  C  and  is  engaged  by  a  stud  D  on  B  to 
move  it  so  that  the  notch  comes  opposite  to  the  plunger  open- 
ing when  the  bridge  is  closed.  V.'hen  the  bridge  opens  F  is 
moved  in  front  of  the  plunger  and  blocks  it.  Figs.  1755-1757 
show  a  similar  device.  The  plunger  here  is  very  heavy  and  is 
designed  to  lock  the  bridge  against  movement  if  desired.  The 
locking  block  D  is  moved  to  one  side  by  a  stud  on  casting  E. 
Figs.  1753-1754  show  a  device  designed  for  locking  swing 
bridges.  Here  the  tappet  K  works  with  the  apparatus  on  the 


dogs  1  (Figs.  1750  and  1752)  normally  occupy  the  position  A 
(Fig.  1751).  When  unlocked  the  dogs  allow  themselves  to  be 
raised  by  the  lifting  of  the  rail  to  the  position  B,  locking  the  lug 
2  and  rocker  shaft  3  in  the  reverse  position.  When  the  rail  Is 
again  lowered  it  restores  the  dogs  to  their  normal  position, 
allowing  2  and  3  to  revolve  and  securely  lock  the  rail  in  place. 
An  automatic  bridge  coupler  for  swing  bridges  is  shown  in 
Figs.  1739-1741.  Casting  K  is  mounted  on  the  bridge  and 
casting  B  on  the  abutment.  K  is  provided  with  slotted  bolt 


i! 


u 


)  i 


Fig.   1742-1744.     Multiple  Bridge  Coupler. 


bridge,  while  the  plunger  C  is  operated  from  the  shore  and 
holds  the  tappet  against  withdrawal.  The  tappet  is  guided  by 
a  box  and  rests  on  spring  P,  which  absorbs  shocks.  It  carries 
at  its  extremity  a  pin  A  which  engages  escapement  jaw  M, 
this  jaw  being  pivoted  in  the  plunger  box  B.  When  the  tappet 
is  withdrawn  the  stud  pulls  the  escapement  jaw  in  front  of 
the  plunger  hole,  where  it  remains  blocking  the  plunger  until 
the  tappet  is  again  inserted.  Figs.  1758-1761  show  bridge  rail 
locks.  They  are  used  to  lock  the  bridge  rails  in  place.  They 
consist  of  a  modification  of  an  inside  connected  facing  point 
lock.  The  plunger  capping  has  an  opening  through  which  a 
tongue  fastened  to  the  front  rod  passes.  This  tongue  blocks 
the  plunger  when  the  rails  are  raised. 
Figs.  1750-1752  show  another  type  of  rail  lock.  The  rail 


holes  for  adjustment.  On  B  is  mounted  a  spider  F,  which 
revolves  on  a  stud  E  through  its  center.  It  is  provided  with 
four  dogs  on  its  upper  surface  and  has  four  notches  in  its 
circumference  between  the  dogs.  The  pin  A  on  K  engages  in 
one  of  the  notches  and  holds  the  spider  in  position  shown  when 
the  bridge  is  closed.  When  the  bridge  is  opened  the  pin 
moves  the  spider  through  an  angle  of  45  degrees.  In  this  posi- 
tion  two  of  the  dogs  on  the  spider  engage  the  two  dogs  on  the 
lower  surface  of  hook  bar  C  which  forms  the  shore  end  of  the 
pipe  line.  Engaging  slide  H  forms  the  bridge  end  of  the  pipe 
line:  its  end  is  bent  as  shown  and  engages  the  end  of  the  hook 
bar.  This  makes  the  pipe  line  continuous  from  shore  to  bridge. 
Figs.  1745-1746  and  1758-1761  show  applications  of  some  of 
the  apparatus  just  described. 


208 


INTERLOCKING. 


Figs.  1745-1752 


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INTERLOCKING. 


209 


2IO 


INTERLOCKING. 


Fig.  1762 


The  earliest  system  of  Interlocking  employed  and  that  now  in 
most  general  use  is  the  so-called  mechanical  interlocking,  in 
which  the  switches  and  signals  are  manually  operated  by 
means  of  interlocked  levers  connected  with  them  by  iron  or 
steel  pipe  lines  or  by  wire. 

The  fatigue  incident  to  working  mechanical  levers  at  a  busy 
plant  is  often  severe,  so  that  if  the  plant  is  large,  it  is  some- 
times necessary  to  employ  as  many  as  eight  men  on  each  of 
three  shifts  of  eight  hours  each.  Moreover,  under  certain 
conditions  it  is  costly  to  operate  such  a  plant. 

To  overcome  these  and  other  disadvantages  power  inter- 
locking has  been  devised  in  which  the  various  functions  are 
worked  by  air  under  pressure,  by  electricity  or  by  ri  combina- 
tion of  the  two.  With  power,  switches  and  signals  can  be 
worked  at  any  desired  distance  from  tLe  cabin  ;  the  apparatus 
being  so  safeguarded  that  switches  must  actually  be  moved 


and  -securely  locked  in  the  proper  position  befcre  a  signal 
governing  movements  over  them  can  be  cleared.  Each  signal, 
when  cleared,  automatically  locks  the  lever  operating  it  in 
such  manner  as  to  prevent  the  release  of  levers  controlling 
conflicting  signals  and  switches  until  such  signal  has  been 
again  completely  moved  to  the  stop  position,  thus  effectually 
providing  against  the  simultaneous  display  of  two  conflicting 
clear  signals.  There  being  no  moving  parts  between  cabin 
and  switches  and  signals,  wear  of  mechanism,  lost  motion  and 
the  troublesome  effe  ts  of  expansion  and  contraction  of  metal 
connections  are  eliminated.  Much  less  room  is  required  for 
leadout  connections  than  in  a  mechanical  plant,  valuable  space 
thus  being  saved.  Cabins  may  be  much  smaller  and  of  lighter 
design.  The  operation  at  the  machine  requires  so  little  physi- 
cal exertion  that  one  man  in  a  power  operated  plant  can 
perform  work  that  would  require  several  in  a  mechanical  plant. 


ELECTRIC  INTERLOCKING. 


GENERAL      RAILWAY      SIGNAL      COMPANY. 

In  the  General  Railway  Signal  Company's  system  of  elec- 
tric interlocking,  switches  and  signals  are  operated  by 
electric  motors,  the  current  to  actuate  them  being  furnished  by 
a  storage  battery,  usually  charged  from  a  dynamo  driven  by 
an  electric  motor  or  a  gas  engine.  Control  of  the  various  func- 
tions is  effected  through  an  interlocking  machine  such  as  is 
shown  in  Fig.  1762.  The  system  provides  efficient  means  for 
preventing  the  false  operation  of  any  unit  due  to  crosses,  etc., 
and  positively  insures  correspondence  between  the  position  of 
any  unit  and  its  controlling  lever. 

The  interlocking  machine  consists  of  a  group  of  mechan- 
ically interlocked  levers^  to  each  of  which  is  attached  a  suit- 
able electric  circuit  controller  for  the  control  of  its  respective 
function.  During  the  operation  of  such  a  function,  the  lever 


is  automatically  locked  in  a  position  of  incomplete  movement 
until  released  by  an  electro-magnet  on  its  being  energized  by 
a  dynamic  current  which  is  generated  by  the  motor  of  the 
operated  unit.  This  dynamic  current,  or  "indication,"  as  it  is 
called,  is  not  generated  until  a  switch  has  moved  to  a  position 
corresponding  with  tha  lever  and  has  been  properly  locked  in 
that  position,  or  a  signal  arm  has  assumed  the  full  horizon Lil 
position.  The  different  levers  are  interlocked  by  the  means 
of  vertical  locking  similar  in  design  to  the  locking  in  the 
"Standard"  mechanical  machine  but  reduced  in  size,  and  in 
proportion  to  the  number  of  levers,  occupying  but  a  small 
amount  of  floor  space  in  the  tower.  It  is  arranged  to  take  four 
bars  in  each  groove  of  the  locking  plates,  instead  of  the  three 
used  in  the  "Standard"'  machine.  Fig.  1829  shows  the  locking 
as  required  for  the  Hudson  Terminal  installation. 


Fig.  1762.     Installation  of  Unit  Type  Lever   Interlocking  Machine  (Model  2),  Lake  Street  Tower.     Chicago 
Terminal.    C.  &  N.  W.  Ry.,  General  Railway  Signal  Company. 


Figs.  1763-1764 


INTERLOCKING. 


211 


Two  views  of  the  Model  2  interlocking  machine  are  shown 
In  Fig.  1763, — a  front  view  showing  the  locking  and  a  sec- 
tional view  showing  a  switch  lever  with  its  controller,  etc. 
Fig.  1764  shows  front  and  sectional  views  of  portions  of  the  fuse 
and  terminal  board.  The  machine,  in  general,  consists  of  the 
framework,  the  cabinet,  the  terminal  and  liise  board,  the  lock- 
ing and  the  levers  with  their  guides,  magnets  and  circuit  con- 
trollers. 

Th<>    locking   plates   are   furnished    in    tiers   to   a    maximum    of 


and  the  wiring  of  the  machine  proper,  terminate  on  the  bind- 
ing posts  or  fuse  posts  as  the  case  may  be,  the  arrangement 
being  such  that  any  wire  or  other  electrical  part  may  conven- 
iently be  disconnected  for  testing  purposes.  The  connecting 
wires  running  from  the  terminal  board  to  the  various  con- 
trollers are  made  up  in  sets  formed  to  fit,  and  taped  together. 
Terminals  and  fuses  for  each  lever  are  directly  under  it  and 
are  numbered  and  lettered  to  correspond. 

A  view  of  a  switch  lever  assembled  with  its  controller,  safety 


CABINET 


LEVER 
GUIDE 


LAMP    CASE 


LEVER 


IND.  MAGNET — 
SAFETY  MAGNET 


INDICATION 
[SELECTOR 


UUUULJUUU     LJ    LT 


„ LOCKING  BAR 


LOCKING  PLATES 


TAPPET  BAR 


RETAINING   BAR 


Fig.  1/63.     Unit  Lever  Type  Electric  Interlocking  Machine   (Model  2).     General   Railway   Signal   Company. 


three,  the  number  of  tiers  depending  upon  the  complications  in 
the  locking  required.  When  more  than  three  tiers  of  locking 
are  necessary,  a  special  form  of  leg  has  to  be  furnished  to 
accommodate  the  extra  locking  plates. 

The  cabinet  completely  encloses  the  machine  with   the  excep- 
tion  of  the    terminal   board   and   grips   of   the   operating   levers. 


High  Signal  Switch.  Solenoid 

or  Dwarf. 

Model  2A  Dwarf. 

Fig.     1764.      Terminal    Board    Arrangement    Model    2 
Electric    Interlocking    Machine. 

Removable  panels  in  the  front  of  the  cabinet  give  easy  access  to 
to  the  locking,  and  panels  in  the  back  and  glass  covers  on  the 
top  give  access  to  the  levers,  controllers,  etc.  The  glass  cov- 
ers are  generally  locked  or  sealed  to  prevent  unauthorized 
manipulation  or  tampering  with  the  parts. 

A  slate  terminal  board  is  provided  for  making  the  connec- 
tions between  the  interlocking  machine  and  the  external  wires. 
On  this  are  mounted  the  switch  and  signal  bus  bars,  indica- 
tion bus  wires,  polarized  relays,  fuses  and  binding  posts.  The 
various  incoming  wires,  those  from  the  operating  switchboard 


and  indication  magnets  is  shown  in  Figs.  1765-1766.  The  lever, 
which  is  known  as  the  "Unit  Type,"  is  so  designed  that  it  may 
be  removed  with  its  guide  and  indication  magnet,  without  moving 
its  tappet  from  the  normal  position  or  disturbing  adjacent  lev- 
ers in  any  way.  The  lever  is  provided  with  a  cam  slot  U  which 
gives  the  necessary  motion  to  the  tappet  V  to  operate  the  lock- 
ing. The  dotted  circles,  1  to  5  in  the  cam  slot,  indicate  the 
position  of  the  tappet  roller  which  corresponds  with  like  num- 
bered positions  of  contact  block  Z,  the  lever  being  rigidly 
connected  to  the  contact  block  by  the  rod  W.  During  the 
first  part  of  its  travel,  the  lever  moves  the  tappet  bar  through 
one-half  of  its  stroke  by  means  of  the  cam  slot.  During  this 
portion  of  the  movement,  no  change  is  made  in  the  electrical 
connections,  as  the  contact  block  slides  along  the  same  brushes. 
This  preliminary  tappet  movement  locks  all  other  levers  con- 
flicting with  the  new  position  of  the  lever  in.  ofuestion.  The 
middle  part  of  the  travel  of  the  lever  carries  the  contact  block 
from  brushes  at  one  end  of  the  controller  to  the  brushes  at  the 
other  end.  During  this  part  of  the  travel,  the  tappet  bar  re- 
mains stationary  and  the  lever  is  brought  to  stop  by  projec- 
tion J  on  the  latch  L,  having  engaged  with  tooth  Q  on  the 
lever  (see  Fig.  1766),  the  lever  being  held  thus  until  released 
by  indication  magnet  I. 

The  method  by  which  a  switch  lever  is  prevented  from  com- 
pleting its  stroke  until  the  function  controlled  lly  such  lever 
has  assumed  a  position  corresponding  therewith  will  be  under- 
stood by  the  following  changes  which  take  effect  ns  the  lever 
Is  moved  through  its  complete  stroke.  Fig.  1765  shows  the 
lever  normal  and  1766  shows  It  resting  against  the  Indica- 
tion stop  (position  4).  In  passing  from  position  1  to  2.  the 
projection  M  on  lever  D  coming  against  projection  K  on  latch 
L  causes  the  latch  to  assume  the  reverse  position  as  shown 
In  1766,  bringing  projection  J  into  path  of  tooth  Q.  In  moving 
from  position  2  to  3  the  tooth  Q,  coming  in  contact  with  a 
similar  projection  on  the  cam  N,  causes  it  to  revolve  into  the 
horizontal  position,  shown  dotted  in  1766,  thus  forcing  dog  P 
into  the  position  shown  in  1766  and  locking  latch  L  in  its  hori- 
zontal position.  In  moving  from  position  3  to  position  4  the 
cam  N  is  revolved  into  the  position  shown  In  full  lines  in  1766 
and  the  lever  is  stopped  at  position  4  by  the  tooth  Q  coming 


212 


INTERLOCKING. 


Figs.  1765-1766 


against  projection  .T.  Meanwhile  the  contact  block  Z  having 
come  into  contact  with  brushes  X-X  completes  the  battery  cir- 
cuit to  the  motor,  causing  the  switch  to  be  operated  and  locked 
in  position.  The  indication  current  is  then  sent  through  mag- 
net I,  lifting  armature  T  and  causing  plunger  R  to  strike  dog 
P  and  throw  it  out  from  under  latch  L.  The  latch,  being  thus 
released,  drops  to  its  normal  position  shown  in  G,  and  permits 
lever  movement  from  4  to  5,  thus  completing  the  stroke,  which, 
by  lifting  tappet  V,  releases  all  levers  not  conflicting  with  the 
new  position  of  switch.  The  stroke  from  reverse  to  normal 
acts  in  the  same  way.  A  switch  failing  to  complete  its  move- 


generator  voltage  respectively.  Connected  in  series  with  the 
generator  field  and  mounted  on  the  back  of  the  board  is  a 
rheostat  giving  the  variable  resistances  required  to  regulate 
the  charging  current  delivered  from  the  generator  to  the  bat- 
tery. A  "no-load  reverse  current"  circuit  breaker  CB  safe- 
guards the  generator  against  running  as  a  motor  should  the 
generator  voltage  drop  bejow  that  of  the  battery. 

Fig.  1768  gives  the  general  appearance  of  the  operating 
switchboard  with  its  equipment  of  circuit  breaker,  voltmeter, 
ammeter,  ground  detector  lamp  and  switch,  and  indication  red 
light.  Fig.  1770  shows  cross-sections  of  the  circuit  breaker  CB1. 


Figs.    1765-1766.     Diagram    Showing   Operation    of   Unit  Type  Lever  (Model  2  Interlocking  Machine). 

Railway  Signal  Company.    • 


General 


ment  owing  to  some  obstruction  in  the  switch  point,  or  for  any 
other  cause,  may  be  restored  to  its  original  position,  and  its 
lever  operated  back  and  forth,  thus  frequently  dislodging  the 
obstruction,  thereby  preventing  a  tie-up  and  incidental  deten- 
tions. The  lever,  however,  can  neither  be  placed  fully  normal 
nor  fully  reversed  without  the  proper  indication  being  re- 
ceived, showing  that  the  switch  has  been  locked  in  the  position 
corresponding  with  that  of  the  lever. 

Levers  for  signals  operate  in  the  same  manner  with  the 
exception  that  the  lever  Is  allowed  to  pass  to  the  full  reverse 
position  5,  without  an  indication  being  received,  since  an  un- 
safe condition  does  not  result  if  the  signal  for  any  reason  fails 
to  clear. 

Fig.  1767  shows  diagrammatically  the  apparatus  required  at 
a  typical  interlocking  plant,  and  the  circuits  for  same.  A 
generator  with  suitable  driving  power  and  storage  battery  of 
proper  capacity  are  required  to  supply  the  energy  necessary 
for  the  operation  of  the  plant.  The  switchboards  shown  are 
in  accordance  with  .the  G.  R.  S.  Go's,  latest  practice,  the  oper- 
ating board  being  equipped  with  an  improved  type  of  cross- 
protection  circuit  breaker.  The  power  board  is  used  to  regu- 
late and  safeguard  the  circuit  from  the  generator  to  the  bat- 
tery and  from  the  battery  to  the  operating  board,  and  the 
operating  board  to  distribute  and  protect  the  circuits  to  the 
interlocking  machine  and  the  apparatus. 

The  power  board  (Fig.  1768)  is  arranged  to  serve  the  inter- 
locker  from  the  generator  direct  or  from  the  battery  during 
either  the  period  of  charging  or  discharge.  An  ammeter  and 
voltmeter  controlled  by  suitable  switches  are  provided  to 
record  the  charging  or  discharge  current  and  the  battery  or 


The  circuit  breaker  CB1,  which  operates  on  the  closed  cir- 
cuit principle,  is  so  controlled  that  ^t  will  be  opened  by  the 
improper  application  of  current  to  any  unit,  thereby  cutting 
off  all  operating  current  from  the  interlocking  plant.  It, 
furthermore,  is  designed  to  prevent  the  restoration  of  power 
to  the  plant  until  such  time  as  the  cross  has  been  removed. 
All  contacting  parts  of  the  circuit  breaker  are  under  a  sealed 
case  with  only  the  restoring  handle  projecting  out  within  reach 
of  the  leverman.  In  case  the  circuit  breaker  opens,  the  oper- 
ator first  attempts  to  eliminate  the  cause  of  the  trouble,  then, 
grasping  the  restoring  handle,  raises  it  to  its  upper  stop,  at 
once  restoring  it  to  its  normal  position.  If  the  trouble  has  not 
been  remedied,  the  circuit  breaker  immediately  opens  again. 
Should  the  operator  attempt  to  plug  the  circuit  breaker  or  to 
hold  it  in,  he  will  accomplish  nothing  more  than  to  keep  the 
plant  inoperative  until  the  proper  correction  has  been  applied. 

The  coils  of  the  circuit  breaker  CB1  are  controlled  in  series 
through  the  points  of  the  polarized  circuit  breakers  or  relayn 
I-I1,  H2,  H3  and  II4,  which  are  mounted  upon  the  terminal 
board  of  the  interlocking  machine.  Referring  to  Fig.  1767,  it 
will  be  seen  that  each  function  is  protected  by  one  of  these' 
relays,  the  current  which  passes  through  its  coils  during  t 
proper  operation  of  such  a  function  always  taking  the  sam«' 
direction.  A  current  from  an  unauthorized  source  would  have 
two  paths  to  follow,  one  tending  to  operate  the  function  anc 
the  other  through  the  polarized  relay  Hx  in  the  direction  tend'1 
ing  to  reverse  its  armature,  thereby  opening  the  control  cin 
cult  of  CB1  on  the  operating  board.  Circuit  breaker  CB1,  imi 
mediately  opening,  cuts  off  all  power  from  the  plant  and  pre' 
vents  the  restoration  of  power  until  the  removal  of  the  cross- 


Fig.  1767 


INTERLOCKING. 


213 


fls, 


214 


INTERLOCKING. 


Figs.  1768-1769 


the  operator  being  notified  of  the  existent  trouble  by  the  red 
lamp  which  is  lighted  through  the  closing  of  circuit  breaker 
contacts,  Y-Y  and  Y'-Y1.  The  control  circuit  of  the  circuit 
breaker  coils  also  breaks  through  the  point  of  polarized  relay 
H,  located  on  the  operating  board,  this  relay  acting  as  a  cir- 
cuit breaker  to  prevent  the  blowing  of  the  main  fuses  on  the 
power  switchboard  in  case  of  an  accidental  short  circuit  be- 
tween the  positive  bus  and  the  indication  bus  on  the  interlock- 
ing machine. 

It  will  be  noticed  that  both  the  positive  and  negative  con- 
nections between  the  power  board  and  interlocking  plant  are 
broken  through  the  blades  of  the  circuit  breaker.  This  per- 
mits full  measure  of  protection  in  case  it  is  desired  to  sec- 
tionalize  the  interlocking  plant  so  that  the  operation  of  only 


Fig.  1768.     Operating  Switch  Board  (Improved  Circuit 
Breaker).      General    Railway   Signal    Company. 


that  part  of  the  plant  immediately  concerned  will  be  inter- 
fered with  in  case  of  trouble. 

The  ground  detector  switch  X3,  by  lighting  the  white  lamp, 
gives  indication  of  a  ground  on  the  positive  or  negative  wires 
on  being  thrown  to  the  left  or  right  contact  respectively. 

The  switchboard  if  desired  will  be  provided  with  resistance 
units  which  are  arranged  to  permit  the  flow  of  sufficient  cur- 
rent to  hold  such  signals  in  a  clear  position  as  were  so  dis- 
played when  the  circuit  breaker  opened.  Due  to  the  resistances, 
sufficient  potential  will  not  exist  at  the  bus  bars,  with  the  cir- 
cuit breaker  CB1  open,  to  permit  the  operation  of  any  function. 

In  Fig.  1767  levers  1  to  4  inclusive  are  shown  with  suitable 
circuits  for  the  control  of  G.  R.  S.  Co.  Model  2A  distant  and 
home  signals,  solenoid  dwarf  signal  and  Model  2  switch  move- 
ment. 

The  switch  movement  is  controlled  by  two  wires  in  addition 
to  the  main  common  wire,  the  current  generated  by  the  switch 
motor  itself  being  transmitted  through  the  common  wire  and 
either  one  of  the  two  control  wires.  In  one  position  of  the 
lever,  one  of  these  wires  is  the  control  and  the  other  is  the 
indication  wire,  while  in  the  other  position  these  conditions 
are  reversed.  One  of  these  wires  is  connected  to  the  positive 
terminal  of  the  battery  through  the  coils  of  the  indication  se- 


lector and  those  of  safety  magnet  S4  to  the  switch  bus  bar, 
and  the  other  wire  is  connected  to  common  through  the  con- 
tacts on  the  indication  selector,  the  colls  of  indication  magnet 
I4,  coils  of  the  polarized  relay  H4,  the  indication  bus  wire, 
post  7  of  the  operating  board,  coils  of  polarized  relay  H  to 
post  3  of  the  operating  board ;  when  the  lever  is  reversed, 
these  connections  are  reversed  also. 

Indication  selector  RC-NC  (Fig.  1767)  is  arranged  In  such 
a  manner  that  energy  flowing  through  the  operating  wires  at- 
tracts the  armature  and  closes  the  contacts  for  the  reverse  in- 
dication when  the  reverse  operating  wire  is  energized  and  for 
the  normal  indication  when  the  corresponding  operating  wire  is 
energized. 

The  safety  magnet  S4  is  placed  beneath  indication  mag- 
net I4,  the  indication  armature  resting  normally  on  the  pole 
pieces  of  the  safety  magnet.  By  referring  to  circuits,  Fig.  1767. 
it  will  be  seen  that  a  cross  between  the  two  control  wires  could 
in  no  case  cause  the  current  flowing  through  the  indication 
coils  to  exceed  that  flowing  through  the  safety  magnet ;  and 
since  the  armature  rests  upon  the  safety  magnet  and  is  a 
quarter  of  an  inch  away  from  the  indication  magnet,  an  in- 
dication cannot  be  effected.  The  safety  coils  being  connected 
in  series  with  the  control  circuit,  a  break  in  any  of  the  wires 
concerned  would  cut  off  current  from  the  function. 

The  circuit  controller  P  or  pole  changer  is  placed  at  the 
switch,  and  is  operated  automatically  through  the  medium 


Fig.  1/69.     Circuit  for  Model  "2 A."  Semi-Automatic  Inter- 
locking Signal.      (Dynamic  Indication.) 


of  the  mechanical  movement  I  (Fig.  1780),  by  the  lock 
plunger  in  the  last  part  of  its  stroke  after  it  has  passed 
through  the"  lock  rod  and  locked  the  switch.  The  arrange 
ment  of  this  mechanical  movement  is  such  that  two  pins 
mounted  upon  the  lock  rod  M  shift  the  point  of  fulcrum  in  the 
mechanical  pole  changer  movement,  so  that,  with  the  same 
movement  of  the  lock  plunger,  the  pole  changer  contacts  are 
thrown  first  in  one  direction  and  then  in  the  other  direction, 
their  position  corresponding  to  the  n.osition  which  the  switch 
points  have  assumed.  The  electrical  connections  are  such 
that  in  one  position  of  the  pole  changer,  terminal  B  of  the 
armature  is  connected  to  the  control  wire  and  terminal  B4 
to  the  field  coils,  while  in  the  other  position,  terminal  B1 
is  connected  to  the  other  control  wire,  and  terminal  B  to 
the  field  coils.  The  operation  of  the  pole  changer  accom 
plished  three  objects  : 

(1)  To  cut  current  off  from  the  motor;  (2)  to  reverse  the 
armature  connections;  (3)  to  complete  the  indication  circuit, 
at  the  same  time  leaving  the  proper  circuits  set  up  for  the  nest 
movement  of  the  switch  machine. 

The   pole   changer,   furthermore,    is   under   the   control   of   two 
sets  of  magnets,  so  that,  should  the  switch  fail  to  complete  its 
movement    and    give    the   necessary    indication,    the    position    of 
the    controlling    lever    may    be    shifted,    and    through    the    ener- 
gizing of  one  or  the  other  of  the  sets  of  pole  changer  magnets 
cause    the    pole    changer    to    assume    a    position    corresponding 
to    that   taken    by   the    lever.      This    accomplishes    the   object   of 
setting   up   the   proper   circuit   for   the   operation   of   the   switch 
movement   in   any   desired   direction.     It   will   be   seen   that   thlgi 
feature    places    the    switch    so    under    the    control    of   the    lever- 
man    that,    should    the    points    be   blocked    with    snow,    etc.,    the 
operator    may     work     the    controlling    lever     back     and     forth, 
frequently    dislodging    the    obstruction,    thereby    permitting    the* 
desired    movement    of    the    switch    to    be    completed. 

Circuit  breaker  CB4  (Fig.  1767),  shown  in  the  diagram,  iss 
operated  automatically  by  the.  switch  movement  and  cuts  offl 
current  from  the  magnets  M-M  when  the  switch  is  normal,  andJ 
from  M4-M4  when  the  switch  is  reversed,  this  taking  place  only 
when  switch  is  home  and  securely  locked  in  position. 


Figs.  1770-1711 


INTERLOCKING. 


215 


In  the  diagram  (Pig.  1767),  all  functions  are  shown  in  the 
normal  position.  By  reversing  lever  4,  the  reverse  operating 
wire  is  placed  in  connection  with  the  battery,  causing  current 
to  flow  from  battery  through  the  safety  and  control  devices 
on  the  power  and  operating  boards  to  the  switch  bus  bar,  fuse, 
safety  magnet  S4,  indication  selector  coil  RC,  circuit  con- 
troller contacts  15-16,  the  reverse  control  wire,  pole  changer 
contacts  26-27,  switch  motor  armature  AJ,  pole  changer  con- 
tacts 2S-29,  field  coils  F4,  to  main  common  and  back  to  the 


control  wire  for  the  other  operation),  pole  changer  contacts 
30-31  to  the  terminal  B4  of  the  armature,  thereby  energizing 
indication  magnet  I4  and  tripping  the  indication  mechanism 
as  explained  in  the  operation  of  the  lever  (pages  211-212). 

Placing  lever  4  in  the  normal  position  again  connects  the 
normal  control  wire  with  battery,  causing  current  to  flow 
through  safety  magnet  S4,  coil  NC  of  indication  selectors,  con- 
tacts 17-18  of  switch  circuit  controller,  normal  control  wire, 
pole  changer  contacts  30-31  to  armature  terminal  B4,  through 


POLE     PIECES 


ARMATURE 


COVER 

SHIELD 
RESTORING     HANDLE 


CIRCUIT     BREAKER 
OE-ENERGIZED 


CIRCUIT     BREAKER 
BEING     RESTORED 

PARTS      SIMILARLY      LETTERED       MAKE       CONTACT      WITH      EACH      OTHER 


CIRCUIT     BREAKER 
IN     OPERATING     POSITION 


ig.    1/70.     Sectional   View   of   Operating   Switch   Board  Circuit    Breaker.      General    Railway    Signal    Company. 


negative  side  of  the  battery.  The  motor  operates  the  switch 
mechanism,  and,  when  the  switch  has  completed  its  move- 
ment, the  lock  plunger  changes  the  pole  changer  from  con- 
tacts 26-27  to  contacts  30-31  and  from  contacts  28-29  to 
contacts  32-33,  thereby  disconnecting  the  reverse  control  wire 
from  the  circuit,  connecting  in  the  reverse  indication  wire 
and  reversing  the  armature's  relation  with  its  fields. 

An     electric     motor     when     driven     by     a     current     tends     to 
develop    an    electro-motive    force    in.  opposition    to    the    driving 


the  armature  in  the  opposite  direction  to  that  taken  in  the 
reverse  operation  of  the  switch,  thence  through  the  fields  to 
common.  The  armature  rotation  is  consequently  reversed  and 
the  switch  points  move  back  to  their  normal  position.  At  the 
end  of  the  movement,  the  pole  changer  P  is  shifted  back  to 
the  position  shown  in  the  diagram  and  the  indication  current 
is  generated  as  before,  leaving  the  terminal  B4  and  returning 
to  the  terminal  B  through  the  normal  indication  wire. 
Fig.  1771  shows  diagrammatically  the  cycle  of  operation  of  a 


NORMAL     CONDITION    OF    REST  REVERSE     OPERATION  REVERSE     INDICATION  NORMAL     OPERATION  NORMAL     INDICATION 

Fig.  1771.     Operation  of  Electric  Switch  Machine.      General    Railway    Signal    Company. 


electro-motive  force,  and,  after  the  current  is  cut  off,  the 
armature  continues  to  rotate  from  acquired  momentum  and 
continues  to  develop  this  electro-motive  force.  The  new  con- 
nections made  by  the  pole  changer  as  above  described  are 
such  that  the  electro-motive  force  thus  developed  sends  a 
current  from  the  armature  at  terminal  B,  which  passes  through 
the  field  coils  in  the  same  direction  as  the  driving  current 
flowed,  thus  maintaining  their  magnetization,  through  the 
main  common  to  post  3  on  operating  board,  coil  of  polarized 
relay  H,  post  7  on  operating  board,  indication  bus  wire,  coil 
of  polarized  relay  H4  on  interlocking  machine,  indication  mag- 
net I4,  contacts  of  indication  selector  23-25,  contacts  19-20 
of  controller,  re\erse  indication  wire  (which  is  the  normal 


switch  function,  the  wires  carrying  current  being  shown  heavy, 
and  the  direction  of  current  by  the  arrow  heads. 

When  it  is  desired  that  two  switches  be  operated  together, 
for  instance  both  ends  of  a  cross-over,  a  special  short  lever  Is 
used  for  one  and  a  standard  lever  for  the  other,  these  two 
levers  being  placed  next  to  each  other  in  the  machine  and 
connected  by  a  plate,  so  that  they  move  together. 

Home  signal  No.  2  is  controlled  by  a  110-volt,  non-automatic 
Model  2A  mechanism,  dynamic  indication.  Lever  2,  on  being 
reversed,  causes  current  to  flow  from  the  signal  bus  bar  through 
lever  contacts  5-6,  the  control  wire,  signal  armature  and  field, 
thence  through  normal  contact  on  switchbox  to  main  com- 
mon, thereby  clearing  the  signal.  At  the  proceed  position 


2l6 


INTERLOCKING. 


Figs.  1772-1773 


high-resistance  retaining  coils  are  cut  in  series  with  the  oper- 
ating coils,  thus  reducing  the  hold  clear  current  to  a  mini- 
mum. The  reverse  indication  is  not  required,  as  it  is  not  an 
unsafe  condition  if  the  signal  fails  to  go  to  the  proceed 
position. 

When  the  lever  is  placed   at  the  normal   indication  point,  the 


switchboard,  coil  of  polarized  relay  H,  post  7  of  the  operating 
board,  indication  bus  wire,  polarized  relay  H2,  signal  con- 
troller contacts  7-8,  indication  magnet  I2  and  signal  control 
wire,  and  back  to  the  motor.  Due  to  its  momentum,  the  motor 
immediately  generates  an  E.  M.  P.,  forcing  a  current  through 
the  closed  circuits  described  above,  tripping  the  indication 


OPERATING 


HOLDING 


INDICATING 


NORMAL 

Fig.  17/2.     Operation  of  Model  "2A"  Signal.     Dynamic  Indication,     Non-Automatic    Control.       Genera'     Railway 

Signal  Company. 


circuit  is  broken  at  signal  controller  contacts  5-6,  and  by  the 
closing  of  contacts  7-8  the  control  wire  is  connected  with  the 
indication  magnet,  and  through  the  polarized  relay  H2  to  the 
indication  bus  wire.  The  signal,  in  returning  to  the  normal  posi- 


mechanism  on  the  controlling  lever,  thereby  allowing  it  to  be 
restored  to  the  full  normal  position.  The  building  up  of  the 
E.  M.  F.  checks  the  momentum  of  the  armature  and  brings 
the  signal  mechanism  to  rest  without  shock. 


A-  Operating  Coils 
B-  Holding  Coils 

Common 


NORMAL  OPERATING 

Fig-   1/73-     Operation   of  Solenoid  Dwarf  Signal. 


HOLDING  INDICATING 

General    Railway    Signal    Company. 


tion,  drives  the  armature  in  the  direction  opposite  to  that  taken 
while  clearing,  and,  when  a  few  degrees  from  the  normal 
position,  through  the  closing  of  a  contact  on  the  signal  circuit 
breaker,  the  motor  is  placed  on  the  following  closed  circuit : 
From  the  motor,  through  main  common,  post  3  of  operating 


When  it  is  desired  to  have  the  signal  controlled  semi-auto- 
matically,  the  mechanism  differs  from  the  other  in  that  the  first 
part  of  the  movement  does  not  affect  the  position  of  the  blade, 
but  puts  under  tension  set  of  coil  springs  which  are  strong 
enough  on  the  normal  movement  to  rotate  the  motor  backward 


Figs.  1774-1778 


INTERLOCKING. 


217 


with  sufficient  speed  to  generate  current  for  tripping  the  indica- 
tion mechanism  on  the  lever.  Should  the  track  circuit  be 
occupied,  the  controlling  lever  being  reversed,  the  mechanism 
will  be  held  with  the  springs  under  tension  just  as  this  type 
of  mechanism  is  held  at  any  of  the  proceed  positions  of  the 
blade.  Should  the  track  circuit,  however,  be  unoccupied,  the 
signal  mechanism  will  continue  its  movement,  carrying  the 
blade  to  the  proper  proceed  position,  its  operation  from  this 
point  on  being  similar  to  the  regular  Model  2A  mechanism, 


The  distant  signal  is  operated  and  the  indication  current 
generated  in  the  same'  manner  as  described  for  home  signal 
No.  2,  the  operation  being  controlled  by  lever  1  and  circuit 
controller  on  the  home  signal  mechanism. 

Dwarf  signals  may  be  operated  by  a  Model  2A  mechanism, 
having  either  non-automatic  or  semi-automatic  control,  the 
same  as  the  high  signals  just  described,  or  the  dwarf  may  be  of 
the  solenoid  type,  such  as  is  controlled  by  lever  3  in  Fig.  1767. 

The    solenoid    dwarf    (Fig.    1767)     is    provided    with    a    sole- 


Figs.    1774-1775.     Model  2.   Electric   Switch  and   Lock   Movement.     General   Railway  Signal   Company. 


Names  of  Parts,  Electric   Switch  and   Lock  Movement;   Figs.   1774-1775. 

A    Motor  H     Lock  Movement  N    Front  Rod 

B     Connecting   Shaft  I      Pole  Changer  Movement  O     Tie  Plate 

C     Pole  Changer  J      Detector  Bar  Operating  Mechan-       P     Throw  Rod 

D     Cam  Crank  ism  R    Lock  Crank 


E    Driving  Pin 

F     Gears  and  Frame 

G    Driving  Rod 


K    Long  Ties 

L     Outline  of  Cover 

M    Lock  Rod 


S    Lock  Link 

T    Detector  Bar  Driving  Link 

W  Pole  Changer  Rod 


Fig.  1776. 


Lock  Plunger;  Locks  Both  Lock  and  Throw 
Rods. 


Fig.    1777.     Link    S,   Figs.    1774-1775. 


IS) 


Fig.   1778.     Throw  Rod,  with  Tappet  for  Lock  Plunger.     See  H,  Fig.   1774- 


previously  described.  It  will  be  noticed  that  the  first  40-deg. 
movement  of  the  mechanism  is  always  under  the  control  of  the 
operating  lever,  its  circuit  not  being  broken  through  the  track 
relay  as  is  that  which  controls  the  actual  movement  of  the 
semaphore  arm,  consequently  a  dynamic  indication  may  be  ob- 
tained any  time  the  lever  is  restored  to  the  normal  position, 
regardless  of  train  movement.  The  circuit  breaker  of  the 
signal  is  so  wired  that,  a  train  having  accepted  and  put 
the  signal  to  block,  it  will  be  necessary  to  place  the  con- 
trolling lever  full  normal  and  reverse  it  again  before  a  second 
clearing  of  tii~  signal  may  be  accomplished. 


noid  having  two  sets  of  windings,  working  coils  of  low 
ohmic  resistance  and  retaining  coils  of  high  resistance.  As 
it  is  impracticable  to  secure  a  dynamic  indication  from  a 
dwarf  of  the  solenoid  type,  battery  indication  is  required.  The 
signal,  therefore,  needs  for  its  operation  an  indication  wire 
in  addition  to  the  usual  control  wire.  Lever  3,  on  being  re- 
versed, causes  current  to  flow  from  the  signal  bus  bar  through 
the  dwarf  lever  contacts  9-10,  the  control  wire  and  the  working 
coils  W-W  of  the  dwarf  to  common.  Upon  the  signal  arm 
assuming  the  proceed  position,  a  circuit  breaker  on  the  signal 
proper  cuts  the  retaining  coils  R-R  in  series  with  the  operating 


2l8 


INTERLOCKING. 


Figs.  1779-1788 


Fig.    1779.     Driving   Rod   G.      Model  2  Switch. 

a 


Fig.     1781.      Commuta- 
tor V.     Fig.    1787. 
Model  2  Switch. 


Fig.   1780.     Pole  Changer  Movement  I.     Model  2  Switch. 


Figs.    1782-1786.     Friction    Clutch.     Model    2    Switch. 


f 

o 

_c==L_ 

0 

G 

\  —  i—  _( 

Fig.    1787.     Pole  Changer.     Model  2   Switch. 


o 
o      o 


o      o 
o      o 


\ 


Fig.    1788.      Tie    Plate, 

with  Slot  for  Gear 

Wheel   O.    Model 

2   Switch. 


Names  of  Parts,  Pole  Changer;  Fig.   1787. 

A     Case  E     Operating  Kod 

B     Solenoids  F    Snap  Spring 

C     Contact  Springs  G    Contact  Block 

D     Contact  Block  H     Contact  Block 


I     Binding  Posts 
K  ,  Armatures 
L    Shaft 
V     Commutator 


Figs.  1789-1793 


INTERLOCKING. 


219 


coils,  thereby  reducing  the  holding  current  to  the  lowest  point 
at  which  the  signal  blade  can,  with  certainty,  be  held  in  the 
clear  position.  As  in  the  case  of  the  high  signal  levers,  the 
lever  controlling  the  solenoid  dwarf  is  designed  to  pass  to  the 
full  reverse  position  without  receiving  an  indication.  When 
the  lever  3  is  pushed  back  to  the  normal  indication  point,  the 
•circuit  through  the  retaining  coils  is  broken  and  the  signal 
arm  returns  to  the  stop  position.  A  circuit  controller  on  the 
signal,  which  is  closed  only  at  full  normal  position,  allows 
current  to  flow  from  the  signal  bus  bar  through  the  indication 
magnet,  lever  contacts  13-14,  indication  wire,  to  the  circuit  con- 


plunger,  this  movement  being  a  completion  of  the  stroke  locking 
the  switch  in  either  its  normal  or  reverse  position.  By  the 
pole  changer  movement  (Fig.  1780)  the  pole  changer  C  Is 
caused  to  throw  In  one  direction  when  the  switch  has  reached 
its  normal  position  and  in  the  other  when  the  switch  has 
reached  its  reversed  position,  such  movement  of  the  pole 
changer  opening  the  operating  circuit  and  closing  the  circuit 
for  the  Indication.  As  explained  in  the  preceding  paragraph, 
the  pole  changer  is  under  the  control  of  the  lever,  excepting 
when  the  switch  is  locked  in  either  normal  or  reversed  posi- 
tion, through  the  medium  of  the  pole  changer  magnets  M-M  and 


Fig.  1790.     Switch  and  Lock  Movement  Cover  L. 


Fig.  1791.     Motor  Brush  Holder.  Fig.     1792.      Connecting    Shaft    B. 

Figs.  1789-1792.     Parts  of  Model  2  Electric  Switch  and  Lock  Movement,  Figs. 
1774-1775.     General  Railway   Signal   Company. 


troller  in  question  and  to  common,  thereby  tripping  the  indica- 
tion mechanism  and  allowing  the  lover  to  be  placed  full  normal. 
Contacts  13-14  are  designed  to  make  contact  only  at  the  indica- 
tion point  so  as  to  prevent  unnecessary  waste  of  current  or 
heating  of  the  coils.  Cross  protection  is  held  through  stub 
normal  contacts  11-12. 

The  Model  2  type  of  electric  switch  and  lock  movement,  when 
•connected  to  a  single  switch,  is  shown  in  Figs.  1774-1775.  It 
consists  of  the  following  essential  parts :  motor,  pole-changer, 
gear  frame  an  '  lock  movement.  The  gear  frame  is  arranged 
to  simultaneously  raise  the  detector  bar  and  withdraw  the 
lock  plunger.  After  the  unlocking  is  fully  accomplished,  the 
switch  points  are  thrown,  this  movement  being  followed  by  the 
simultaneous  lowering  of  the  detector  bar  and  the  locking  of 
the  switch  in  its  new  position.  The  gear  frame  is  designed 
to  further  allow  the  switch  motor  to  continue  on  several  revolu- 
tions, thereby  generating  the  indication  current,  which  at  the 
same  time  checks  the  speed  of  the  motor  and  brings  it  to  rest 
without  shock.  The  movement  is  provided  with  a  friction 
clutch  to  relieve  the  entire  switch  mechanism  of  injurious 
strain,  should  the  movement  of  the  switch  be  obstructed  or 
should  the  indication  current,  for  any  reason,  fail  to  be  gen- 
erated. Movement  is  imparted  to  the  various  switch  parts 
by  the  motor  through  a  train  of  gears,  the  pin  E  on  main 
gear  being  directly  connected  with  the  lock  movement  by  the 
rod  G  and  to  the  switch  points  by  engagement  with  the  cam 
crank  D.  It  is  through  the  medium  of  the  lock  movement  II 
that  the  lock  plunger,  detector  bar  and  pole  changer  are  op- 
iated. Simultaneous  movement  is  transmitted  from  the  crank 
R  to  the  lock  plunger  through  link  S,  and  to  the  detector 
bar  through  link  T.  It  will  be  seen  that  a  train  occupying  the 
track,  in  preventing  the  initial  movement  of  the  detector  bar, 
would  make  impossible  the  withdrawal  of  the  lock  plunger  and 
the  consequent  movement  of  the  switch  points.  Motion  is  Im- 
parted to  the  pole  changer  C  through  the  medium  of  the  pole 
changer  movement  I  by  the  last  %-in.  movement  of  the  lock 


M4-M4.  The  circuit  breaker  CB4  (Fig.  1767  and  1768)  is  ar- 
ranged to  cut  current  off  from  these  magnets  whenever  the 
switch  is  in  its  full  normal  or  full  reverse  position.  Figs. 
1774-1775  show  gear  frame  together  with  the  stock  rails  se- 
curely bolted  and  braced  to  a  tie  plate  O,  by  this  means  rigidly 


Fig.    1793.      Installation   of    Model    2    Switch    Machine, 
Mayfair,   111.,  C.  &  N.  W.   Ry. 

maintaining  all  of  their  parts  in   their  proper  relation   to   each 
other.      The    lock,    front    and    throw    rods    are    shown    in    Figs. 
1774-1775  at  M,  N  and  P,  respectively. 
Fig.    1796    illustrates    an    arrangement    for    throwing    one    de- 


220 


INTERLOCKING. 


Figs.  1794-1796 


Fig.     1794.       Assembly     of     Model 

"2A"  Interlocking  Bridge  or 

Bracket  Signal. 


u 


Fig.     1795.       Assembly    of     Model 

"2A"    Interlocking    Ground 

Signal. 


Figs.  1797-1802 


INTERLOCKING. 


221 


tector    bar    from    either    of    two    switch    movements.      The    de-  and   that   of  the   lever   at   B   is   connected   to   the   detector   bar. 

vice   consists    of   a    floating    lever   at    B,    centrally    connected   to  If  the   upper  end  of  the   lever  at  B  be  moved  to  the  left,   the 

a    pivoted    lever    at    A.     The   upper   extremity    of    each    lever   is  lever   will   move   about   its   center   as   an   axis   and   the   bar   will 

connected    to    the    lock    crank    of    its    respective    switch    move-  be   moved.      In  this   case   the   center  of   the   lever   is   held   sta- 

ment.      The   lovrsr  end  of  the  lever  at   A   is   pivoted  as  shown,  tionary  by   the  rod  and   the   lever  at  A.      If  the  lever  at  A  be 


O 


o  o 


J* cb_ 


f- 1  ^OD — CD'- 

Fig.  1800.     Locking  Bar — Model  4  Switch  Machine. 

a 


Fig.  1801.    Throw  Rod — Model  4  Switch  Machine. 


Fig-  1/97-     Outline  and  Dimensions  of  Model  4  Switcb       Fig.    1802.      Installation    of    Model   4    Switch    Machine, 
Machine.  Chicago  Terminal.     C.  &  N.  W.  Ry. 


-2f4  W 


-s-f 


—  1 

—  1 

i 

—  1 

—  1 

•o 

—  1 

_l 

: 

1 

1— 

1  

m 


tf 


;TIE-10"X10"XU'-0! 
FIE  N0.1. 

TIE-10"X10"X14'-0'.' 
TIE  NO.  2 
TIE-IO'XIO'XU'-O1: 


10"- 


SECTION       SECTION 
M-«  X-Y 


TIE  NO.  2 
—  H'-O  — 


— s'-si" H^r-ii- 


TIE  NO  3. 

FOR  MOVABLE  POINT  FROG. 


FOR  SINGLE  SWITCH 


A  '  C  +  HEIGTH  OF  MACHINE  (10  |  )  -  HEISTH  OF  RAIL . 

1  -  C  -f-  HEIGTH  OF  MACHINE  (  S  f")  -  HEICTH  OF  RAIL. 

C^  DISTANCE  BETWEEN  TOP  OF  RAIL  AND  TOP  OF  MACHINE. 

D>A+  i 

r .  B  +  J". 


Figs.  1798-1799.     Framing  for  Model  4  Switch  Machine.       General  Railway  Signal   Company. 


222 


INTERLOCKING. 


Figs.  1803-1811 


GO  OJ  O  O 


Figs.   1803-1806.     Model  4-A  Switch  Machine.     Assembly  Single  Switch  or  Movable  Point  Frog.     General  Rail- 
way Signal  Company. 


Top  View.  Section.  Bottom  View. 

Figs.  1807-1809.    Main  Cam  Gear,  Model  4  Switch  Machine.    General  Railway  Signal  Company. 


Supplemental  Cover  Closed.  Supplemental  Cover  Open. 

Figs.   1810-1811.     Universal  Model  5,  Form  A  Switch   Box.     General   Railway  Signal   Company. 


Figs.  1812-1813 


INTERLOCKING. 


223 


Fig.  1812.     Installation  Model  4  Switch  Machine.      New    York    Central    Electric    Zone. 


moved  to  the  right,  it  will  move  the  connecting  rod,  which 
will  transmit  motion  to  the  lever  at  B.  This  lever  will  move 
to  the  right  about  its  upper  end  as  an  axis  and  the  bar  will 
be  thrown.  These  levers  are  so  proportioned  that  in  either  of 
the  above  cases  the  bar  would  be  moved  through  half  its  full 
stroke — that  is,  to  the  center  and  back.  If  both  switches 
should  be  moved  at  once,  the  bar  would  move  through  its  full 


Fig.    1813.     Installation    Model  4  Switch   Machine,  and 

Model  2-A  Dwarf  Signals.     Chicago  Terminal. 

C.  &  N.  W.  Ry. 


stroke  and  back,  since  the  upper  end  of  the  lever  at  B  would 
be  moved  to  the  left  at  the  same  time  that  its  center  was  moved 
to  the  right. 

The  Model  4  switch  machine  shown  in  Figs.  1797-1806 
inclusive,  is  designed  so  that  it  is  suitable  for  installation 
where  clearances  are  limited  and  where  it  is  desired  to  have 
all  operating  parts  within  one  case.  All  parts  are  especially 
designed  for  being  accessible,  and  the  case  to  afford  complete 
protection  against  the  weather  and  to  be  absolutely  dust- 
proof.  The  case,  which  is  substantially  constructed  of  cast 
iron,  forms  a  base  plate  for  the  mechanism  and  is  bolted 
through  the  tie  plate  to  the  head  block  and  the  ;next  tie  back 
(Figs.  1798-1799).  The  mechanism  can  be  used  as  either  right 
or  left  hand,  without  change,  as  it  makes  no  difference  to  which 
side  the  lock  and  throw  rods  are  connected.  One  or  two 
adjustable  lock  rods  can  be  used  which  permit  the  use  of  the 
machine  for  the  operation  of  double  slip  or  movable  point 
frogs. 

The  motor  is  of  the  four-pole  type,  power  being  applied  to 
the  switch  points  through  a  train  of  gears  and  the  cam  move- 
ment on  the  main  gear,  the  whole  being  protected  as  In  the 
Model  2  switch  machine  by  a  friction  clutch  designed  with 
large  surfaces  and  lined  with  fiber.  Where  it  is  desired  to 
operate  the  switch  other  than  electrically,  by  inserting  a  crank 
into  a  hole  in  the  end  of  the  armature  shaft  it  is  possible  to 
turn  the  machine  through  the  whole  or  any  part  of  its  move- 
ment. An  internal  switch  box  can  be  provided,  which  is  so 
designed  as  to  permit  the  closing  of  its  contacts  only  when 
the  switch  points  have  been  moved  to  and  locked  in  their 
proper  position.  To  insure  that,  on  the  completion  of  any 
movement,  both  switch  points  and  machine  lie  in  their  proper 
relative  position,  the  lock  rod  Is  provided  with  separate  dogs  for 
locking  the  lock  bar  in  the  normal  and  reverse  positions,  re- 
spectively, these  dogs  having  such  relative  position  to  the  lock 
rod  that  the  normal  dog  may  not  enter  the  notch  in  the  lock 
bar  when  the  switch  is  in  the  reverse  position  and  vice  versa. 
Fig.  1803  shows  view  of  the  motor,  friction  clutch,  main  gear, 
pole  changer  and  mechanical  circuit  controller  assembled  within 
the  case.  Fig.  1800  shows  the  locking  bar,  Fig.  1801  the  throw 
rod,  and  Figs.  1807-1809  top,  sectional,  and  bottom  views, 
respectively,  of  the  main  cam  gear. 

The  intermittent  movement  in  the  locking  bar  is  accomplished 
by  the  rollers  O-O  on  the  locking  bar  (Fig.  1800)  engaging  with 
the  cam  U  on  the  upper  side  of  the  main  gear  (Fig.  1807).  The 


224 


INTERLOCKING. 


Figs.  1814-1817 


switch  points  are  thrown  by  the  roller  V  on  the  lower  sido 
of  the  main  cam  gear  (Fig.  1809)  engaging  a  jaw  in  the  throw 
rod  (Fig.  1801). 

The  cycle  of  operation  of  the  Model  4  switch  machine  is  es- 
sentially the  same  as  in  the  Model  2,  with  the  exception  that  a 
90-deg.  free  run  of  the  main  cam  gear  is  added  at  the  start 


The  motor  is  directly  connected  to  the  semaphore  shaft 
through  low  reduction  gearing,  so  that  the  armature  revolves 
in  either  direction  with  the  semaphore  shaft.  The  motor,  in 
addition  to  operating  the  signal,  is  of  such  design  that  it 
will  also  hold  the  signal  in  the  proceed  positions  without  the 
intervention  of  the  ordinary  forms  of  electro-mechanical  slot 


Figs.    1814-1815.      Universal    Model    "2-A"    Direct    Connected    Signal    Mechanism,      no    Volt    D.    C.    Non-Auto- 
matic Control  Dynamic  Indication.     General  Railway  Signal  Company. 


and  finish  of  the  movement,  thus  allowing  the  motor  to  speed 
up,  after  the  switch  movement  has  been  completed,  for  the 
purpose  of  generating  sufficient  B.  M.  F.  to  furnish  a  strong 
and  positive  indication.  The  circuit  control  of  the  switch 
machine  is  identical  with  that  of  the  Model  2,  the  description 
on  pages  214-215  therefore  being  applicable  in  every  particular. 
Figs.  1814-1815  show  Model  2A,  110-volt  dynamic  indication 
signal,  the  circuits  for  which  were  described  in  connection  with 


or  other  retaining  devices.  When  the  signal  has  assumed  the 
desired  position  for  the  proceed  indication,  high-resistance  field 
windings  are  thrown  in  series  with  the  operating  fields  and  the 
armature  is  magnetically  locked  in  that  position.  No  me- 
chanical contact  of  any  kind  exists  between  the  moving  and 
stationary  parts  of  this  motor.  Due  to  the  fact  that  the  motor 
is  driven  backwards  by  the  mechanism  gearing  when  the 
signal  blade  is  returning  to  the  stop  position,  electric  means 


B 


Figs.  1816-1817.        Motor   for    ID  V.  D.  C.  Model  "2-A"  Signal. 


Fig.  1767.  The  signal  is  clamped  to  the  mast  by  means  of  a 
clamp  bearing,  which  enables  the  signal  to  be  mounted  anywhere 
on  new  or  existing  poles,  or  any  number  on  a  given  pole.  To 
Insure  proper  alignment,  the  driving  and  semaphore  shafts  are 
connected  by  a  coupling  which  lends  itself  to  a  simple  means 
of  locking  the  semaphore  in  the  normal  position,  thereby 
preventing  improper  operation  of  the  signal  by  any  outside 
agency. 


may  be  used  for  stopping  the  movement  of  the  signal  blade 
without  the  use  of  the  dash-pot  or  other  additional  me- 
chanical contrivances.  This  is  accomplished  in  the  last  few 
degrees'  movement  of  the  mechanism  by  the  generation  of 
the  current  necessary  to  tripping  the  indication  mechanism  on 
the  controlling  lever. 

The  circuit  breaker  is  a  complete  unit  connected  to  the  main 
operating   shaft    by    means    of   a    segmental    gear.     The    commu- 


1818-1822 


INTERLOCKING. 


225 


Figs.    1818-1819.     Universal  Model  "2A"   Direct   Connected   Signal   Mechanism,     no  Volt   D.   C.   Semi-Automatic 

Control— Dynamic  Indication.     General  Railway  Signal  Company. 


Fig.  1820.     Model  "2A"  Interlocking  Signal.     S.  P.  &  S.       Fig.    1821.      View    Showing    Lake    Street    Interlocking 
R.  R.  Plant.     Chicago  Terminal.     C.  &  N.  W.  Ry. 


Fig.  1822.     Unit  Type  Lever  Interlocking  Machine  (400  Levers)  Grand  Central  Terminal— N.  Y.  C.  &  H.  R.  R.  R. 

General  Railway  Signal  Company. 


226 


INTERLOCKING. 


Figs.  1823-1824 


Fig.  1823.     Rear  View  of  Unit  Type  Lever  Interlocking  Machine  (360  Levers). 

C.  &  H.  R.  R.  R. 


Grand  Central  Terminal.     N.  Y. 


tator  is  capable  of  being  equipped  with  14  circuits,  including 
those  for  the  local  control  of  the  signal,  and  such  contacts 
which  are  used  to  break  the  operating  current  of  the  signal 
proper  are  arranged  to  "snap"  over,  a  quick  break  being  essen- 
tial. 

In  the  semi-automatic  Model  2A  signal,  the  initial  free  move- 
ment of  the  mechanism  is  accomplished  by  having  one  shoulder 
of  the  coupling  so  cut  away  that  the  40-deg.  rotation  of  the 
driving  shaft  is  necessary  before  it  will  engage  with  the  sema- 
phore shaft.  Fig.  1819  shows  the  movement  by  which  the 


springs  are  put  under  tension,  the  two  coil  springs  being 
connected  to  the  driving  shaft  by  an  equalizer  and  crank, 
one  end  of  the  latter  being  fastened  to  the  main  sector  OD 
the  driving  shaft.  The  construction  is  such  that  the  backward 
tension  of  the  spring  is  neutralized  after  the  blade  has  moved 
a  few  degrees  from  the  stop  position,  so  that  the  springs  are 
in  no  way  depended  upon  for  the  restoration  of  the  blade 
to  normal.  With  the  exception  of  this  feature,  the  semi- 
automatic signal  is  the  same  as  the  regular  signal,  the  design 
of  its  mechanism,  therefore,  not  requiring  further  discussion. 


Fig.  1824.     Unit  Type  Lever  Interlocking  Machine   (360  Levers).     Grand  Central  Terminal. 

R.  R.     General  Railway  Signal  Company. 


N.  Y.  C.  &  H.  R. 


Figs.  1825-1829 


INTERLOCKING. 


227 


Fig.   1825.     Unit  Type  of  Lever  Interlocking  Machine       Fig.    1826.     Model    "2A"    Signals— Bridge   A.      Chicago- 
(360    Levers).      Grand    Central    Terminal.  Terminal,  C.  &  N.  W.  Ry. 

N.  Y.  C.  &  H.  R.  R.  R. 


SIGNAL  TOWER 


13  KIXD 

BATTERY      ROOM 

Track  Plan. 


CHECK  LOCK  LEVER  22 
24 


LEVER 

WHEN 

LOCKS 

1  

4—  (4)—  10 

4—15—19 

23 

4—  (17)  

24 

(4)..                  

9—5 

(4)—  (21)—  17  
(4)-(15)-19  

24 
23 

2                    

5—  (5)—  8 

5—21—17.  .  . 

24 

5—  (19)  

23 

(5)  

9 

(5)-(21)-17  
(5)—  (15)—  19  

24 
23 

3  

4 

5...                                      ..  ) 

( 

8                                        .      i 

7  

g 

7—5 

9 

5—  (5) 

5  .. 

(4)—  (3) 

(5) 

10... 

(3)—  4 

11               

19—  (19)—  21—  24—  17 

19 

(22) 

(19)  :  

23—14 

12' 

15—  (15)—  17—  19 

15 

(21)  —  24—  (22) 

(15)  :  .. 

23—14 

13                

17—  (17)—  15—  19 

17 

23—14 

(17)  

(22)—  24 

14  

15               .  .  ; 

( 

16  \ 

17  .              ..  ) 

( 

18  \ 

'9  :  / 

20..  .       ..         \ 

21  

22        

23  

19—  (1!))  —  17 

19  

15—  (15) 

24  

17—  (17)—  19 

17 

21—  (21) 

17(21)—  

15 

(17)  

15 

Locking  Sheet. 


CHECK  DOUBLE 

HOME      DWF       LOCK     SWITCH         5WITCH 


CHECK  CHECK 

LOCK       HOME       HOME      DWAUF      HOME      HOME      HOME      LOCK 

789 


DOUBLE  CHECK 

SWITCH         SWITCH      LOCK     DWARF      HOME, 


10       11        12       13       14       15       16       17       18       19       20      21       22      23      24 


U    U    U    U    LT~        LJULJULJUULJU        ~D~     ~D~        U    U    U    U 

Figs.    1827-1829.     Track   Plan,  Locking  Sheets   and   Dog  Chart.      Hudson    &    Manhattan    Railroad    Terminal.      Model 
2   Electric    Interlocking   Machine.     General  Railway  Signal   Company. 


228 


INTERLOCKING. 


Figs.  1830-1835 


Figs.  1830-1831.     Model  3  Solenoid  Dwarf    Signal.    General    Rai'way  Signal  Company. 


Figs.  1832-1833.     Model  2  Solenoid  Dwarf  Signal.     General  Railway  Signal   Company. 


Fig.   1834.     Model  "2A"  Dwarf  Signal.     Chicago 
Terminal,  C.  &  N.  W.  Ry. 


Fig.    1835.     Model   "2 A."    Dwarf    Signal.      New   York 
Central  Electric  Zone. 


Figs.  1836-1840 


INTERLOCKING. 


229 


Names   of   Parts   of   Model   2, 

Electric    Dwarf    Signal. 

Figs.  1836-1838. 

A  Rack 

B  Roller 

C  Shaft  for  B 

D  Magnet  Core,  Brass 

E  Cap  for  D 

F  Bolt 

G  Washer 


Figs.    1836-1838.      Details    of    Solenoid    Dwarf    Signals,    Figs.    1830-1833. 

(O   Is  Normally  off  Center,  Locking  the  Signal   in  the   Stop  Position.) 


H  Restoring  Spring 

I  Commutator,    Indication 

J  Pinion 

K  Collar 

L  Bottom  Support  for  H 

M  Armature 


N 
O 
P 

Q 

R 
S 


Yoke 

Crank 
.Tube,   Brass 

Cotter 

Washer 
Contact 


T    Insulating  Segment 

V     Operating  Rod 

W    Spring 

X    Elastic    Nut 

Y    Eye 

Z    Clamp  Screw 


a  a 


a 


Figs.   1839-1840.     Model  2  Solenoid  Dwarf    Signal.     General   Railway   Signal   Company. 


230 


INTERLOCKING. 


Figs.  1841-1850 


THE     UXIOV     SWITCH     &     SIGNAL    COMPANY. 

The  interlocking  machine,  an  end  and  a  front  elevation  of 
which  are  shown  in  Figs.  1841-1842,  and  a  rear  view  in  Fig. 
1851,  resembles  very  much  in  general  appearance  the  electro- 
pneumatic  machine,  Fig.  1955,  and  the  levers  have  the  same 
movements.  The  preliminary  movement,  limited  by  the  indica- 
tion latch,  effects  the  locking  of  all  levers  whose  movements 
•would  conflict  with  the  new  position  of  the  lever.  The  final 
movement,  which  can  take  place  only  after  the  indication  is 


received,  unlocks  all  levers  whose  movements  would  not  con- 
flict with  that  position  of  the  lever.  The  preliminary  move- 
ments, in  reverse  directions,  overlap  to  such  an  extent  as  to 
permit  a  range  of  movement  sufficient  to  throw  the  electric  con- 
trolling switch  from  one  controlling  position  to  the  other  at  the 
will  of  the  operator. 

The  switch  points  are  made  to  follow  the  movements  of  the 
lever  by  sending  a  current  through  one  or  the  other  of  two  in- 
dependent series  of  field  windings  On  the  switch  operating 


an 


Figs.  1841-1842.     Electric  Interlocking  Machine;  Views     Showing   Elevation    in   Section   and   Front   Elevation. 


] 

F  '  —  E 

~        ii 

1 

'  V 

Vl                   T 

V      V 

Figs.      1845-1848.      Indica- 
tion   Latches. 


Figs.  1843-1844.     Indication  Transformer. 


2  Latch  for  Switch  Lever 

3  Latch  for  Signal  Lever 


Figs.      1849-1850.      Indication 
Motor. 


Figs.  1851-1873 


INTERLOCKING. 


231 


motor,  which  causes  rotations  in  opposite  directions.  Each 
independent  switch  requires  one  lever,  but  any  two  switches 
which  are  to  be  operated  simultaneously,  as  two  switches  of  a 
crossover,  have  but  one  lever. 

The  signal  levers  stand  normally  in  the  middle  position  and 
are  moved  to  the  right  or  left  for  the  purpose  of  operating 
opposing  signals.  Two  or  more  signals,  governing  diverging 
routes,  are  also  controlled  by  one  lever  when  the  signals  are 
those  operated  by  one  motor,  as  for  instance,  when  two  or  three 
arms  are  placed  on  one  post.  The  selection  between  the  arms 
in  this  latter  case  is  effected  by  means  of  selectors,  operated  by 
the  switch  points  themselves,  or  by  the  levers  which  control 
the  movements  of  the  points. 


While  in  the  accompanying  illustrations  the  interlocking  ma- 
chine is  shown  equipped  with  a  stroke  completing  attachment, 
it  is  not  customary  to  apply  this  device.  The  stroke  complet- 
ing apparatus  comprises  a  swinging  arm,  loosely  pivoted  to  each 
lever  shaft,  and  pawls  carried  by  the  frames  of  the  indication 
segments  for  engaging  these  arms.  The  arms  are  all  connected 
by  means  of  a  bar  extending  the  full  length  of  the  machine, 
and  are  made  to  oscillate  by  means  of  a  motor  connected  to  the 
bar  through  an  eccentric.  When  an  indication  is  received,  the 
indication  latch  lifts  a  pawl  into  engagement  with  one  of  the 
swinging  arms  and  the  lever  is  thereby  rotated  through  the 
final  part  of  its  movement.  The  circuit  to  the  motor  is  con- 
trolled by  a  relay,  the  exciting  coil  of  which  is  placed  in  the 


Fig.   1851.     Electric  Interlocking  Machine,  View  Showing  Back  Elevation  Partly  in  Section. 


3a  n 


Figs.    1852-1853.      Detail    of    Lever. 


Figs.    1854-1873.     Details    of   Lever 
Connections,    Quadrants,    Indi- 
cation    Segments    and 
Guide. 


Names  of  Parts  of  Figs.  1854-1873. 


D  Indication  Segment  for  Switch  Lever  32 

E  Indication  Segment  for   Two-Position   Signal  Lever          33 

F  Indication  Segment  for   Three-Position  Signal  Lever         34 

G  Guide  for  Indication  Latdi  and  Segment  35 

24  Clamp,  Upper  Half  36 

25  Clamp,  Lower  Half  37 

26  Journal  for  Clamp  38 

27  Segment  for  Switch  Lever  39 

28  Segment  for  Two-Position  Signal  Lever  47 

29  Segment  for  Three-Position  Signal  Lever  49 

30  Guide  Base  55 

31  Bushing 


Jaw 

Long  Lever  Shaft 

Short  Lever  Shafts   (2  coupled) 

Indication  Segment  Shaft 

Strip  to  Support  Slate  Base  for  Circuit  Controller 

Quadrant  for  Switch  Lever. 

Quadrant  for  Two-Position  Signal  Lever 

Quadrant  for  Three-Position  Signal  Lever 

Machine  Screw 

Machine  Screw 

Set  Screzv 


232 


INTERLOCKING. 


Figs.  1874-1877 


main  lead  between  the  battery  and  the  machine.  Controlled  in 
this  way  the  motor  is  only  in  action  when  required  for  com- 
pleting the  stroke  of  a  lever. 

The  indication  part  of  the  system  is  worked  in  the  following 
manner :  The  commutator  of  the  motor,  in  addition  to  the 
parts  usually  found  on  a  direct-current  motor,  is  provided  with 


the  varying  position  of  the  segment  to  which  the  collector 
ring  is  attached.  This  undulating  current  induces  an  alter- 
nating current  in  the  secondary  of  a  transformer.  Figs.  1843- 
1844,  and  this  alternating  current  drives  a  small  induction 
motor,  Pigs.  1849-1850,  which  releases  the  indication  latch  and 
permits  the  completion  of  the  stroke  of  the  lever  on  the  ma- 


Figs.    1874-1875.     Electric  Switch   and   Lock  Movement  with    Electric    Clutch    and    Planetary    Reduction    Gear; 

Views   Showing  Plan  and   Side   Elevation. 


Figs.  1876-1877.     Electric  Switch  and  Lock  Movement  w  ith  Countershaft  Reduction  Gear  and  Mechanical  Clutch. 


a  collector  ring  and  a  brush,  bearing  thereon.  The  collector 
ring  is  connected  electrically  with  one  segment  of  the  com- 
mutator. At  the  end  of  the  movement,  the  automatic  controller 
changes  the  path  of  the  current  from  the  operating  brush,  bear- 
ing on  the  commutator,  to  the  indication  brush,  bearing  on  the 
collector  ring,  at  the  same  time  cutting  out  the  magnetic 
clutch.  The  motor  then  continues  to  run  light,  driven  by  cur- 
rent from  the  battery,  which  current  is  caused  to  undulate  by 


chine.  In  this  manner  the  indication  is  brought  about  by  utiliz- 
ing the  battery  current  which  is  transformed  into  an  alter- 
nating current.  The  indication  motor  previously  referred  to 
has  its  armature  shaft  in  a  vertical  position  ;  to  this  is  at- 
tached a  piece  of  centrifugal  apparatus  very  similar  in  construc- 
tion to  the  well  known  form  of  governor  used  on  the  steam 
engine.  The  rapid  rotation  of  the  armature  causes  the  weights 
to  separate,  and  through  a  combination  of  levers,  to  lift  the 


Figs.  1878-1881 


INTERLOCKING. 


233 


indication  latch  and  release  the  lever.  This  mode  of  construc- 
tion makes  it  necessary  to  have  a  rapid  rotation  of  the  indica- 
tion motor  armature  to  produce  the  desired  effect,  and  this 
rotation  can  be  secured  only  by  a  rapid  succession  of  alter- 
nating impulses  in  the  coils  of  the  motor.  A  direct  current 
through  these  coils  has  no  effect  other  than  to  hold  the  arma- 
ture against  rotation.  Single  impulses  which  may  be  caused 
by  making  or  breaking  a  circuit,  will  cause  the  armature  to 
move  through  not  more  than  ten  degrees,  and  a  succession  of 


these  working  the  lock  rod  and  detector  bar,  and  the  other  the 
switch,  connection  being  made  to  the  detector  bar  and  switch 
through  cranks.  The  lock  is  worked  direct  by  a  straight  bar 
which  slides  longitudinally  beneath  the  cam,  motion  being  Im- 
parted by  means  of  a  lug  fitting  the  cam  slot.  In  each  case  the 
cam  slot,  for  a  portion  of  Its  travel,  moves  in  a  plane  at  right 
angles  to  the  shaft,  so  that  while  that  portion  is  passing  the  lug 
on  the  driving  bar  or  crank,  no  movement  of  the  latter  takes 
place  ;  it  is  only  while  the  lug  is  engaged  by  the  diagonal  portion 


ttSN     X      T        X      N' 


Names  of  Parts  of  Solenoid. 

Circuit     Controller;     Figs. 

1878-1881. 

A  Solenoid 

B  High  Resistance  Coil 

C  Low  Resistance  Coil 

D  Core 

E  Jaw 


F 
G 


Lever 

Lever  Support 


H     Contact  Operating  Rod 


Contact  Bridge 
Contact 


K  Contact 

L  Contact 

M  Contact 

N  Slate  Block 

O  Slate  Block 

P  Terminal  Binding  Screws 

Q  Terminal  Binding  Screws 

R  Terminal  Binding  Screws 

S  Terminal  Binding  Screws 

T  Latch 

U  Porcelain  Resistance  Grid 

V  Base 

X  Contact 

Z  Connecting  Spring 


Figs.  1878-1881.     Solenoid  Safety  Circuit  Controller  for  Switch  Movement, 
Views  Showing  Plan,  Elevation  and  Wiring  Diagram. 


such  impulses,  following  each  other  as  rapidly  as  it  is  pos- 
sible to  make  and  break  a  circuit  by  hand,  will  cause  only  a 
step  by  step  movement  of  the  armature,  the  armature  coming 
to  a  full  stop  at  the  end  of  each  step,  so  that  impulses  produced 
in  this  manner  will  not  cause  the  weights  to  move  from  their 
position  of  rest  against  the  armature  shaft. 

Fig.  1874  is  a  plan  and  Fig.  1875  a  side  elevation,  showing 
a  switch  and  its  operating  mechanism.  The  switch  and  lock 
movement  is  driven  by  a  direct  current  motor  of  about  l1/^ 
h.p.,  designed  to  be  operated  at  110  volts.  The  shaft  of  this 
motor  is  connected  by  means  of  a  magnetic  clutch  to  a  shaft 
extension  in  the  same  line,  working  a  cam  drum,  which  oper- 
ates the  switch  and  lock.  Intermediate  between  the  magnelic 
clutch  and  drum,  there  is  a  reduction  gearing  with  a  speed 
ratio  of  25  to  1.  There  are  two  cams  on  the  drum,  one  of 


of  this  slot,  that  movement  Is  imparted  to  the  switch  or  lock 
mechanisms.  The  operation  is  as  follows  :  When  the  drum  Is  re- 
volved by  the  motor,  the  lock  rod  and  detector  bar  immediately 
begins  to  move,  and  as  soon  as  these  have  completed  part  of 
their  stroke,  their  motion  ceases  and  the  movement  of  the 
switch  begins.  After  the  switch  has  been  moved  over  against 
the  stock  rail,  further  motion  of  the  lock  bar  locks  the  switch 
and  at  the  same  time  operates  a  knife  switch  which  opens  the 
control  circuits  and  closes  the  indication  circuit.  The  cam  drum 
is  reversible,  so  that  the  movement  can  be  operated  either  right 
or  left  (the  position  of  the  motor  and  clutch  remaining  the 
same)  by  changing  the  drum,  end  for  end.  The  motor,  clutch  and 
drum  are  all  attached  to  a  steel  base  plate.  The  direction  of 
rotation  for  reversing  the  switch  is  controlled  by  means  of 
two  field  windings,  one  of  which  Is  cut  out  while  the  other  is 


234 


INTERLOCKING. 


Figs.  1882-1883 


in    circuit.      When    the   switch   is   to   be   thrown   in   the    reverse  The  magnetic  clutch   permits  of  breaking  the   motor  connec- 

direction,  the  lever  on  the  interlocking  machine  merely  changes  tion  with  the  throwing  mechanism  at  the  proper  time  ;  and  the 

the  connection  of  the  operating  circuit  to  the  other  field  wind-  absence   of   a    rigid    connection   prevents    breaking   or   straining 

ing.  ot!   the    parts    if    the    movement    of    the    switch    should    become 


NORMAL    WIRE,    OPERATION  i  INDICATION.-— 

REVERSE       •  

WIRE   COMMON   TO   BOTH   CIRCUITS.* 


COMMON 54 


Fig.  1882.     Control  and  Indication  Circuits  for  a  Single  Switch;  Beginning  of  Reverse  Movement. 


NORMAL    WIRE.  OPERATION    &  INDICATION. 

REVERSE       H  . 

WIRE    COMMON   TO   BOTH    CIRCUITS 


Fig.    1883.     Operating    Circuits   for    Crossover;    All    Parts    in    Normal  Position. 


Fig.  1884 


INTERLOCKING. 


235 


blocked,  the  blocking  of  the  switch  merely  causing  the  clutch 
to  slip  until  a  fuse  is  blown  on  the  interlocking  machine.  If 
the  switch  is  found  to  be  blocked,  it  can  be  thrown  back  by 
simply  reversing  the  lever,  and  this  can  be  done  quickly 
enough  to  avoid  blowing  the  fuse. 

Figs.  1876-1877  show  this  type  of  switch  and  lock  movement 
provided  with  a  countershaft  reduction  gear  and  also  a  mechan- 
ical clutch  instead  of  the  electro-magnetic  clutch  just  described. 
The  safety  controller,  which  automatically  cuts  out  a  switch 
motor  if  the  wires  become  improperly  connected,  combines  in 
one,  the  functions  of  two  electro-magnetic  circuit  controllers. 
The  function  of  one  is  to  open  the  motor  circuit  when  the 
lever  movement  is  completed,  and  of  the  other  to  open  the 
next  operating  circuit  when  it  is  energized  improperly  by  con- 
nected wires,  and  thus  to  prevent  a  wrong  movement.  The  in- 
strument which  is  illustrated  in  Figs.  1878-1881,  comprises 
two  solenoids  A  and  A',  fixed  to  a  cast  iron  base  V.  Each 
solenoid  has  a  movable  core  D,  connected  by  means  of  a  jaw 
E  to  a  lever  F.  The  lever  F  is  pivoted  at  its  middle  to  a 
fixed  support  G  and  is  connected  at  its  upper  end  to  a  rod  H, 
free  to  move  longitudinally.  The  rod  H  carries  a  contact 


At  the  beginning  of  a  movement,  current  flows  through 
coils  C  and  B,  and  resistance  U  in  series,  and  draws  in  the 
core  D,  causing  the  bridge  I'  to  connect  L'  and  M',  which  shunts 
the  coils  B  and  U,  so  that  the  operating  and  indicating  cur- 
rents flow  only  through  the  coil  C,  of  a  very  low  resistance, 
but  having  sufficient  turns  to  hold  the  core  D  in  place.  The 
bridge  I  will  touch  J  and  K  before  I'  touches  L'  and  M',  so 
that  if  the  current  happened  to  come  from  a  foreign  source 
without  the  lever  having  been  moved,  current  would  also  flow 
from  the  last  operating  wire,  which  is  still  in  connection  with 
battery,  through  coils  C',  B',  bridge  I,  and  the  motor,  and 
would  hold  I'  away  from  L'  and  M',  by  drawing  in  the  core 
D'.  This  current  will  run  the  motor  light  in  the  direction  it 
ran  in  making  the  last  movement  without  energizing  the 
clutch.  The  contact  K  is  provided  with  a  head  on  its  inner 
end,  which  makes  connection  with  a  contact  X,  when  K  is 
pushed  outward  by  the  spring,  but  when  K  is  pushed  in  by  the 
bridge  I,  it  is  separated  from  X.  The  object  of  this  is  to 
cause  the  cut-off  current  to  flow  only  through  the  safety  con- 
tacts J  and  K,  and  thus  afford  a  test  of  their  condition  at  each 
movement  of  the  switch. 


T3R 


Fig.    1884.     Control  and   Indication   Circuits  for  Electric  Interlocking    Signals. 


bridge  I,  which  will  connect  the  contacts  J  and  K  when  the 
core  D  is  drawn  into  the  solenoid,  and  will  connect  the  con- 
tacts L  and  M  when  the  core  D  is  drawn  outward.  The  levers 
F  and  F'  are  connected  near  the  lower  ends  by  a  spring  Z, 
which  causes  the  bridge  I'  to  connect  I/  and  M',  when  the  core 
D  is  drawn  into  its  solenoid  A  to  nearly  the  full  extent.  Sim- 
ilarly the  contact  bridge  I  is  made  to  connect  L  and  M  when 
the  core  D'  is  drawn  into  the  solenoid  A'.  The  contacts  J  and 
K  are  carried  by  the  slate  block  N,  with  springs  interposed  so 
that  they  may  be  pushed  in  about  3-16  in.  The  contacts  L  and 
M  are  fixed  to  the  slate  block  O.  The  relation  of  the  parts  is 
such,  that  the  bridge  I  touches  the  contacts  J  and  K,  while  the 
core  D  is  still  3-16  in.  from  its  complete  inward  stroke,  and 
tho  bridge  I'  touches  L'  and  M'  with  the  core  D  about  1-16  in. 
from  its  full  inward  stroke.  These  clearances  are  allowed  for 
making  good  contact.  Each  solenoid  has  two  coils  of  wire. 
The  ceil  C  has  100  turns  of  No.  13  B.  &  S.  and  the  coil  B  1100 
turns  of  No.  15  B.  &  S.  The  resistances  U  and  U',  each  of 
20  ohms,  are  in  series  with  the  coils  B  and  B'  at  the  start- 
ing of  a  movement,  and  the  circuits  including  them  may  be 
called  the  starting  circuits.  The  coil  B  is  connected  to  term- 
inals r  and  Q,  and  the  coil  C  is  connected  to  the  terminals  E 
and  S. 


When  the  core  D  is  drawn  completely  into  the  solenoid  A, 
the  latch  T  drops  into  the  path  of  a  projection  on  the  lever  F'. 
so  that  if  the  magnet  A'  is  energized  while  A  is  still  holding  its 
core,  the  core  D'  will  be  stopped  by  the  latch  T  before  it  puts 
the  bridge  I'  against  J'  and  K'.  A  similar  latch,  T',  stops  the 
core  D  under  similar  conditions.  These  latches  come  into  play 
in  the  action  of  the  cut  off  current  last  above  mentioned.  If 
in  that  case  the  bridge  I'  were  allowed  to  move  far  enough  to 
touch  J'  and  K',  the  safety  circuit  to  be  mentioned  later  would 
be  temporarily  closed  and  cause  sparking  at  the  contacts. 

The  circuits  of  a  single  switch  can  be  understood  from  an 
inspection  of  Fig.  1882.  In  the  position  of  the  parts  as  shown, 
which  is  the  beginning  of  the  reverse  movement,  current  will 
flow  from  battery  1  through  primary  2,  fuse  3,  wire  4,  spring 
5.  bridge  11  (11,  Ha  and  11  are  one  piece  on  machine),  spring 
9,  wire  14,  field  16,  wire  18,  coil  C  of  A,  connector  26,  coil 
B  of  A,  wire  20,  contacts  K'  and  X',  resistance  U,  wire  22, 
contacts  37  and  38  of  knife  switch  33,  wires  23  and  45,  clutch 
52  by  brushes  50  and  51,  armature  53  by  brushes  49  and  47, 
thence  by  common  wire  to  battery.  This  current  will  energize 
the  magnet  A,  the  bridge  I  will  connect  J  and  K,  and  the  bridge 
I'  will  connect  L'  and  M'.  The  above  circuit  remains  the  same 
up  to  wire  18,  thence  through  coil  C  of  A,  wire  28,  contact  M', 


236 


INTERLOCKING. 


Figs.  1885-1886 


bridge  I',  contact  L',  wire  30,  contact  35,  knife  33,  contact  38, 
to  wire  23,  whence  it  is  the  same  as  above.  The  current  in  the 
coll  C  holds  the  core  D  and  the  bridges  I  and  I'  in  position 
last  noted. 

When  the  switch  movement  is  completed,  the  knife  33  is 
moved  from  contact  38  to  contact  36,  still  remaining  in  contact 
with  35.  This  cuts  off  the  current  from  the  clutch  52,  and 
causes  it  to  flow  through  wires  43  and  46,  indication  brush 
48,  armature  53, -brush  47,  and  common  to  battery-  The  cur- 
rent still  flows  through  the  coil  C,  thus  holding  I  and  I'  in 
positions  noted.  The  current  entering  the  armature  53,  Jby  the 
way  of  the  brush  48,  which  bears  on  a  ring  connected  to  a  seg- 
ment of  the  commutator,  is  thereby  rendered  pulsating  in  char- 
acter. In  flowing  through  the  primary  2  of  the  transformer, 
it  develops  magnetism  of  a  like  character  in  the  iron  core. 
This  in  turn  induces  alternating  current  in  the  secondary  coil 
55,  which  flows  through  the  induction  motor  56,  by  means  of 
which  the  latch  is  lifted,  thus  releasing  the  lever  to  make  its 
final  movement. 

The  final  movement  of  the  lever  puts  the  bridge  12  in  con- 
tact with  spring  contacts  8  and  10,  which  closes  a  branch  cir- 


movement  of  the  mechanism  operated  by  armature  53.  The 
current  in  this  last  circuit  causes  the  armature  53  to  com- 
plete the  movement,  and  indicate,  which  it  does  as  explained 
in  the  description  of  the  single  switch. 

The  action  of  the  crossover  mechanism  may  be  briefly  stated 
as  follows  :  The  armature  53,  which  is  governed  by  the  safety 
controller  starts  the  movement,  and  after  a  short  preliminary 
movement,  opens  its  own  circuit,  and  closes  that  of  153. 
Armature  153  then .  completes  its  movement,  and  again  closes 
the  circuit  to  53,  which  then  completes  its  movement,  and  in- 
dicates. 

To  explain  the  action  of  the  safety  controller,  in  protecting 
against  stray  currents,  reference  will  be  made  to  Fig.  1883, 
which  shows  a  lever  in  complete  normal  position.  Suppose  a  live 
wire  to  be  connected  with  wire  14  at  Y.  Current  would  flow 
through  the  magnet  A,  just  the  same  as  though  the  lever  had 
been  reversed.  This  would  cause  the  bridge  I  to  touch  .T  and 
K,  when  a  circuit  would  be  closed  and  current  would  flow 
from  battery  1,  through  2,  3,  4,  6,  11,  10,  13,  contacts  139  and 
140,  wire  113,  field  15,'  wire  17,  coils  C'  and  B'  of  A',  19,  K. 
I,  J,  31,  32,  armature  53  by  brushes  49  and  47,  to  common 


Figs.   1885-1886.     Style  "B"   High   Signal   Mechanism,   Adapted   to   Electric  Interlocking. 


cuit,  and  current  flows  from  armature  53  by  way  of  brush  49, 
wires  32  and  31,  contact  J,  bridge  I,  contact  K,  wire  19,  coil 
B'  of  A',  connector  25,  coil  C'  of  A',  wire  17,  field  15,  wire  13, 
spring  10,  bridge  12,  spring  8,  wire  57,  motor  56,  and  sec- 
ondary 55  in  parallel,  and  resistance  58  to  battery.  This  cur- 
rent energizes  magnet  A',  draws  in  its  core  D',  and  pulls  the 
bridge  I'  away  from  contacts  L'  and  M',  thus  cutting  off  all 
current. 

Fig.  1883  shows  a  crossover  with  all  parts  in  normal  posi- 
tion. To  reverse  the  crossover,  the  bridge  11  will  be  moved  by 
the  lever  to  connect  the  contacts  5  and  9,  when  current  will  flow 
from  battery  1  through  2,  3,  4,  5,  11,  9,  14,  field  116,  wire  60, 
contacts  137  and  138  of  knife  switch,  wire  62,  contacts  64  and 
65  of  knife  switch,  field  16,  wire  18,  coil  C  of  A,  connector  26, 
coil  B  of  A,  wire  20,  contacts  K'  and  X',  resistance  U,  wire  22. 
contacts  37  and  38  of  knife  switch,  wires  23  and  45,  clutch  52, 
armature  53,  thence  through  common  to  battery.  This  current 
energizes  magnet  A,  thereby  causing  the  bridge  I  to  connect  J 
and  K,  and  bridge  I'  tcx  connect  L'  and  M'.  The  connection  of 
I/  and  M'  shunts  the  coil  B  and  resistance  U  out  of  the  motor 
circuit,  as  explained  in  connection  with  the  single  switch.  When 
the  mechanism  connected  to  armature  53  has  moved  a  short 
distance,  the  knife  switch  63  is  shifted  from  contacts  64  and 
65,  to  contacts  66  and  67,  which  breaks  the  circuit  through 
armature  53,  and  continues  the  circuit  from  wire  62  through 
contacts  66  and  67,  wires  123  and  145,  clutch  152,  armature 
153,  thence  through  common  to  battery.  The  switch  operated 
by  motor  153  then  makes  its  complete  movement,  at  the  end 
of  which,  the  knife  133  is  shifted  from  contacts  137  and  13S 
to  contacts  135  and  136,  which  stops  the  current  through  field 
116  and  armature  153,  and  continues  the  circuit  from  wire  11 
through  contacts  135  and  136,  wire  114  to  field  16,  thence  it  is 
tho  same  as  that  above  traced,  which  caused  the  preliminary 


This  current  would  energize  magnet  A',  and  would  hold  the 
bridge  I'  away  from  the  contacts  I/  and  M'.  It  would  also  turn 
the  armature  53  in  the  direction  it  ran  in  making  the  last 
movement,  because  tlie  current  goes  through  the  same  field 
15  that  was  then  used.  The  rotation  of  the  armature  produces 
a  back  E.  M.  F.,  which  limits  the  current  to  such  a  small 
amount  that  there  is  no  danger  of  burning  out  the  magnet  A'. 
This  condition  would  continue  as  long  as  the  fault  remained. 
When  this  Is  removed,  the  apparatus  replaces  itself  in  proper 
condition  for  use.  If  the  contact  had  occurred  at  Y'  on  wire 
114,  the  action  would  be  the  same. 

For  high  signals,  use  is  made  of  the  ordinary  Style  "B" 
electric  semaphore  (See  Page  69),  with  the  addition  of  a  third 
brush  to  the  motor,  to  give  the  indication  in  a  manner  similar 
to  that  described  for  the  switch  machine,  with  other  slight 
changes  made  necessary  by  the  use  of  a  higher  voltage.  The 
high  signal  mechanism  is  illustrated  in  Figs.  1885-1886. 

The  dwarf  signal,  Figs.  1887-1888,  is  actuated  by  an  electric 
motor,  similar  in  all  respects  to  that  used  in  connection  with 
the  high  signals.  The  motor  drives,  by  means  of  a  worm  gear, 
a  horizontal  shaft  to  which  the  armature  of  an  electro-magnetic 
clutch  is  fixed.  The  other  part  of  the  clutch,  enclosing  the  ex- 
citing coil,  is  fitted  loosely  on  the  shaft.  This  loose  part  of  the 
clutch  has  a  crank  pin  affixed,  to  which  the  operating  rod  of 
the  signal  is  attached.  When  the  signal  is  at  normal  or  stop 
position,  the  crank  pin  is  vertically  under  the  shaft :  when 
clear,  the  crank  pin  is  about  45  degrees  above  the  horizontal. 
The  exciting  coil  of  the  clutch  is  connected  in  series  with  the 
motor,  and  when  energized  by  the  operating  current,  both  the 
motor  and  clutch  are  excited,  the  first  causing  the  clutch  arma- 
ture to  rotate,  and  the  second  causing  the  loose  part  of  the 
clutch  to  adhere  to  the  armature  and  move  with  it.  When 
tne  signal  reaches  the  clear  position,  a  circuit  switch  cuts 


Figs.  1887-1889 


INTERLOCKING. 


23? 


in  sufficient  resistance  to  reduce  the  holding  clear  current  to 
a  very  small  amount  and  to  stop  the  motor.  The  dwarL' 
signal  is  locked  in  the  normal  position  by  means  of  a  hook- 
shaped  formation  on  the  eye  of  the  operating  rod,  which 
engages  with  the  shaft  carrying  the  clutch,  if  the  rod  is 
moved  upwardly  a  very  short  distance.  Sufficient  lost  motion 
is  allowed  in  the  crank  pin  hole  to  permit  a  slight  upward 
movement  of  the  rod  without  turning  the  clutch. 

The  signals  are  protected  against  improper  movements  due 
to  stray  currents,  by  means  of  a  fuse  placed  in  the  signal 
operating  circuit  between  the  slot  coil  and  the  motor.  When 
the  signal  lever  is  in  the  normal  position,  the  indication  wire 
is  connected  to  the  common  w're,  and  as  the  indication  wire 


consequently  in  this  case  the  field  magnets  would  not  be  ener- 
gized so   that   the   armature   would  not   rotate. 

Fig.  1884  shows  the  arrangement  of  signals  at  a  turnout 
from  a  main  track.  The  two  high  signals  are  operated  by 
lever  1,  the  single  arm  signal  in  the  right-hand  position  of 
the  lever,  and  the  double  arm  in  the  left-hand  position.  Se- 
lection between  the  two  arms  of  the  high  signal  is  effected 
by  the  switch  box  on  switch  2.  The  dwarf  signal  is  controlled 
by  lever  3  in  its  right-hand  position.  Lever  1  is  shown  re- 
versed to  the  left,  and  upper  arm  of  1-L  is  clear.  The  current 
for  clearing  this  signal  flows  from  battery  5,  through  primary 
6  of  indication  transformer,  fuse  .35,  switch  9,  contacts  10 
and  12a,  wire  36,  contact  34,  wire  37,  series  slot  coil  of  15a, 


OPERATION    WIRE 

INDICATION 

COMMON 


Fig.     1889.     Circuits    for    Signal     with    Safety    Circuit 
Control. 


is  also  connected  to  the  control  wire  at  the  signal  motor,  both 
being  connected  to  the  same  brush  on  the  armature,  a  current 
which  might  reach  the  control  wire  would  be  short  circuited 
back  to  battery  through  the  indication  wire,  and  would  cause 
a  very  heavy  current  to  flow  and  blow  the  fuse  in  the  operating 
circuit,  thus  cutting  off  current  from  the  signal  motor  and 
preventing  a  false  movement.  If  a  contact  with  a  foreign 
source  should  occur  beyond  the  fuse,  it  would  also  be  beyond 
the  slot,  so  that  the  slot  magnet  would  not  be  energized  and 
the  signal  would  not  clear.  The  same  arrangement  is  followed 
in  reference  to  the  safety  controller  in  connection  with  the 
switch  motor.  The  coils  of  the  magnets  referred  to  are  both 
placed  between  the  fieW  coils  of  the  motor  and  the  armature, 
so  that  if  the  contact  should  occur  beyond  these  protecting 
magnets,  it  would  also  be  beyond  the  field  magnet  coils,  and 


Motor  Dwarf  Signal. 


contacts  29a,  17a,  75a,  fuse  74a,  field  coil  18,  brush  22a, 
armature  of  signal  operating  motor,  brush  23a,  wire  48,  to 
common.  When  the  signal  is  clear,  the  contact  17a  is  separated 
from  29a  and  75a,  but  this  break  is  shunted  by  the  shunt 
coil  of  slot  magnet  15a,  and  the  resistance  28a,  which  permits 
only  a  small  current  to  flow,  but  sufficient  to  hold  the  signal 
clear.  To  put  the  signal  normal,  the  lever  is  moved  toward 
normal  position  until  stopped  by"  the  indication  latch,  in  which 
position  10  makes  contact  with  13a,  but  is  separated  from  12a. 
The  separation  of  10  and  12a  breaks  the  circuit  through  the 
holding  coil  of  the  slot  magnet,  and  allows  the  signal  to  go 
to  normal  position.  When  the  signal  is  normal,  16a  makes 
contact  with  30a,  and  completes  a  circuit  so  that  current 
flows  from  battery  5  through  primary  6,  fuse  35,  switch  9, 
contacts  10  and  13a,  wire  39,  contacts  30a,  16a,  76a,  30b,  16b, 
76b,  field  coil  19a,  tongue  25a  of  centrifugal  controller,  contact 
27a,  brush  22a,  armature  of  signal  motor,  brush  23a,  and 
wire  48,  to  common.  This  causes  the  signal  motor  armature 
to  rotate,  and  when  it  has  acquired  sufficient  speed,  the  tongue 
25a  is  moved  over  to  the  contact  26a,  when  the  current  will 
enter  the  armature  through  the  brush  24a  and  collector  ring 
2 la,  instead  of  the  brush  22a.  This  causes  the  current  to 
undulate  and  produces  undulating  magnetism  in  the  core  of 
the  transformer,  thereby  inducing  an  alternating  current  in 
the  secondary  coil  7  of  the  indication  transformer,  which  flows 
through  the  coils  of  the  indication  motor  8,  lifts  the  latch 
by  means  of  centrifugal  action  and  releases  the  lever,  per- 
mitting it  to  be  put  in  normal  position. 

If  the  switch  2  had  been  reversed,  the  contact  arm  33, 
instead  of  34,  would  have  been  in  contact  with  control  wire 
36,  and  the  current  would  have  passed  from  wire  36  through 
contact  33,  wire  38,  slot  magnet  15b,  and  contacts  29b,  17b 
and  75b.  This  would  have  cleared  the  lower  arm.  The  circuits 
for  the  single  arm  high  signal,  and  the  dwarf  signal  are  in 
every  respect  similar  to  those  just  described.  The  clutch  84  of 
the  dwarf  signal  replaces  the  slot  magnet  15  of  the  high 
signal. 

Fig.  1889  illustrates  a  safety  controller  for  signals,  intended 
to  take  the  place  of  the  fuse  74.  It  is  superior  to  the  fuse  in 


238 


INTERLOCKING. 


Figs.  1890-1891 


some    respects,    as   it   replaces   itself   ready  for  operation    when  signal   operating  current,  as  is  the   case  with  the  fuse.     It  is 

the  fault   is   removed,    and    is    independent   of   the    strength    of  similar    in   general    appearance    and   mode   of   operation   to    the 

current.      Of   course  a   certain   minimum   current  is  required   to  common    polarized    relay,    but   has   no   permanent  magnet.      The 

operate    it,    but   this    minimum    need    not    be    greater    than    the  permanent   magnet   of   the    common   polarized    relay    Is    replaced 


Fig.   1890.     Circuits  for  Single  Switch;  Lever  and  Switch  Normal. 


CIRCUIT  OF  STARTING  CURRENT +44+" 

CIRCUITS  NOT  CARRYING  CURRENT 


I  I  I  I  I   I   I  I   I  I   I  I  I  I  I   I  I  I  I  IN  I  I  I  I  I  I   I -II 


Fig.    1891.     Circuits   for  Single  Switch;   Switch    Normal  Lever    Against    Reverse    Stop;    Starting  Circuit   for    Re- 
verse Movement  Energized. 


Figs.  1892-1893 


INTERLOCKING. 


239 


in  this  instrument  by  the  single  spool  electro-magnet  A.     The  flow  in  a  certain  direction  relatively  to  each  other.     The  signal 

double    electro-magnet    I! — B'    is    the    usual    electro-magnet    of  control   circuit  is  taken  through  the  magnet  A,   the  indication 

the  polarized  relay.     To  move  the  armature,  therefore,  requires  circuit    through    magnet    B — B',    and    the    connection    of    the 

current    in    both    A    and    B — B',    and    these    two    currents    must  signal    motor   to   common,   goes   through    the  contacts  C   and   B, 


CIRCUIT  OF  OPERATING  CURRENT +H+    •- 

CIRCUIT  NOT  CARRYING  CURRENT— 


I  1  I  I  I  I   I  I  I  I  I   I  I  I  I  I   I  I  I  I  I  I  I  I  I  I  I  I  1  I 


I  I  I  I  M  I  I  I   I  I  I  I   I  I  I  I  I  I  I  1111(111  I 


rig.    1892.     Circuits    for   Single    Switch;    Lever   Against  Reverse    Stop.      Right-Hand    Contact    Bridge    of    Circuit 
Controller    Has    Moved   Against    the    Back    Contacts;  Switch   Beginning  to   Move  from  Normal  to  Reverse. 


I  i  M  I  I  I  I   I  I  I  I  I  I  I  I  I  I  I  I  i  I  i  i  i  i  I  I  i 


CIRCUIT    OF  PRIMARY   INDICATION 

CURRENT -H-H- 

CIRCUIT  OF  SECONDARY  WDICATION 

CURRENT -*-#- 

CIRCUITS  NOT  CARRYINQ 

CURRENT 


Fig.    1893.     Circuits    for    Single    Switch;    Lever    Against  Reverse    Stop;    Switch    Reversed.      Knife    Switch 
Actuated  by  Mechanism  Has  Opened  Operating  Circuit   and   Closed    Indication    Circuit. 


240 


INTERLOCKING. 


Figs.  1894-1895 


controlled   by  the  relay.     When  the  signal  is  operating,   current  circuit  closed.      When   the  signal  lever  is  normal  the   indication 

flows   only   in  A,   when   it  is  indicating,   the   current   flows  only  wire  is  connected  to  common  at  the  lever.     If  then  a  live  wire 

In   B — B',    and   in  neither  case   is  any  effect   produced   on   the  should   make   contact   with   the   control   wire,    a    current   would 

armature  which  remains  stationary,  holding  the  common  return  flow    through    slot   magnet    15,   contacts    29    and    75,    magnet    A, 


CIRCUIT   Of  STOPPING   CURRENT.- +++ 

CIRCUIT   NOT  CARRYING  CURHENT. 


Fig.    1894.     Circuits    for    Single    Switch;    Lever    and     Switch    Reversed;    Stopping    Circuit    Closed    by    Final 

Movement  of   Lever. 


Fig.     1895.     Circuits    for    Single    Switch;    Lever    and       Switch   Reversed;   Stopping  Current  Has  Opened  Bat- 
tery   Circuit   by   Moving    Right   Contact    Bridge    of   Circuit    Controller   to   Center. 


Figs.  1896-1897 


INTERLOCKING. 


241 


Fig.  1896.  Circuit  for  Single 
Switch;  Lever  and  Switch  Re- 
versed. Battery  Current  Having 
been  opened  by  Right-Hand 
Contact  Bridge  of  Circuit  Con- 
troller, the  Left-Hand  Contact 
Bridge  Returns  to  Center. 


H«l 


r 


Fig.  1897.  Circuits  for  One- 
Arm  Dwarf  Signal;  Lever  and 
Signal  Normal. 


•II   III 


H«W«|H| 

^!!I 1 


242 


INTERLOCKING. 


Figs.  1898-1899 


I 


be 
c/5 

•o 

c 
rt 


rt 

bo 
175 

JS 
_bc 

K  rt 

E  u 


c 
O 


bo 


Held  coll  18,  contacts  27  and  25,  field  coil  19,  magnet  B — B', 
contacts  76  and  30,  thence  through  indication  wire  to  coiii- 
mon.  This  would  energize  both  magnets  A  and  B — B',  and 
the  connections  are  so  arranged  that  the  direction  of  flow 


is    right    to   move  the   armature   C   away   from    the   contact   I) 
and  thus  open  the  motor  return  circuit.    This  condition  woultM 
l>e  maintained  until   the  fault   is   removed,  when   the  armature' 
would  replace  itself  In  contact  with  D. 


Figs.  1900-1902 


INTERLOCKING. 


243 


244 


INTERLOCKING. 


Figs.  1903-1906 


Fig.     1903.       Cir- 
cuits   for    Two- 
Arm    High    Sig- 
nal; Lever  Signal 
and    Switch   in 
Normal    Position. 


Figs.    1904-1906. 
Electric    Switch 
and    Lock   Move- 
ment.    Views 
Showing    Dimen- 
sions   and    Fram- 
ing   of    Ties    and 
Location  of 
Safety    Circuit 
Controller. 


H  —  gf  —  i 

i 

'ui 

b 

'o 

x 

0 

Ul 

p 

i 

1 

Figs.  1907-1911 


INTERLOCKING. 


245 


MULTIPLE    UXIT    ELECTRIC    INTERLOCKING    MACHINE. 

The  machine  derives  its  name  from  the  fact  that  each  lever 
Is  an  independent  unit  in  itself  and  may  be  removed  by  taking 
out  two  screws. 


Fig.     1907.     Multiple     Unit     All-Electric     Interlocking 

Machine.     Eight  Levers.     Union  Switch 

&   Signal    Co. 


The  lever  movements  are  novel ;  the  first  is  longitudinal 
movement,  actuating  the  mechanical  locking  in  a  similar  man- 
ner to  the  latch  on  a  mechanical  machine.  The  intermediate 
movement  is  in  the  arc  of  a  circle  and  operates  controllers  for 
the  switch  or  signal  circuits.  The  final  movement  is  automatic 
and  takes  place  after  the  indication  has  been  received,  complet- 
ing the  movement  of  the  locking  exactly  the  same  as  on  Figs.  1908-1909.  Mechanism  for  High  Voltage  Motor- 
mechanical  latch  locking  machines.  Driven  Dwarf  Signal  Slot-Arm  Type. 


SECTIONAL  SIDE  VIEW 


Figs.   1910-1911.     Mechanism  for  Solenoid  Dwarf  Signal. 


SECTIONAL   END  VIEW 


246 


INTERLOCKING. 


Figs.  1912-1919 


SLOT-ARM    DWARF    SIGNAL. 

The  dwarf  signal  shown  in  Fig.  1912  is  actuated  by  an  elec- 
tric motor,  similar  in  all  respects  to  that  used  in  connection 
with  high  signals.  The  operation  is  as  follows : 

When  the  signal  is  in  the  stop  position  and  current  is  applied 
to  clear  it,  current  passes  through  the  slot  coils  and  motor 
in  multiple.  The  motor  revolves  the  gears,  which  in  turn  by 
means  of  a  crank  on  one  of  the  gears,  carries  the  slot  arm  up 
and  the  signal  assumes  the  clear  position.  When  the  slot  coils 
are  de-energized  the  armature  falls  away  from  the  coils,  re- 
leases the  slot  arm  latch  and  the  signal  returns  to  the  stop 
position  by  gravity. 


MOTOR    DWARF    SIGNAL. 

This  signal  is  for  use  in  connection  with  110 
interlocking  work  and  is  arranged  to  wrrk  as  a 
signal  in  the  upper  or  lower  quadrant. 


volts   d.    c. 
two-position 


Fig.    1912.     Slot-Arm  Dwarf   Signal. 
Signal   Company. 


Union    Switch    & 


C 

Figs.        191,3-1918.     One-Arm       Motor-Driven       Dwarf 
Signals.     Slot-Arm  Type.     60  and  90  Deg.   Lower 
Quadrant   and  90   Deg.   Upper   Quadrant   Indi- 
cations.    Union  Switch  &  Signal  Company. 


Fig.    1919.     Union    Solenoid    Dwarf    Signal. 


I   Fig.  1920 


INTERLOCKING. 


247 


FEDERAL      SIGNAL     COMPANY. 

The  machine  is  in  appearance  a  miniature  Saxby  &  Farmer 
mechanical  interlocking  machine  but  fitted  with  locking  of 
the  Stevens  type  similar  to  that  used  in  the  low  pressure 
pneumatic  system,  arranged,  however,  in  a  horizontal  instead 
of  a  vertical  plane.  The  machine  is  equipped  with  circuit  con- 
trolling and  indicating  devices  to  adapt  it  for  use  in  electric 
interlocking  and  the  following  parts  (specially  pertaining  to 
this  machine)  are  employed  for  the  purpose  of  controlling  the 
various  electrical  circuits  used  in  the  system :  Lock  slide,  con- 
nected directly  to  the  lever  by  a  pin,  and  indication  and 
safety  magnets  supported  on  the  magnet  girder ;  machine 
controller  and  terminals  mounted  on  a  slate  base,  the  contact 
slide  of  the  controller  being  connected  to  the  lever  by  a  bell 
crank  and  link ;  fuse  panel  below  machine  controllers  and 
accessible  independently  of  machine  controllers  which  are  en- 
closed and  locked  within  the  casing  surrounding  the  machine  ; 
solenoid  electric  lock,  the  plunger  of  which  engages  with  an 
extension  of  the  mechanical  locking  tappet ;  and  low  voltage 
circuit  controller,  connected  by  a  bell  crank  and  links  to  the 
end  of  the  rocker  as  shown  in  solid  lines,  or  by  a  link  directly 


locking  plate,  the  plunger  engaging  with  an  extension  piece 
attached  to  the  tappet,  which  extension  piece  also  has  two 
shallow  notches  with  beveled  sides  in  which  rests,  when  the 
tappet  is  in  either  the  normal  or  reverse  position,  a  short 
plunger  with  a  button  head.  The  raising  of  the  latch  of  the 
lever  will  operate  the  tappet  which  is  allowed  a  little  free 
motion  independent  of  the  position  of  the  plunger  of  the 
electric  lock.  This  free  motion  is  sufficient  to  raise  the  short 
button-head  plunger  and  cause  it  to  close  the  lock  circuit  at 
the  lock  by  forcing  an  insulated  metal  bar  into  contact  with 
two  springs,  when,  if  the  circuit  is  not  open  at  some  other 
point,  nor  shunted,  the  plunger  of  the  lock  will  be  withdrawn 
from  the  extension  piece  on  the  tappet  and  the  tappet  be 
left  free  to  be  further  moved  by  the  lever. 

The  low  voltage  circuit  controller  shown  in  detail  is  for 
the  control  of  the  low  voltage  track  circuits,  and  its  particular 
feature  is  the  threaded  sliding  rod  carrying  the  contact  wipers 
which  can  be  adjusted  to  any  required  position. 

The  mercury  time  release  depends  for  its  action  upon  a 
certain  quantity  of  mercury  being  thrown  by  the  movement 
of  the  lever  into  a  chamber  from  which,  upon  the  return 


Fig.    1920.     Federal    Electric    Interlocking    Machine. 


to  the  lever  as  shown  by  dotted  lines.  A  mercury  time  release 
is  also  shown  connected  by  link  to  the  tail  of  the  lever. 

The  lock  slide  moves  in  guides  on  the  magnet  girder  and  is 
kept  from  being  lifted  out  of  its  position  by  restraining  strips 
or  plates.  The  lock  slide  carries  two  square  dogs  free  to 
move  vertically,  but  held  in  their  raised  position  by  springs. 
The  tops  of  these  dogs  are  normally  above  the  top  of  the 
lock  slide  and  are  beveled  so  that  the  movement  of  the  lever 
and  with  it  the  lock  slide  in  either  direction  causes  the- 
beveled  parts  of  the  dogs  to  come  into  contact  with  the  re- 
straining strips  or  plates  which  force  the  dogs  into  their 
lower  position,  in  which  position  they  engage  with  raised  por- 
tions of  the  magnet  girder,  thus  restricting  the  movement  of 
the  lever  to  the  operating  positions  until  the  movement  of 
the  switch  has  been  completed ;  the  necessary  and  proper  con- 
tacts made  and  broken  ;  and  the  safeta-  and  indication  magnets 
have  by  their  action  raised  the  dogl  in  the^lock  slide  into 
their  normal  position  again. 

The  safety  and  indication  magnets  are  of  the  solenoid  type 
and  their  action  is  such  that  if  energized,  excepting  at  the 
proper  time  in  the  cycle  of  the  system,  the  lever  becomes 
locked  either  in  the  normal  or  reverse  position ;  or  is  re- 
stricted to  movement  between  the  operating  positions.  This 
locking  is  effected  by  the  head  of  the  magnet  engaging  with 
pins  on  the  side  of  the  lock  slide. 

The    solenoid    electric    lock    is    attached    to    the    mechanical 


of  the  lever  to  its  original  position,  the  mercury  can  only 
escape  through  a  restricted  channel,  the  size  of  the  channel 
being  adjustable  so  that  the  time  taken  for  the  return  of  the 
mercury  may  be  varied  from  10  seconds  to  two  minutes.  The 
return  of  the  mercury  to  its  original  position  re-establishes 
the  electrical  connection,  not  by  the  mercury  making  metallic 
contact  between  two  metal  points,  but  by  the  weight  of  the 
mercury  distending  a  suitable  diaphragm  which  forces  out  a 
plunger  until  contact  is  made  between  two  metal  springs.  This 
mercury  time  release  can  be  applied  on  any  machine  or  device 
capable  of  imparting  the  necessary  movement  for  transferring 
the  mercury  to  the  "time"  chamber. 

The  Federal  Signal  Co.'s  No.  4  switch  gear  consists  of  a  cast 
iron  case  containing  a  motor,  a  train  of  gears,  a  switch  and 
lock  movement,  operating  and  indicating  circuit  controllers 
and  a  dynamic  brake.  It  may  also  contain  the  equivalent  of  a 
switch  box,  but  so  operated  that  the  controlled  circuit  is  not 
made  until  the  switch  is  locked  in  the  desired  position. 

The  arrangement  and  operation  of  the  plungers  for  locking 
the  switch  are  such  that  the  switch  can  only  be  locked  in 
that  position  which  agrees  with  the  position  of  the  mechanism. 
This  is  accomplished  by  an  oscillating  connection  or  link  be- 
tween the  main  gear  and  the  locking  plunger  proper  and  which 
link  operates  the  latter.  This  link  has  on  its  underside  a 
projection  or  locking  dog  which  engages  in  one  or  other  of 
two  notches  in  the  upper  edge  of  the  lock  rod,  and  a*j  the 


248 


INTERLOCKING. 


Figs,  1921-1927 


Figs.    1921-1922.      Dwarf   Signal.      Federal   Signal   Company. 


Fig.   1923.     Federal   Flcctric  Interlocking   Machim 


Fig.    1924.     Motor    Dwarf 
Signals. 


Figs.    1925-1926.      Switch    Lock    Slide    with    Indication 
and  Safety  Magnets. 

end  of  the  link  carrying  the  locking  dog  oscillates  from  side 
to  side,  it  follows  that  the  lock  rod  must  be  moved  to  agree 
or  the  switch  cannot  be  locked. 

The  operating  and  indicating  ccntro'lers  are  of  the  slide- 
type  with  wipers  adjustable  as  to  position  and  are  given  (be 
necessary  movement  by  a  cam  en  the  main  gear. 

The  electro-mechanical  screw  hand  release  Illustrated  can 
be  adjusted  so  as  to  be  operated  in  varying  times  and  can  be 
fitted  with  one  to  four  pairs  of  contacts  controlling  a  corre- 
sponding number  of  circuits. 

The  deflecting  bar  illustrated  differs  from  others  in  that 
the  stand  is  made  in  two  separate  parts  which  allows  of  their 
being  used  in  multiple  for  any  angle,  the  bars  themselves 
being  bent  as  required. 


Fig.  1927.     Signal  Mechanism  in  Place. 


Figs.  1928-1929 


INTERLOCKING. 


249 


AMEFUC.VX    ELECTRIC    INTERLOCKING    MACHINE. 

Fig.  1928  shows  a  sectional  view  of  the  interlocking  machine 
made  by  the  American  Railway  Signal  Company.  In  the  figure 
tlio  lever  is  in  the  indicating  position.  The  locking  is  of  the 
Saxby  &  Fanner  type,  being  about  one-half  the  size  of  the 
standard  mechanical  locking.  All  working  parts  are  assembled 
on  the  outside  of  the  main  frame,  which  leaves  everything 
exposed  to  view,  and  allows  the  parts  to  be  easily  removed. 
The  contacts  are  designed  to  prevent  trouble  due  to  their  burn- 
ing on  a  small  arc.  All  breaks  are  quick  and  wide.  In  their 
normal  and  reversed  positions,  all  interlocking  levers  stand 


pulled  from  the  machine,  moving  the  controller  arm  42  to 
the  reverse  position  and  closing  the  reverse  circuit  to  the  op- 
erated unit,  the  driving  dog  sliding  through  the  driving  piece 
on  the  locking  bar,  and  the  shaft  sliding  through  the  crank  49. 
When  the  operated  unit  has  completed  its  movement,  the  In- 
dication, which  is  an  induced  current  from  an  induction  coil, 
jumps  the  gap  154-3,  and  closes  the  relay  points  96,  which  points 
close  the  circuit  4,  releasing  the  indication  latch  67  and  per- 
mitting the  solenoid  to  release  its  plunger.  This  final  upward 
movement  of  the  plunger  twists  the  lever  through  its  final 
movement,  completing  the  movement  of  the  locking  bars.  When 


Fig.     1928.      Electric     Interlocking     Ma- 


chine.     American    Railway    Signal 


the  plunger  is  Hearing  the  end  of  its  stroke,  the  pin  in  the 
controller  rod  engages  the  controller  arm  74,  and  opens  the 
circuit  for  the  completion  of  the  stroke. 

Pigs.  1937-1938  shows  the  induction  coil.  The  poles  of  the 
core  of  the  primary  winding  are  indicated  by  134,  the  armature 
of  the  interrupter,  131, — the  contact  points,  135, — and  the 
electro-magnet  for  blowing  out  the  spark  at  the  points,  142- 


nt    an    angle    of    about    15    deg.    from    the    vertical.      They    are 
latched    in    both    normal    and    reverse   positions. 

To  operate  the  machine,  the  lever  man  presses  the  latch  28, 
releasing  the  lever.  He  then  twists  the  lever  to  the  vertical 
position,  which  movement,  by  rotating  the  square  shaft  of  the 
lever,  moves  the  locking  bar  through  one-half  of  its  stroke  by 
means  of  the  driving  dog  25.  This  clog  is  engaged  in  a  driving 
piece,  which  is  riveted  and  brazed  to  the  bar.  The  rotation 
of  the  lever  shaft  also  turns  the  crank  40.  which  in  turn 
lifts  connecting  rod  51.  the  plunger  55,  and  the  controller 
rod  53.  When  the  lever  is  in  the  vertical  position,  the  indica- 
cation  latches  66  and  67  drop  into  place  and  prevent  further 
rotation  until  the  indication  is  received.  The  lever  is  then 


Fig.    1929.      Concrete    Interlocking    Tower    for    Ameri- 
can   Electric    Interlocking   Plant. 

These   coils   are   housed   in   the    cases,   as   shown,   or   are   put   in 
the   signal    cases. 

Fig.  1939  shows  the  switch  machine.  The  operation  of  this 
machine  is  as  follows :  When  current  is  supplied  to  the  con- 
trol wires,  part  of  it  passes  through  the  pole  changer  box  con- 


250 


INTERLOCKING. 


1930-1940 


Fig.   1930.     Switch   Machine   and  Derail  in   Service.     American  Electric  Interlocking. 


£1-130 


Fig.   1931-1932.     High  Voltage  Induction  Coil   for  Electric  Interlocking. 


Figs.    1933-1940.     American    Model   B   Switch    Machine. 


Figs.  1941-1945 


INTERLOCKING. 


251 


Fig.   1941.     American  Dwarf  Signal  at  Electric  Interlocking  Plant. 

c 


I  rir  -  -  iT- - --V -"--iM  Lr.— -•^---VT-^ 


•---J 


.J 


Figs.  1942-1943.    Relays  Used  with  Electric  Interlocking,  American  Railway  Signal  Company. 


Fig.    1944.     Solenoid    Dwarf    Signal. 


Fig.    1945.     Hayes    Derail    and    Switch    Movement    in 
Service.     American    Electric    Interlocking. 


252 


INTERLOCKING. 


Figs.  1946-1951 


Figs.    1946-1947.     Motor    Dwarf    Signal    Mechanism.      American    Railway  Signal  Company. 


Figs.   1948-1949.     Electric  Dwarf  Signal   (See   Figs.    1946-1947.)     American  Railway  Signal   Company. 


Figs.    1950-1951.     Electric          Dwarf  Signal   Mechanism 

(See  Figs.   1946-1949).!^  American  Railway  Signal  Company 


Figs.  1952-1953 


INTERLOCKING. 


253 


tacts  69,  and  through  the  motor  in  the  right  direction  for 
the  rotation  required  for  the  switch  movement.  Another  part 
of  the  current  passes  through  the  pole  changer  coils  53, 
which  coils  control  the  pole  changer  box  contacts.  Still  another 
part  of  the  current  passes  through  the  coil  of  the  clutch  34. 


points  to  move  over  (see  Fig.  1941).  When  the  switchpoints  are 
clear  over,  the  second  slope  on  the  cam  52  again  engages 
the  pin  in  the  lever  arm  94  and  moves  the  detector  bar  the 
remaining  distance,  also  moving  the  plate  31  and  causing  the 
opposite  bolt  to  enter  the  lock  rod.  The  circuit  controller  box 


54-Lever   Electric   Interlocking   Machine   Installed  by 
American  Railway  Signal  Company. 


ie  current  through  this  clutch  causes  the  motor  shafts  108 
to  be  engaged  with  the  operating  shaft  80,  through  the  gear 
set  18-19-44,  and  the  turning  of  the  motor  rotates  this  operating 
shaft.  The  movement  of  the  shaft  80  turns  the  cam  52,  and  the 
first  movement  of  the  cam  engages  the  pin  97  of  the  lever 


controls  the   indication  circuit,   the   clutch   circuit  and   also  the 
circuits  of  the  signal  governing  over  the  switch.    This  machine 
is  so  designed  that  it  can  be  placed  on  the  ties  without  cutting 
or   framing  any    of   them. 
Fig.    1953  shows  the  clutch  brake  and  gear  set.     The  clutch 


arm  94  and   moves   it  to   its   center   position,   where   it   remains       coil  34    (Fig.  1939)   is  stationary,  and,  when  energized,  attracts 


Fig.    1953.     Clutch    Magnet. 


until  the  switch  point  has  moved  its  full  stroke.  This  lever 
arm  94  controls  the  detector  bar,  which  is  connected  to  the 
outer  hole  in  the  arm,  moving  the  bar  half  way.  The  lever 
arm  94  also  controls  the  plate  31,  which  carries  the  locking 
bolts  29.  This  locking  plate  moves  one-half  its  stroke,  with- 
drawing one  bolt  from  the  lock  rod  and  setting  the  other  bolt 
close  to  the  rod  ready  for  it  to  lock  in  the  other  position. 
When  the  locking  bolts  are  withdrawn,  the  teeth  in  pinion  23 
engage  with  the  teeth  in  the  rack  85  and  cause  the  switch- 


the  armature  35.  The  armature  carries  with  it,  through  the 
springs  107,  the  disc  36,  which  drives  the  cone  32  into  the  shell 
this  shell  being  keyed  to  the  motor  shaft.  The  cone  32  is 
keyed  to  the  shaft  of  the  gear  set  and,  when  the  motor  is 
turning  with  the  clutch  energized,  drives  the  gear  set  through 
the  cone  and  its  shell.  Shaft  80  is  the  main  operating  shaft. 
The  rear  of  the  clutch  cone  32  carries  another  cone  which  is 
driven  into  the  stationary  shell  26  when  the  machine  is  sta- 
tionary, this  preventing  any  possibility  of  the  machine  being 


254 


INTERLOCKING. 


Figs.  1954-1955 


operated   by   external   means.     The  small   spring   serves   to   ad- 
just the  tension  on  the  clutch. 

The   relay,   Fig.    1942,   is  used   In   the  operation   of  a   signal. 
The   normal    position    is,    as   shown,    with    both   front   and   back 


lever  in  the  reverse  position  through  one  finger  of  the  relay 
to  the  signal  and  back  to  the  lever  again  through  the  other 
finger.  When  the  signal  is  returning  to  the  stop  position,  an- 
other coil  is  energized  and  de-energized,  raising  and  dropping 


Fig.   1954.     Motor  for  American   Signal   Mechanism. 


contacts  open.  To  operate  the  signal,  the  coil  is  first  energized 
and  then  de-energized  by  the  movement  of  the  lever  in  the  in- 
terlocking machine.  This  causes  a  plunger  to  be  raised  and 
dropped.  The  dropping  of  the  plunger  moves  the  armature  into 
contact  with  the  front  points.  Current  then  flows  from  the 


another  plunger  which  moves  the  armature  fingers  into  contact 
with  the  back  points,  through  which  position  of  the  armature 
the  indication  is  received  after  the  signal  has  gone  to  stop. 
After  the  indication  is  completed,  the  armature  fingers  return 
to  the  neutral  position. 


ELECTRO-PNEUMATIC  INTERLOCKING 


THE    UNION    ELECTRO-PNEUMATIC    INTERLOCKING. 

In  this  system  of  interlocking,  the  operating  power  Is 
supplied  by  means  of  air  compressed  at  some  convenient  point, 
stored  in  one  or  more  reservoirs  and  conveyed  to  each  func- 
tion by  suitable  pipe  and  hose  connections.  The  control  of 
this  power  is  effected  by  means  of  electromagnets,  the  necessary 
electric  current  being  obtained  from  any  reliable  source,  such 
as  primary  or  storage  batteries  or  from  a  generator. 

The  ordinary  air  pressure  used  is  70  Ibs.  per  sq.  in.,  al- 
though the  standard  design  of  apparatus  can  be  made  to  work 
satisfactorily  with  any  pressure  between  50  and  100  Ibs. 
In  order  to  avoid  trouble  from  moisture  condensing  and 


signal  pest  or  to  the  ties  near  the  switch  as  the  case  m:iy  be. 
Near  each  cylinder  is  a  small  auxiliary  reservoir  to  provide  a 
sufficient  supply  of  air  to  insure  quick  action  of  the  piston  at 
every  operation. 

The  admission  and  exhaust  of  air  at  the  cylinder  is  governed 
by  electromagnetic  valves,  controlled  through  wires  from  the 
interlocking  machine. 

In  the  machine  (Figs.  1955-1967)  the  levers  are  only  a  few 
inches  long  and  very  light,  their  principal  work  being  to  open 
and  close  electric  circuits,  and  to  operate  the  necessary  me- 
chanical locking  between  each  other. 

These   levers    appear  as   cranks   on   the  front  of   the  machine. 


Fig-  J955-     The  Electro-Pneumatic  Interlocking  Machine,  Horizontal  Roller  Type. 


freezing  in  the  small  air  passages,  the  air  on  leaving  the 
compressor  is  passed  through  a  condenser  consisting  of  a  number 
of  cooling  pipes  (see  Fig.  2938)  and  a  large  percentage  of  the 
moisture  is  removed.  Any  remaining  moisture  is  neutralized 
by  alcohol,  which  is  placed  in  the  pipes  and  reservoir  in 
freezing  weather. 

The  air  pressure  acts  on  the  piston  of  a  -cylinder  fixed  to  the 


Each  lever  has  a  latch  by  which  it  Is  held  in  any  desired 
position,  but  this  latch  has  nothing  to  do  with  the  interlocking 
of  one  lever  with  another.  Instead  of  pulling  or  pushing  a 
lever  the  signalman  turns  it  to  the  right  or  left,  and  operates 
a  horizontal  shaft  which  revolves  on  its  axis  through  an  arc 
of  60  deg.  The  shaft  by  means  of  a  rack  and  pinion  actuates 
miniature  Saxby  &  Farmer  locking,  differing  from  that  shown 


Fig.  1956 


INTERLOCKING. 


255 


iu  Figs.  665-716  only  in  size  and  in  the  provision  made  for 
the  movement  of  signal  levers  either  to  the  right  or  to  the  left 
of  the  normal  position. 

The  "indication"  from  a  switch  or  signal  actuates  the 
armature  of  an  electromagnet  fixed  in  the  machine,  this  arma- 
ture engaging  with  suitable  notches  in  a  segment  attached  to 
the  shaft  of  the  lever.  As  arranged  with  switch  levers,  this 
magnet  when  de-energized  locks  the  shaft  after  it  has  been 
turned  far  enough  to  move  the  switch,  and  prevents  the 
signalman  from  completing  the  stroke  of  the  lever  until  the 
switch  has  finished  its  movement  and  is  locked  in  the  new 
position.  The  indication  being  received,  the  stroke  of  the 
lever  may  be  completed  and  (the  necessary  locking  having 
thereby  been  released)  the  lever  for  the  signal,  giving  a  right 
to  proceed  over  this  switch,  may  be  reversed. 

To    make    clear    the   general    principles    governing    switch    and 


to  clear  in  response  to  its  lever,  but  this  is  not  considered 
necessary  on  account  of  the  comparatively  insignificant  results 
of  such  a  failure.  The  double  reverse  movement  of  the  signal 
levers,  besides  forming  a  means  of  selecting  and  operating 
signals  also  provides  within  itself  an  effective  form  of  locking 
between  two  conflicting  signals,  since  one  lever  cannot  assume 
two  positions  at  the  same  time. 

In  adapting  the  signal  lever  to  the  control  of  the  four  signals 
arranged,  as  "shown  in  Fig.  1971,  the  wires  operating  the  two 
opposing  signals  of  Figs.  1968-1970  would  be  passed  through  a 
circuit  controller  or  selector  operated  by  the  switch  lever  or 
by  the  switch  itself,  so  that  the  direction  of  traffic  would  still 
remain  under  the  control  of  the  signal  lever,  but  the  signal 
operated  for  the  route  of  a  direction  so  selected  would  be 
determined  by  the  position  occupied  by  the  switch  at  the  time. 
This  arrangement  would  necessitate  extending  the  circuit  of 


Fig.  1956.     Cabin  "A"  Machine.     P.  T.  &  T.  New  York    City.     Union  Switch  &  Signal   Company. 


signal  operation,  Figs.  1968-1975  are  presented.  The  operation 
of  a  signal  will  first  be  described.  Fig.  1968  shows  an  ordinary 
lever  of  a  mechanical  type  arranged  to  stand  normally  on 
center,  which  has  attached  to  it  a  circuit  controller  that 
closes  a  circuit  operating  one  signal  when  moved  to  the  left, 
and  closes  a  similar  circuit  for  a  second  signal  (conflicting  iu 
function  with  the  first)  when  moved  to  the  right.  When  the 
lever  is  normal,  both  signals  are  in  the  stop  position  and  the 
lever  is  not  engaged  by  the  electric  lock.  When  the  lever  is 
reversed  to  clear  a  signal,  the  latter,  on  leaving  the  stop 
position,  opens  the  circuit  controlling  the  lock  which  immedi- 
ately engages  the  lever  and  prevents  its  complete  return  t<> 
normal,  as  illustrated  in  Fig.  1970.  However,  the  lock  permits 
of  a  partial  return  of  the  lever  to  normal  (Fig.  1969),  an 
amount  insufficient  to  release  such  mechanical  locking  as  is 
operated  by  it  (not  shown),  and  which  must  remain  effective 
until  the  signal  is  actually  in  the  stop  position.  This  partial 
movement  of  the  lever  toward  normal  cuts  off  the  current 
holding  the  signal  in  the  proceed  position  and  permits  its 
return  by  gravity  to  the  stop  position.  If  for  any  reason  it 
should  fail  to  do  so,  it  is  obvious  that  the  lever  would  be 
prevented  from  being  put  normal,  and  hence  a  change  of  route 
from  the  one  governed  by  the  deranged  signal  is  prevented. 
A  second  lock  similarly  controlled  by  the  signal  in  its  extreme 
clear  position  might  bo  added  to  detect  failures  of  the  signal 


the  signal  lever  lock  to  the  control  of  the  two  additional  sig- 
nals, so  that  any  one  of  the  four  being  operated  would  produce 
the  same  effect  on  the  lock  as  would  either  of  the  two  signals 
of  the  arrangement  shown  in  Figs.  1968-1970.  This  extension 
of  the  lock  circuits  is  omitted  from  Fig.  1971  in  order  that' 
the  controlling  circuit  may  be  better  understood.  If  we 
introduce  other  tracks  and  switches,  and  the  necessary  signals 
to  govern  movements  from  them  over  the  switch  shown  In 
Fig.  1971,  an  extension  of  the  selecting  method  may  be  made 
to  Include  the  operation  from  the  same  lever  of  all  signals 
involved ;  but  on  condition  that  the  track  and  traffic  conditions 
never  require  but  one  signal  to  be  operated  at  a  time.  When 
two  or  more  signals  may  be  operated  simultaneously  they,  of 
course,  require  the  use  of  as  many  levers.  Figs.  1972-1975 
show  diagrammatically  the  arrangement  of  circuits  and  ap 
pnratus  used  for  operating  switches.  The  normal  position  of 
the  lever  is  at  the  extreme  left,  as  shown  in  Fig.  1972.  The 
circuit  controller  C-N-L-R  controls  the  circuits  affecting  the 
switch  valve  magnets,  and  normally  current  energizes  valve 
magnet  N,  the  other  two  magnets  being  de-energized.  The 
effect  of  this  condition  is  to  retain  air  pressure  against  the 
side  of  the  piston  which  holds  the  switch  in  its  normal  position. 
The  armatures  of  the  indication  magnets  N  and  R  permit  a 
partial  movement  of  the  lever  from  normal  to  reverse  (that  is, 
sufficient  to  shift  the  current  from  valve  magnet  N  to  valve 


256 


INTERLOCKING. 


Fig-  1957 


magnets  L  and  R),  as  indicated  by  dotted  lines  in  Fig.  1972, 
the  effect  of  which  is  to  de-energize  the  former  and  to  energize 
both  of  the  latter.  Valve  magnet  L  (known  as  the  lock 
magnet)  is  energized  at  the  beginning  of  the  stroke  and  before 
current  is  removed  from  N  ;  this  withdraws  the  lock  controlled 
by  magnet  L  which  holds  the  switch  valve  in  its  normal 
position.  The  de-energizing  of  N  and  the  energizing  of  magnet 
R  follow  immediately.  This  moves  the  "D-valve"  (19,  Fig. 
2021),  allows  the  air  to  escape  from  the  normal  side  of  the 
piston  and  admits  air  from  the  reservoir  on  the  reverse  side 
of  the  piston,  moving  it  to  the  other  end  of  the  cylinder  and 
reversing  the  switch.  This  partial  reversal  of  the  lever  can 
(through  the  usual  mechanical  locking  provided  between  switch 
and  signal  levers)  be  made  only  when  all  signals,  governing 
movements  over  the  switch  to  be  operated,  are  in  the  stop 


comes  locked  in  its  reversed  position  ;  current  is  also  cut  off 
from  the  indication  magnet  it  and  its  latch  released. 

Under  the  tappet  engaged  by  the  latches  of  the  indication 
magnets  is  shown  a  circuit  shifter,  known  as  the  "quick 
switch,"  controlling  these  magnets.  It  is  moved  by  the  tappet 
only  after  the  latter  has  been  released  and  after  the  lever  has 
been  put  into  one  or  the  other  of  its  extreme  positions.  This 
arrangement  is  designed  to  prevent  any  other  than  that  magnet 
which  corresponds  with  the  position  of  the  switch  desired  being 
in  circuit  at  any  time  (a  precaution  designed  to  guard  against 
false  indications  resulting  when  the  switch  is  momentarily  in 
one  position  and  the  lever  is  in  a  semi-reversed  position  tending 
to  shift  it  to  the  other.) 

The  same  conditions  govern  the  return  of  the  switch  and  its 
lever  to  normal  ;  but  the  other  pair  of  indication  contacts,  N 


Pig.     1957.     Electro-Pneumatic     Interlocking    Machine;  View  from  Front  Showing  Lockinj 

and  Indication  Segments. 


Combination  Plate 


position  and  when  so  moved  it  retains  locked  all  such  signals 
•  until  its  complete  reversal  is  effected.  Mounted  over  the  switch 
and  lock  movement  are  two  paiys  of  contact  springs  so  arranged 
that  one  pair  is  closed  by  the  slide  bar  in  its  extreme  normal 
position  (Fig.  1972)  and  the  other  pair  closed  in  its  extreme 
reverse  position  (Fig.  1973).  Both  pairs  of  these  contacts  are 
open  unless  the  switch  is  locked  in  either  one  position  or  the 
other.  When  the  complete  movement  of  the  switch  is  effected 
and  the  lock  of  the  switch  movement  has  secured  the  switch 
in  its  reversed  position,  the  plate  P  is  shifted  by  the  move- 
ment into  contact  with  springs,  R,  R.  The  effect  of  the  circuit 
thus  established  on  the  indication  magnet  R  at  the  machine 
(which  circuit  is  formed  in  part  by  the  wire  extending  from 
the  machine  to  the  lock  magnet  L,  largely  for  the  sake  of 
economy  in  wires  and  for  convenience  of  arrangement)  is  to 
energize  this  magnet,  and  thereby  to  lift  its  armature  from 
longer  obstructing  the  movement  of  the  lever  to  its  extreme 
reversed  position  (Fig.  1973).  The  final  movement  of  the 
lever  may  then  be  made,  which  releases  the  mechanical  locking 
that  was  heretofore  in  effect,  preventing  signals  from  being 
cleared  for  movements  over  the  switch,  and  at  the  same  time 
shifts  the  switch  controlling  contacts  to  the  position  shown  in 
Fig.  1974,  the  effect  of  which  is  to  remove  at  once  the  current 
from  the  valve  lock  magnet,  whereupon  the  switch  valve  be- 


and  N,  on  the  switch  movement,  and  the  other  indication 
magnet,  N,  engaging  the  lever,  are  brought  into  use  for  this 
purpose.  When  more  than  one  switch  is  operated  by  a  single 
lever,  as  in  the  case  of  a  cross-over,  the  normal  and  reverse 
valve  magnets  at  one  switch  are  in  series  with  their  correspond- 
ing magnets  at  the  other  switch,  the  lock  magnets  are  in 
multiple,  and  the  indication  contacts  in  series,  as  shown  in 
Fig.  1971,  an  extension  of  the  selecting  method  may  be  made 
of  the  two  contacts  thus  included  in  the  indication  circuit 
closes  as  its  own  switch  becomes  fully  moved  and  locked 
(this  being  the  case  whether  these  operations  occur  simultane- 
ously or  not),  but  no  indication  will  be  received  at  the  ma- 
chine unless  both  switches  are  locked  in  the  desired  position. 

The  signal  used  is  a  semaphore,  Figs.  1980-1981,  the  design 
being  the  same  used  both  for  interlocking  and  for  block  sig- 
naling, and  is  shown  in  Figs.  594-600.  Figs.  1978-1979  show 
a  mechanism  designed  to  operate  two  arms  in  three  positions, 
and  one  arm  in  two  positions.  The  arrangement  shown  is  for 
use  on  a  signal  bridge  where  the  two-position  arm  is  below  the 
mechanism  and  operated  by  the  rod  extending  downward.  The 
three-position  arms  are  situated  above  the  mechanism  and 
operated  by  the  rods  extending  upward,  one  for  each  arm. 
Each  of  these  rods  is  provided  with  two  cylinders,  as  may  be 
seen  in  Fig.  1978.  When  air  is  admitted  to  one  cylinder  its 


Figs.  1958-1959 


INTERLOCKING. 


257 


piston  is  raised,  raising  one  rack  which  moves  a  pinion  through 
half  its  travel  in  the  same  manner  as  with  the  three-position 
Style  "B"  motor  signal  shown  in  Fig.  538,  causing  the  arm 
to  assume  its  intermediate  or  "caution"  position.  When  the 
second  piston  is  raised  the  pinion  is  again  moved  upward, 
completing  the  movement  of  the  arm  to  the  clear  position.  The 


arm  to  the  stop  position  is  secured  by  the  use  of  the  spring 
8,  instead  of  by  a  weight  such  as  is  used  in  the  high  sema- 
phore. The  cylinder  is  movable  and  the  piston  stationary,  the 
air  pressure  pushing  up  the  cylinder  against  the  downward 
pressure  of  the  spring.  This  movement  causes  the  arm  to 
assume  the  clear  position,  and  on  the  release  of  the  air,  when 


Fig.    1958.     Electro-Pneumatic    Interlocking    Machine,    Horizontal    Roller  Type;  View  Showing  Side  Elevation. 


Fig.    1959.     Electro-Pneumatic 


Interlocking    Machine;    View    from    Rear 
and  Indication  Segments. 


Showing  Locking,   Combination  Plate 


mechanism  may  be  provided  with  special  piping  so  that  the 
air  supply  for  the  third  position  passes  through  the  second 
position  valve.  Circuit  controllers  attached  to  hard  rubber 
cylinders  may  be  seen- at  each  side  of  the  mechanism  in  Pig. 
1978. 

In  the  dwarf  semaphore    (Figs.   1985-1986)   the  return  of  the 


the  signal  is  to  be  restored  to  the  stop  position,  the  spring 
forces  the  cylinder  and  connecting  rod  downward.  The  piston 
rod  is  hollow,  thus  serving  as  a  port  for  the  admission  of  air 
to  the  cylinder  and  also  for  exhaust.  If  the  spring  should 
fail  to  restore  the  signal  to  the  stop  position,  the  signal  lever 
would  be  held  by  the  indication  lock,  preventing  its  full  return 


258 


INTERLOCKING. 


Figs.  1960-1961 


fVffvr* 


Fig.   1960.     Electro-Pneumatic  Interlocking  Machine;  Rear  View  of  Track  Model. 


^ 

f. 

1                    II 

4 

IBE        TERMINAL          BOARDS 


D 


Fig.     1961.     Electro-Pneumatic    Interlocking    Machine;     Front    Elevation    Partly  in  Section. 


Figs.  1962-1967 


INTERLOCKING. 


259 


-  QUAOPUKT 

SIGNAL  LEVER 


Fig.  1962.     Section  Through  Signal  Lever. 


OFUVIBTO  s«»rr 


:ONT  OF  M»CHINE  FRAME 


Fig.   1963.     Section  Through  Switch  Lever. 


Figs.    1962-1963.     Sectional   Views   of   Electro-Pneumatic   Interlocking  Machine. 


Fig.    1964.     Indication    Segment 
for    Switch    Lever. 


Fig.    1965.     Indication    Segment 

for      Switch      Lever,      with 

Electric    Detector 

Circuits. 


Fig.    1966.     Indication    Segment 
for  Signal  Lever. 


Fig.    1967.     Indication    Segment 

for     Traffic     Lever     (Check 

Locking). 


to  the  normal  position,  thus  compelling  attention  to  the  defect       attached   to  the  cylinder.     Thus   the  indication   circuit  is  open 

In   the  signal.     The  Indication  contacts  are  closed   by  a   metal       unless  the  arm  is  in  the  stop  position. 

strip    (27,    Fig.    1986)    mounted   on  an   Insulated   contact   block  Figs.    1995-1996    show   a   suspended   semaphore   arm   operated 


260 


INTERLOCKING. 


Figs.  1968-1972 


CLCCTItIC  'SCLKnit' (aKUIT  SHIFTtf) 

conntou/ne  USUAL  UASHCJS. 


Fig.   1968.     Signal   Lever  in   Normal   Position;   Sig- 
nals at  Stop;  Lever  Free  to  Clear  Either  Signal. 


Fig.  1969.     Signal  Lever  Reversed  to  the  Left;  One 
Signal   at   Proceed;   Signal  Lever   Locked,   Pre- 
venting Full  Movement  to  Normal. 


Fig.     1971.     Track     and     Signal     Layout; 
Selected   Signals. 


by  a  cylinder  situated  above.  This  is  the  standard  arrange- 
ment for  route  signals  on  some  roads.  It  is  also  convenient 
for  use  as  a  starting  signal  from  terminal  train  sheds,  where 
It  may  be  attached  to  ..the  building  above  the  track. 

Fig.    1997   shows  a  rotary  pot  signal   designed   to   be   placed 
between  tracks  where  there  is  very  little^.clearance ;  the  cylinder 


Fig.    1970.     Signal 

Position.     Signals  at  Stop 


"Half-Reverse" 
Lever  Free  to 


Complete    Movement   to    Normal. 


Fig.    1972.     Switch   Lever   in   Normal   Position;   Dotted   Lines   Show 

Preliminary  Movement  Made  by  Lever  in  Reversing  the  Switch; 

Switch  Has  Not  Started  to  Move. 


Figs.  1973-1975 


INTERLOCKING. 


261 


Is  placed  in  a  horizontal  position  and  moves  the  lamp  and  disks 
by  a  crank.  They  are  restored  to  the  stop  position  by  the 
spring  operating  under  the  same  conditions  as  In  the  dwarf 
signal. 

Portions  of  the  electro-pneumatic  interlocking  machine  are 
shown  in  Figs.  1957-1967,  Figs.  1962-1963  being  a  section  from 
back  to  front.  The  track  model,  a  feature  of  this  machine, 
appears  in  section  in  the  upper  part  of  Figs.  1961  and  1965. 


locking  parts,  supported  by  the  locking  bar  brackets,  are 
similar  in  design  to  the  interlocking  shown  in  Figs.  794-845. 
The  whole  apparatus  is  inclosed  in  a  wooden  case  with  glass 
top.  The  wire  connections  (not  shown  in  the  drawings),  are 
all  run  to  binding  posts  on  the  rear  of  the  frame  supporting 
the  machine. 

The  process  of  operating  a   switch   lever   may   be   briefly  de- 
scribed as  follows,  taking,  for  example,  lever  No.  3,  Fig.   1961. 


Fig-    1973-     Switch    Lever    Against    Re- 
verse  Indication    Stop;    Switch    Has 
Moved   and    Become    Locked   in 
Reverse   Position;   Lever   Has 
Been    Released    by    Indica- 
tion     Lock     for     Final 
Movement    to    Full    Re- 
verse  Position. 


<ig.     1974.     Switch     Lever     in     Reverse 
Position;      Indication      Latch      Re- 
leased; "Quick  Switch"  in  Posi- 
tion to   Receive   Normal 
Indication. 


a  i     ;«C/C«T/O/V  CIRCUITS 

NETS . of--/ ' 


Fig-    1975-     Switch    Lever    and    Con- 
nections    Arranged     to     Operate 
a  Crossover. 


It  consists  of  metal  strips  representing  a  plan  of  the  track. 
Each  portion  which  represents  a  switch  is  movable,  and  is 
connected  to  the  switch  levers  in  such  a  way  that  every 
movement  of  the  lever  to  move  a  switch  in  the  track  moves 
the  corresponding  part  of  the  model  (see  Fig.  1960).  Some 
models  have  miniature  signals  as  well  as  tracks. 

The  principal  parts  of  the  interlocking  machine  are  indicated 
in    the    transverse    section.    Fig.    1961.      The    mechanical    inter- 


All  signals  which  could  give  a  clear  route  over  the  switch  In 
its  present  position  being  in  the  stop  position,  so  that  the 
interlocking  will  not  interfere  with  the  intended  movement, 
the  signalman  moves  the  lever  to  the  right,  revolving  the 
shaft.  As  soon  as  this  revolution  has  begun  the  driver  on  th« 
shaft  (see  Figs.  1962-1963)  has  moved  the  locking  bar  a  short 
distance,  so  as  to  lock  all  levers  which,  if  moved,  would  permit 
trains  to  interfere  with  the  intended  movement.  This  locking 


262 


INTERLOCKING. 


Figs.  1976-1979 


SECTIONAL  SIDE  VIEW 


Figs.    1976-1977.     Electro-Pneumatic   Switch   Valve    Mounted   Independent  of  Cylinder. 


Figs.    1978-1979.     Electro-Pneumatic    Signal    Mechanism  for    Operating  Two    Arms    Above    in   Three    Positions, 
and    One   Arm   Below   in   Two    Positions.      Pennsylvania   Railroad. 


Figs.  1980-1984 


INTERLOCKING. 


263 


effected,  the  further  revolution  of  the  shaft  causes  bronze 
strips  to  close  the  switch  valve  circuits,  which  admit  air  to 
the  switch  cylinder.  The  piston  movement  produced  by  this 
air  pressure  unlocks  the  switch,  moves  it  to  the  other  position, 
and  then  locks  it.  The  locking  of  the  switch  having  been 
completed,  the  closing  of  the  contact  in  the  indication  boi 
energizes  its  proper  indication  magnet  in  the  machine,  and  the 
signalman  is  then  able  to  complete  the  stroke  of  his  lever, 
leaving  it  inclined  to  the  right.  This  final  movement  pushes 
the  locking  bar  the  remainder  of  its  stroke  and  unlocks  the 
lever  or  levers  by  which  the  signalman  will  clear  the  signal  to 
permit  a  train  to  pass  over  the  switch  in  its  new  position. 


desired.  The  principal  parts  are  so  lettered  as  to  explain  their 
use.  The  flexible  connection  from  the  auxiliary  reservoir  to 
the  cylinder  is  employed  to  provide  against  undue  strain  on 
the  pipe  connections  on  account  of  settling  of  the  different 
parts.  The  piston  rod  and  the  slide  bar  of  the  switch  and 
lock  movement,  together  with  the  detector  bar  connection, 
are  permanently  connected  and  may  be  treated  as  a  single 
rod.  This  rod  has  a  stroke  of  eight  in. ;  but  its  action  on 
the  switch,  by  means  of  the  escapement  crank,  does  not  begin 
until  it  has  moved  about  two  in.  ;  and  the  switch  action  is 
finished  in  the  next  four  in.  of  the  movement ;  so  that  the 
first  two  in.  can  be  used  to  unlock  the  switch  and  the  last 


L 


Figs.    1980-1981.     Three-Arm   Electro- 
Pneumatic    Signal.      Pennsylvania 
Railroad. 

The  switch  cylinder  is  shown  in  Fig.  1999.  Each  cylinder, 
by  means  of  its  piston,  moves  the  switch,  detector  bar  and 
lock ;  also  two  or  more  switches  near  together  may  be  moved 
by  the  same  cylinder  where  it  is  found  desirable  to  do  so  (see 
Fig.  1998).  This  multiplication  of  functions  is  provided  for 
by  an  increase  in  the  size  of  the  cylinder  or  by  a  higher  air 
pressure. 

In  Figs.  1998-1999  and  2017-2019  is  shown  the  movement 
by  which  the  rod  from  the  cylinder  performs  the  double  func- 
tion of  moving  the  switch  and  locking  it.  This  device  is  similar 
In  principle  to  the  locking  apparatus  used  with  other  kinds 
of  Interlocking  where  such  a  combination  of  functions  \*. 


Fig.    1982.     Hudson  &  Manhattan   Interlocking  Tower 
in    Church   Street  Terminal. 

two  in.  to  lock  it  in  its  new  position.  The  lock  rod,  where  It 
passes  through  the  frame,  appears  in  elevation,  as  in  Fig. 
2020.  The  slide  unlocks  the  switch  by  withdrawing  a  lug  from 
the  lower  notch  ?/  (which  lug  is  indicated  in  Fig.  2017  by 
dotted  lines),  and  locks  the  switch  after  moving  it  (and 
changing  the  position  of  the  lock  rod)  by  pushing  another  lug 
into  the  upper  notch  x.  The  vertical  pin  in  the  slide  bar  which 
moves  the  escapement  crank  is  fitted  with  a  loose  collar. 

Figs.  2021-2022  show  the  details  of  the  switch  valve.  The 
admission  and  exhaust  of  air  to  and  from  the  cylinder  is  con- 
trolled by  the  D-valve  19,  in  the  same  manner  as  is  done  by 
the  ordinary  slide  valve  of  a  steam  engine.  This  valve  is 
operated  by  two  small  pistons,  one  on  each  side,  which  are  in 


Fig.    1983-1984.     Three-Position    Electro-Pneumatic 

Dwarf   Signal.     Upper   Quadrant   Indication, 

Having  One  Cylinder  for  Each  Position. 

turn  controlled  by  the  pin  valves  of  the  normal  and  reverse 
magnets,  the  same  as  in  the  signal  mechanism,  explained  In 
connection  with  Fig.  597.  The  lock  magnet  in  the  center  con- 
trols a  bolt  which  engages  the  D-valve  in  each  of  its  extreme 
positions.  AVhen  the  magnet  is  energized  the  spring  16  Is 
compressed  and  the  bolt  withdrawn,  allowing  the  D-valve  to 
be  moved.  Thus  it  is  necessary  to  have  one  magnet  de- 
energized  and  the  other  two  energized  before  the  switch  will 
be  moved. 

For  the  Subway  Division  of  the  Interborough  Rapid  Transit 
Co.,  owing  to  the  restricted  clearances,  it  was  found  nec- 
essary to  redesign  some  of  the  electro-pneumatic  interlock- 
ing apparatus.  It  was  necessary  to  mount  the  controlling  valv« 
magnets  for  the  switch  cylinders  on  the  cylinder  head  and 
nlso  to  design  a  motion  plate  switch  and  lock  movement.  In 
some  cases,  also,  the  switch  valves  were  mounted  on  a  separata 
base  several  feet  away  from  the  cylinder.  The  special  switch 


264 


INTERLOCKING. 


Figs.  1985-1988 


12 


18 


Figs.  1985-1986.     One-Arm  Electro-Pneumatic  Dwarf  Signal. 


Names     of     Parts     of     One-Arm 
Electro-Pneumatic  Dwarf  Sig- 
nal; Figs.  1985-1986. 

1  Post  and  Base 

2  Inside  Plug  for  Opening  for  Me- 

chanical   Connection 

3  Outside    Plug    for    Opening    for 

Mechanical  Connection 

4  Mechanism  Cover 

6  Up  and  Down  Rod 

7  Bottom  Spring  Socket 

8  Restoring  Spring 

9  Top  Spring  Socket 

10  Semaphore    Bearing 

11  Semaphore  Crank 

12  Spectacle,  60° 

13  Blade 

14  Semaphore  Shaft 

15  Journal  for  14 

1 6  Cap 

17  Lamp  Bracket 

18  Back  Spectacle 

19  Cylinder 

20  Nut   for  Fastening  Piston   Ring 

Cage 

21  Cage  for  Piston  Rings 

22  Piston 

23  Hollow    Piston     Rod    and    Air 

Inlet 

Cylinder  Cap 
Valve  Base 
Circuit     Breaker     Springs     and 

Base 

Contact  Block  and  Strip 
Bolt  for  2  and  3 
Hole  for  Crank  Pin 
Doivel  Pins 
Cap  Screw 

Semaphore  Adjusting  Screzv 
Tap  Bolt 
Screzv  for  Cap 
Pin  Valve  Magnet 


Name      of      Parts      of      Two-Arm 
Electro-Pneumatic  Dwarf  Sig- 
nal; Figs.  1987-1988. 

Post  and  Base 

Cap  for  Lower  Semaphore  Bear- 
ing 

Semaphore  Bearing 

Cap  for  Upper  Semaphore  Bear- 
ing 

Mechanism  Cover 

Up  and  Down  Rod,  Lower  Arm 

Up  and  Down  Rod,  Upper  Ann 

Spectacle,  60° 

Blade 

Semaphore  Shaft,   Upper  Arm 

Semaphore  Shaft,  Lower  Arm 

Back  Spectacle 

Semaphore  Crank 

Lamp  Bracket 

Restoring  Spring 

Top  Spring  Socket 

Bottom  Spring  Socket 


Figs.    1987-1988.     Two-Arm    Electro-Pneumatic   Dwarf   Signal. 


Figs.  1989-1994 


INTERLOCKING. 


265 


Figs.    1989-1990.     Direct  Acting  Electro-Pneumatic   Switch   Movement   Layout  for  Single  Switch  Without 

Detector  Bar. 


Fig.  1991.     Diagram  of  Tracks  and  Signals,  South  Station,  Boston. 


Figs.    1992-1993.     Three-Way  Valve,   Used  for  Operat- 
ing  Electro-Pneumatic    Switches   by   Hand   During 
Installation    of    Plants    Under    Traffic. 


Fig.    1994.     Diagram    Show- 
ing   Operation   of    Valve 
Shown      in      Figs. 
1992-1993. 


266 


INTERLOCKING. 


Figs.  1995-1997 


and  lock  movement  is  shown  in  Figs.  2006-2008.  It  was  found 
that  in  many  cases  there  -was  not  sufficient  space  to  install  the 
electro-pneumatic  interlocking  machine  with  horizontal  rollers 
as  usually  made.  A  machine  was  therefore  designed  with 
vertical  rollers.  Figs.  2023-2024,  which  is  very  compact.  The 
interlocking  signals  used  in  the  subway  are  of  the  same  de- 
sign as  those  used  for  block  signaling  shown  in  Figs.  689-692. 
The  dwarf  signal  is  shown  in  Fig.  2025. 
Figs.  2026-2028  show  what  is  known  as  the  push  button 


of  another  button  will  put  it  normal  again.  Figs.  1989-1990 
show  a  switch  arranged  to  be  used  with  this  type  of  machine, 
and  the  circuits  for  operating  it  are  shown  in  Fig.  2003,  which 
also  shows  a  track  circuit  and  electric  lock  used  in  place  of 
a  detector  bar.*  The  switchbox  is  a  pole  changer  and  the 
electric  lock  is  polarized. 

Fig.  1991  is  a  diagram  of  the  tracks  and  signals  at  the 
South  Terminal  Station.  Boston,  which  are  operated  by  the 
machine  shown  in  Fig.  1955. 


r 


|br^° 

Tl 


y 


5 
6 


10 


One-Arm   Electro-Pneumatic    Suspended    Route    Signal. 


Names     of     Parts     of     Suspended 
Electro-Pneumatic    Signal; 

Figsf.   1995-1996. 

1  Cover 

2  Cylinder  Bracket 

3  Lever 

4  Shaft  -with  Cotters 

5  Up  and  Dozvn  Rod 

6  Post 

7  Semaphore  Shaft 
10  Lamp   Bracket 


Fig.  1997.     Electro-Pneumatic  Rotary  Pot  Signal. 


electro-pneumatic    interlocking   machine.      This   is   employed   liko  Fig.    2014    shows   the  arrangement   of  circuits   and   apparatus 

the    dwarf    interlocking   machine    where    a    number    of    switches       for  controlling  the  drawbridge  over  the  Charles  Hiver,   wiiere  it 


are  concentrated  in  a  yard  where  all  the  movements  are  low 
speed  and  no  interlocking  is  required  between  levers,  the 
machine  being  employed  merely  to  reduce  the  number  of  men 
necessary  to  operate  the  switch.  This  machine  is  so  arranged 
that  pressing  of  one  button  will  reverse  the  switch,  and  pressing 


is   crossed   by   the   Boston   Elevated   Railroad.      Attached   to   the 
structure    is    a    circuit    controller    F,    which    closes    the    circuit 


*NOTE. — For  electric  detection  applied  to  electro-pneumatic  in- 
terlocking see  Figs.  2001-2002,   2009-2013. 


Figs.  1998-2002 


INTERLOCKING. 


267 


energizing  the  draw  indicator  only  when  the  draw  is  in  proper 
position,  both  with  respect  to  its  vertical  and  horizontal  aline- 
ment.  In  series  with  this  is  another  contact  G,  which  insures 
the  proper  position  of  the  wedges  supporting  the  draw  ends 
before  the  circuit  is  closed.  When  this  circuit  is  complete  the 
draw  indicator  clears,  permitting  the  operation  of  the  draw 
lock  by  reversing  lever  21,  and  also  permitting  signals  18-L 


Fig.  2000  shows  the  circuits  for  the  control  of  the  electro- 
pneumatic  switch  valves  from  their  levers,  and  the  control  of 
the  levers  by  the  indicating  contacts  of  the  switch  movements, 
as  originally  used.  This  arrangement  of  control  circuits  has 
been  quite  extensively  used  for  electro-pneumatic  installations 
during  the  past  20  years  and  until  quite  recently. 

The  advent  of  electric  track  circuit  locking  of  switch  levers 
as  a  substitute  for  detector  bars  Is  a  feature  in  the  circuits 
shown  in  Fig.  2001.  These  retain  the  original  control  of  the 
switch  valve  by  the  lever,  but  draw  the  energy  for  indicating 


INDICATION  BOX 
R  ON 

SWITCH  MOVEMENT 


Fig.  2000.     Single  Switch  Control  and  Indication  Cir- 
cuits  as   Used   Without   Automatic   Locking. 

purposes  from  a  battery  feed  wire  running  throughout  the  plant 
for  general  purposes  that  call  for  energy  taken  from  points 
distant  to  the  tower.  The  current  supplied  to  the  Indication 
locks  of  the  switch  movement  is  thus  of  a  continuous  nature, 
and  not  present  simply  during  the  operation  of  the  switch,  as 
heretofore  when  this  current  supply  was  drawn  from  the  wiring 
energizing  the  lock  magnet  of  the  switch  valve.  The  same 
battery  wire  supplies  current  through  the  track  relay  for  the 
direct  operation  of  an  electric  lock  engaging  the  switch  lever, 
in  the  manner  which  is  customary  in  general  practice  on  other 
machines. 

Fig.  2002  shows  the  modifications  of  Fig.  2001,  in  which  the 
separate  electric  lock  is  dispensed  with  and  the  two  indication 


Fig.  2001.     Single   Switch   Control   and  Indicating  Cir- 
cuits with  Special  Circuit  and  Magnet  for  Automatic 
Switch  Locking. 

magnets  are  employed  to  perform  alternately  the  function  of 
automatically  locking  the  switch  by  a  train  on  the  track  cir- 
cuit. To  accomplish  this,  certain  additional  springs  were  applied 
to  the  switch  lever  for  transposing  the  indication  magnets  from 
the  duty  of  indicating  the  switch's  position,  to  the  duty  of 
locking  the  lever  automatically,  as  Is  apparent  from  the  dia- 
gram. This  is  the  method  that  has  been  generally  followed 
during  the  past  -five  years  in  electro-pneumatic  plants  having 
electric  track  circuit  switch  locking. 


Fig.         1998.         Electro- 
Pneumatic    Tandem 
Switch    and    Lock 
Movement       for 
Use  with  Mov- 
able Frogs. 


Fig.       1999.        Electro-Pneu- 
matic   Switch    and    Lock 
Movement    Attached 
to  Bed-Plate.  For 
Use  with  Sin- 
gle Switch. 


and  20-R  to  be  chared  for  traffic.  These  signals  are  also 
Interlocked  with  lever  21.  When  it  is  desired  to  open  the 
draw  (signals  18-L  and  20-R  being  set  in  the  stop  position), 
lever  21  is  moved  to  normal,  withdrawing  the  draw  lock,  which 
is  operated  by  the  plunger  cylinder  C.  When  this  lock  Is 
withdrawn  circuit  controller  B  closes  a  local  circuit  which 
energizes  lock  L  on  the  draw  tender's  gearing,  releasing  same 
and  permitting  him  to  open  the  draw. 


Fig.  2002.     Single   Switch   Control   and  Indicating  Cir- 
cuits   Adapted    to    Automatic    Switch    Lever    Lock- 
ing by  Indication   Magnets. 

Fig.  2003  shows  a  still  further  modification  <if  Figs.  2000  and 
2001  to  embrace  the  feature  first  referred  to  as  avoiding  the 
introduction  of  special  contacts  and  the  running  of  an  excessive 
number  of  wires  into  switch  movements  for  the  control  of  sig- 
nals by  the  position  of  switch  points.  This  diagram  embraces 
a  closed  circuit  indication  wire  in  one  position  of  the  lever  or 
the  other,  which,  acting  on  a  single  relay  or  indicator,  main- 
tains that  instrument  in  an  energized  state  only  as  long  as 
the  switch  lever  and  the  switch  coincide  in  position.  In  the 
event  of  either  one  moving  out  of  coincidence,  the  indicator  Is 


268 


INTERLOCKING. 


Figs. 2003-2008 


de-energized.  Through  suitably  arranged  contact  springs  on 
the  machine  levers,  these  indicators  are  made  to  control  the 
current  supplied  to  each  and  every  signal  leading  over  the  par- 
ticular switch  to  which  the  indicator  refers,  so  that  irrespective 
of  the  complication  and  size  of  an  interlocking  plant,  the  con- 


Fig.  2010  shows  the  arrangement  adapted  to  crossover  opera- 
tion. Fig.  2011,  likewise,  represents  the  adaptation  to  a  cross- 
over, while  Figs.  2012  and  2013  represent  the  operation  of  a 
crossover  by  the  methods  of  Figs.  2001  and  2002. 

It  will  be  noted  that  the  shifting  magnets  of  crossovers  are 


Locked. 


Reversed. 


ftes/'-sfcrnce 


Fig.  2003-2005.     Diagram  of  Typical  Circuits  for  Operating  Switches  from 
Electro-Pneumatic  Push-Button  Machine. 


Fig.  2006.     Electro-Pneumatic   Motion  Plate  Switch  and   Lock  Movement. 


Fig.  2007-2008.     Electro-Pneumatic  Motion  Plate  Switch  and  Lock  Movement  and  Detector*  Bar  Movement,  Ap- 
plied to  a  Single  Switch,  With  One  Detector  Bar  Ahead  of  Points;  Adjustable  Lock  Rod. 


trol  of  signals  of  secondary  importance  by  position  of  the 
switches  is  as  effectually  obtained  as  in  the  control  of  the 
signals  of  prime  importance  and  with  almost  no  additional  cost 
or  complications  in  the  equipment,  such  costs  and  complications 
as  are  embraced  being  confined  exclusively  to  the  equipment 
of  the  tower  itself. 


arranged  in  series,  whereas  the  lock  magnets  are  arranged 
in  parallel.  The  reason  for  this  is  that  the  duty  to  be  per- 
formed by  the  locking  magnets  is  considerably  In  excess  of  that 
to  be  performed  by  the  shifting  magnets  in  switch  valves  of 
modern  construction. 
To  obtain  a  more  nearly  instantaneous  withdrawal  and  appli- 


Figs.  2009-2016 


INTERLOCKING. 


269 


cation  of  the  D  valve  lock,  pin  valves  of  larger  area  have  re- 
cently been  Introduced,  which  somewhat  Increased  the  work  to 
be  performed  by  the  lock  magnet.  Hence,  a  greater  electrical 
energy  is  entailed  in  this  magnet  than  formerly,  and  the 
arrangement  in  parallel,  as  shown  on  the  diagrams,  permits  of 
operation  from  the  same  battery  or  generator  that  supplies  the 


Fig.  2009.     Single  Switch  Control  and  Indicating  Cir- 
cuits   Using    Indication    Magnets    for    Automatic 
Switch    Locking    and    Indication    Circuits    for 
Control  of  Signal  by  Position  of  Switch. 


INDICATION  BOX 

n    ON 

SWITCH  MOVEMENT 


ig.  2010.     Crossover   Control  and   Indicating  Circuits 
as   Used   Without   Automatic   Locking. 


\  teVER  LATCH  CIRCUIT  CONTROLLER 


Fig.  2011.     Crossover  Control  and   Indicating  Circuits 
With    Special    Circuit   and    Magnet   for   Auto- 
matic  Switch    Locking. 


Fig.    2012.      Crossover    Control    and    Indicating    Circuits 
Adapted  to   Automatic  Switch   Lever  Locking 
by   Indication  Magnets. 


^QUICKSWITCH  N  ^p    T^,^ 

!.  I        INITIATION   WIHES 

— '  ' '        H-jf^  x"  i^J  EVE^  CON'TACTS" "  """  " 


BOX 
MOVEMEXT 


Fig.    2013.     Crossover    Control    and    Indicating    Circuits 

Using   Indication    Magnets   for   Automatic   Switch 

Locking    and    Indication    Circuits   for    Control 

of  Signal  by  Position  of  Switch. 

shifting  magnets  of  switch  valves,  without  resorting  to  a  dif- 
ference in  the  resistances  of  switch  valve  magnets  In  general. 

The  extra  consumption  of  energy  thus  caused  by  the  lock 
magnets  is  insignificant,  fqr  the  reason  that  these  magnets  are 
never  upon  closed  circuit  excepting  during  the  operation  of 
the  switch. 


A  B 
C 


Names   of   Parts   of   Fig.   2014. 

Circuit  Closer  and  Bridge  Bolt  Keeper 
Electro-Pneumatic  Bridge  Lock  Plunger 
D  E    Brackets,  Operating  F 

F    Bridge  Alinement  Circuit  Closer 
G    Circuit  Closer  on  Wedges  of  Bridge 
L    Electric  Lock  on  Valve  of  Draw  Mechanism 
i8-L,  2O-R    Bridge  Signals 


-r-\   -e 

E         '-F 


Circuits    Controlling   Gate 
Indicators. 

Gate   Indicators. 


Circuits  Controlling  Draw  Lock  and  Signals. 


234-     Drt»  Gates 


Figs.  2014-2016.     Circuits  for  Drawbridge  Protection.     Boston   Elevated    Railroad. 


270 


INTERLOCKING. 


Figs.  2017-2022 


Figs.    2017-2019.     Electro-Pneumatic    Switch    and    Lock  Movement    Applied    to    Single    Switch    With    One    De- 
tector Bar  Ahead  of  Points;  Cylinder  and  Movenent  Set  on  Plank.   (Later  Construction  Provides 
for  an  Iron  Bed  Plate,  as  in  Figs.  1999  and  2006.) 

D-Valve 

Valve  Seat 

Spring  for  Stuffing  Box 

Gland  for  Stuffing  Box 

Packing  for  Stuffing  Box 

Nut  for  Stuffing  Box 

Gasket  for  Piston  Seat  in  Valve 

Chamber 

Gasket  for  Head  of  Valve  Cham- 
ber 

Gasket  for  Valve  Seat 
Union  for  Valve  Chamber 
Washer  for  28 
Strainer  for  28 
Oil  Plug 

Tap  Bolt  for  Yoke 
Tap    Soft   for    Fastening    Valve 

Chamber  and  Seat  to  Cylinder 


Fig.  2020.     Lock  Rod,  for  Figs.  2017-2019. 
Names  of  Parts  of  Electro-Pneumatic  Switch  Valve;  Figs.  2021-2022. 


i 

2 

4 
5 
6 

7 
8 

9 
ii 


Valve  Chamber 

Guide  for  Pin  Valve 

Pin  Valve  Plug 

Pin  Valve 

Pin  Valve  Spring 

Head  for  Valve  Chamber 

Yoke 

Lock  Cylinder 

Head  for  Lock  Cylinder 


13 


15 
16 

17 
18 


Pin  Valve  Guide  for  Lock  Cylin- 
der 

Pin  Valve  for  Lock  Cylinder 

Pin  Valve  Spring  for  Lock  Cylin- 
der 

Piston  for  Lock   Cylinder 

Spring  for  Lock  Cylinder 

Piston  for  Switch  Valve 

Piston  Rings  for  17 


19 
20 

21 

22 
23 
24 
25 

26 

27 
28 
2Q 
30 
31 
32 

33 


32      8 


4    27    20     19     21     22    23     24 


Figs.    2021-2022.     Electro-Pneumatic    Switch    Valve. 


Figs.  2023-2028 


INTERLOCKING. 


271 


Figs.      2023-2024.     Electro-Pneumatic      Interlocking 
Vertical  Roller   Type. 


Machine; 


Fig.  2025.   Electro-Pneumatic 
Dwarf  Slide  Signal.    Inter- 
borough    Rapid    Transit 
Company. 


Fig.  2026.     One  Section  of  Mech- 
anism,    Fig.     2028,     Electro- 
Pneumatic     Push-Button 
Machine. 


Fig.  2027.     Arrangement  of  Insulated  Joints  at  Switches 
Controlled  by  Push-Button  Machine. 


Fig.    2028.     Electro-Pneumatic    Push    Button    Machine. 
Union  Switch  &  Signal  Company. 


272 


INTERLOCKING. 


Fig.  2029 


LOW-PRESSURE  PNEUMATIC  INTERLOCKING 


Interlocking  apparatus  worked  by  compressed  air  at  low 
pressure  (15  Ibs.  per  sq.  in.)  and  with  no  electrical  features 
is  made  by  the  General  Railway  Signal  Co.,  and  is  in  use 
on  a  number  of  railways.  Compressed  air  in  separate  pipes 
is  employed  to  control  the  admission  of  pressure  to  the  switch 
and  signal  cylinders.  Pressure  is  admitted  to  working  cyl- 
inders by  valves  actuated  by  large  rubber  diaphragms,  which 
are  worked  by  air  at  seven  Ibs.  pressure.  The  lever  of  a  switch 
cannot  complete  its  stroke  until  the  switch  has  actually  moved 
home  and  conveyed  an  indication  of  the  fact  to  the  cabin.  The 
interlocking  is  mechanical,  the  parts  being  made  small.  They 
are  of  the  "Standard"  type  (Figs.  855-901).  While  the  action 


versed.      Thus    absence   or   failure  of  power   will    always    leave 
the  signal   in  the  stop  position. 

The  appearance  of  the  machine  is  shown  in  Fig.  2040,  and 
the  way  in  which  the  pressure  is  conveyed  and  controlled  la 
shown  in  Figs.  2029  and  2031.  Fig.  2029  represents  the 
arrangement  of  valves  and  pipes  forming  the  connection  be- 
tween the  interlocking  machine  and  a  switch  cylinder.  The 
principal  parts  are :  S,  switch  rails  ;  s,  lock-rod ;  s\  throw  rod ; 
M,  motion  plate ;  C,  switch  cylinder ;  D,  indicating  valve ; 
R2,  R3,  RS  R5,  controlling  valves  or  relays ;  L,  L2,  operating 
bar  and  slide  valve  on  lever ;  I,  I2,  indication  cylinders ;  H, 
interlocking  tappet ;  X,  air  reservoir. 


Names  of  Parts  of  Low 
Pressure  Pneumatic 
Control  Mechanism; 
Fig.  2029. 

C    Switch   Cylinder 
D    Indicating  Valve 
H     Tappet 
I     Normal   Indication 

Cylinder 
I2    Reverse   Indication 

Cylinder 
L    Lever 
L2  Slide  Valve 
M  Motion   Plane 
R2  Normal       Indication 

Diaphragm     Valve 

or  "Relay." 
Rs  Reverse        Indication 

Diaphragm     Valve 

or  "Relay." 


Normal  Operating 
Diaphragm  Valve 
or  "Relay." 

Reverse  Operating 
Diaphragm  Valve 
or  "Relay." 

S^uitch  Rails. 

Air  Reservoir 

Reverse  Control  Pipe 

Normal  Control  Pipe 

Long  Tie  Support- 
ing C 

Lock   Rod 

Tliroiu  Rod 

Normal  Indication 
Pipe 

Reve  rse  Indica  tio  n 
Pipe 

Normal  Indication 
Pipe  Between  Cylin- 
der and  Indicating 
Valve 

Reverse      Indication 


Fig.  2029.     Low-Pressure   Pneumatic   Switch   Movement  and   Lever  Connections. 


of  compressed  air  in  pipes  is  not  instantaneous,  like  an  electric 
impulse,  the  movement  of  switches  is  effected  quickly  enough 
for  all  practical  purposes  ;  and  at  ordinary  distances  the  move- 
ment of  a  signal  is  practically  simultaneous  with  its  lever. 

The  distinctive  features  of  the  low-pressure  pneumatic  inter- 
locking machine  are:  (1)  A  row  of  slide  valves  (called  levers) 
like  that  shown  in  outline  at  L  and  L2,  Figs.  2029  and  2031. 
(2)  The  mechanical  interlocking  frame,  placed  vertically  on 
the  front  of  the  machine.  The  manner  of  connecting  the  lever 
with  the  interlocking  is  indicated  by  the  position  and  arrange- 
ment of  the  tappet  H  in  Fig.  2029.  (3)  The  indicating  cylinders 
and  their  relays  on  each  lever,  as  shown  in  Figs.  2029  and 
2031. 

Application  of  air  pressure  is  required  in  every  case  to 
accomplish  any  movement.  To  move  a  switch  or  signal  from 
normal  to  reverse  position  and  to  receive  a  return  indication 
at  the  machine,  an  air  pressure  must  be  applied  at  the  lever. 
All  signals  are  held  In  the  proceed  position  by  air  pressure 
under  the  piston,  the  entire  reverse  operating  line  being  charged 
from  the  tower  to  the  signal  when  the  signal  lever  Is  re- 


To  reverse  the  position  of  the  switch  the  signalman  pulls  the 
lever  L  to  the  left.  In  doing  this  he  admits  air  (from  the 
main  supply  X  through  the  valve  L2)  through  pipe  a  to  valve 
R',  which  opens  communication  from  the  supply  pipe  X  to 
the  right-hand  end  of  the  cylinder  C,  pushing  the  piston  to 
the  left.  Observing  now  the  slots  in  Lr  and  M,  It  will  be  noted 
that  after  about  one-half  of  the  stroke  L  has  been  completed 
it  is  stopped  by  the  piston  rod  of  I2 ;  but  the  operation  of 
valve  R5,  already  accomplished,  causes  M  to  move  through  the 
whole  of  its  stroke.  This  stroke  of  M  is  uninterrupted,  but  It 
performs  in  succession  three  functions.  The  first  part  of  the 
stroke,  say  one-third,  does  not  move  the  switch,  but  valve 
D  is  moved  far  enough  to  close  the  two  pipes  on  its  right, 
while  those  on  its  left  are  open  to  the  atmosphere.  At  the 
same  time  lock  bar  s  has  been  liberated  by  withdrawal  of  a 
dog  attached  to  M  from  notch  in  s.  As  M  moves  through  the 
next  or  middle  portion  of  its  stroke,  it  moves  the  switch ;  but 
it  now  produces  no  effect  on  valve  D,  because  the  rod  of  D 
is  now  engaged  by  they  straight  portion  of  its  slot  in  plate  M. 
The  switch  being  set,  the  third  and  final  part  of  the  stroke 


Figs.  2030-2032 


INTERLOCKING. 


273 


Fig.  2030.     Low-Pressure   Pneumatic  Switch  and  Lock  Movement  With  Gain-Stroke  Lever.     New  York  Central 

&  Hudson  River. 

Names  of  Parts  of  Low  Pressure  Pneumatic  High  Signal  and  Control 
Mechanism;  Fig.  2031. 


Signal  Arm  R1 

Signal  Cylinder  R2 
Indicating  Valve  Lever~R3 

Indicating  Valve  X 

Tappet  a 

Indication  Cylinder  b 

Lever  e 

Slide  Valve  n 


Reverse  Indication  Diaphragm  Valve  or  "Relay" 
Normal  Operating  Diaphragm  Valve  or  "Relay" 
Reverse  Operating  Diaphragm  Valve  or  "Relay" 

Air  Reservoir 

Reverse  Control  Pipe 

Normal  Control  Pipe 

Normal  Control  Pipe  on  Signal 

Indication  Pipe 


Fig.  2031.     Low-Pressure  Signal   Movement 


Fig.    2032.      Low-Pres- 
sure   Pneumatic 
Dwarf    Signal. 


of  M  locks  the  switch  by  pushing  a  second  dog  attached  to 
M  through  a  second  notch  in  s  ;  and  also  (but  not  until  after 
the  dog  has  entered  its  notch)  the  plate  changes  valve  D  so 
as  to  connect  together  the  two  pipes  y  and  v.  This  con- 
veys pressure  from  the  supply  through  R5  and  D  to  valve  Rs, 


which  valve  then  admits  air  from  the  supply  to  I2,  forcing 
the  piston  rod  upward,  and,  by  means  of  the  diagonal  portion 
of  the  slot  in  lever  L,  forcing  It  to  complete  its  stroke.  This 
return  action  takes  place  at  ordinary  distances  in  from  one 
to  three  seconds.  In  rapid  work,  this  automatic  completion 


274 


INTERLOCKING. 


Figs.  2033-2037 


of  the  stroke  of  the  lever  saves  an  appreciable  portion  of  the 
signalman's  time.  By  the  action  of  L2  pipe  a  is  now  opened 
to  the  atmosphere,  valve  R5  is  released  from  pressure,  and  R4 
is  closed ;  so  that  the  right-hand  pipe  to  cylinder  C  and  Its 
connection  to  and  through  D  are  open  to  the  atmosphere.  All 
four  operating  pipes  are  now  at  atmospheric  pressure. 

By  the  movement  of  L,  tappet  H  has  been  moved  so  as  to 
produce,  in  the  first  part  of  the  stroke  of  L,  the  proper  me- 
chanical locking  of  conflicting  levers,  and  in  the  last  part  of 
this  stroke,  the  proper  unlocking  in  the  same  manner  and 


diaphragm  operating  the  second  function  in  the  same  manner 
as  described  for  the  operation  of  the  first  function.  Pipes  to 
any  number  of  movements  may  be  connected  in  series  and 
operated  from  one  lever  in  this  manner,  the  indication  from 
a  preceding  movement  operating  a  following  one,  the  last 
movement  to  operate  giving  the  indication  at  the  machine  and 
automatically  completing  the  stroke  of  the  lever. 


Ml! 


Fig.  2033.     Pneumatic  Diaphragm  Valve  or  "Relay. 


Fig.    2034.      Indicating    Valve    for 
High   Signal    (B,    Fig.   2031). 


0/recf  connection  So 

"Up  and  Dow  "met  ~*  ^ 


z  Pipe  Tap 
Normal  Intet 


T 


/nd/caf/on 


Figs.  2035-2036.     Pneumatic  High  Signal. 


ffererse  /n/ef 
U 81 .d 

Fig.  2037.     Improved  Type  of  Cylinder  for 
Pneumatic    High    Signal. 


sequence  that  the  same  interlocking  would  have  effected  in  a 
mechanical  interlocking  machine. 

To  move  the  switch  back  to  its  original  position,  the  opposite 
set  of  pipes  is  used.  The  lever  L  is  pushed  to  the  right ;  air 
through  b  actuates  R4,  and  the  return  indication  to  the  cabin 
actuates  R2  and  lifts  the  piston  in  I. 

A  crossover  switch  or  slip  with  movable  point  frogs  is  op- 
erated in  the  same  manner  excepting  that  the  functions  are 
connected  in  series,  the  air  leaving  valve  D,  going  to  the 


To  work  a  signal,  valves  and  operating  pipes  are  used  of  the 
same  general  style  as  those  for  a  switch,  but  there  is  only  one 
indicating  valve  and  one  indicating  cylinder,  as  it  is  considered; 
unnecessary  to  assure  the  attendant  that  a  signal  is  in  t 
proceed  position.  The  signal  connections  are  shown  in  Fig.; 
2031.  The  principal  parts  are:  A,  signal  arm;  A2,  signal  cyl-: 
inder ;  As,  lever  to  work  indicating  valve;  B,  indicating  valve; 
II3  and  R3,  diaphragm  valves  or  relays,  controlling  the  admis- 
sion of  air  to  the  top  and  bottom,  respectively,  of  the  signal 


Figs.  2038-2040 


INTERLOCKING. 


275 


cylinder  ;  R1,  diaphragm  valve  controlling  admission  of  air 
to  cylinder  I.  The  signal  being  in  the  normal  or  stop  position, 
the  indicating  valve  B  is  in  a  position  to  maintain  a  con- 
nection between  the  two  pipes  attached  to  it ;  but  as  soon  as 
the  signal  arm  leaves  the  horizontal  position  the  valve  shuts 
off  this  connection. 

To  clear  the  signal  the  signalman  pulls  L  to  the  left  the 
whole  length  of  its  stroke.  By  this  movement  L2,  admitting 
air  to  pipe  a,  actuates  valve  R3,  which  supplies  air  to  the 
lower  end  of  cylinder  A2  and  pushes  up  the  piston,  putting 
the  signal  in  the  proceed  position.  The  air  impulse  is  trans- 
mitted so  quickly  that  at  the  average  distance  (say  500  ft.  or 
less)  the  movement  of  the  signal  Is  practically  simultaneous 
with  the  movement  of  the  lever.  The  signal  remains  in  the 
proceed  position  as  long  as  L  is  pulled  to  the  left.  To  restore 


part  of  the  case,  and  thereby  admits  air  at  15  Ibs.  per-sq.  in.  to 
move  the  piston  in  the  switch  or  signal  cylinder.  The  movement 
of  the  diaphragm  is  only  one-fourth  in. 

The  operating  and  indicating  pipes  extending  to  switches  and 
signals  are  one-half  in.  in  diameter.  The  supply  pipes  from  the 
air  reservoirs  are  larger,  the  size  being  varied  according  to 
the  number  of  switches  and  signals  to  be  operated.  The  air 
as  it  comes  from  the  compressor  is  run  through  cooling  pipes 
for  the  purpose  of  precipitating  moisture. 

Any  number  of  signals  controlling  relative  movements  over 
the  same  switches  may  be  connected  up  to  one  signal  lever  by 
placing  selector  valves  at  switch  points  to  control  the  admis- 
sion of  air  to  the  proper  signal  line.  This  method  provides 
practically  the  same  protection  as  bolt  locking  the  switch 
points  with  signal  lines  at  mechanical  plants. 


Figs.  2038-2039.     Low  Pres- 
sure Pneumatic  Dwarf  if 
Signal. 


O 


Fig.    2040.     Low-Pressure    Pneumatic    Interlocking    Machine. 


it  to  the  normal  or  stop  position,  L  is  pushed  to  the  right  until 
it  is  stopped  by  the  piston  rod  of  I  (at  the  end  of  the  hori- 
zontal part  of  the  slot  in  L).  With  L  in  this  position,  pipe  I 
is  charged  and  valve  R2  is  opened.  The  passage  between  pipes 
c  and  n  (through  B)  is  now  closed,  so  that  the  opening  of 
R:  admits  air  from  the  supply  to  the  upper  end  of  A2.  This 
restores  the  signal  to  the  horizontal  position,  and  by  means 
of  A8  opens  valve  B.  Air  now  passes  from  e  through  B  and  ft 
to  R1,  and  the  latter  causes  air  to  enter  I  and  complete  the 
re-turn  stroke  of  L  by  the  action  of  the  piston  rod  on  the 
diagonal  part  of  the  slot.  Pipes  b,  e  and  n  are  now  at  at- 
mospheric pressure ;  and  the  parts  are  in  tine  same  position  as 
at  the  beginning. 

In  Fig.  2033  is  shown  the  diaphragm  valve,  which  is  called 
the  "relay,"  its  function  being  similar  to  that  of  an  electro- 
magnetic relay  in  electrical  apparatus.  This  valve  is  actuated 
by  air  at  seven  Ibs.  pressure.  This  pressure,  admitted  beneath 
the  circular  rubber  diaphragm  eight  in.  in  diameter,  pushes 
up  the  cylindrical  valve,  placed  vertically  in  the  upper 


Fig.  2030  shows  the  method  of  providing  a  gain  stroke  lever 
from  switch  and  lock  movement  to  switch  point,  and  also 
shows  the  general  appearance  of  a  switch  connected  up  to 
(he  low  pressure  system,  for  either  rear  or  advance  bar 
movements. 

The  common  type  of  semaphore  movement  used  with  the 
low  pressure  pneumatic  system  is  shown  in  Figs.  2035-2036  ;  the 
movement  is  effected  by  the  operation  of  the  relays,  controlled 
by  the  signal  lever  in  the  machine  as  explained  in  Fig.  2031. 
An  improved  semaphore  movement,  known  as  style  B,  is 
shown  in  Fig.  2037.  The  principles  of  operation  are  the  same 
as  described  in  connection  with  Fig.  2031,  excepting  that  the 
indication  is  controlled  by  a  piston  so  arranged  as  to  pass  the 
air  from  the  normal  side  of  the  piston  to  the  indication  line 
when  the  signal  arm  has  assumed  the  stop  position. 

Figs.  2038-2039  show  a  style  B  pneumatic  dwarf  signal.  The 
operation  is  effected  through  the  same  control  medium  as 
shown  in  Fig.  2031;  the  indication,  however,  is  controlled  by 
a  piston  valve  in  the  same  manner  as  shown  in  Fig.  2037. 


276 


INTERLOCKING. 


Figs.  2041-2044 


ELECTRO-MECHANICAL  INTERLOCKING 


The  electro-mechanical  machine  applies  many  of  the  advan- 
tages of  power  interlocking  to  a  mechanical  plant ;  requires 
less  energy  for  Its  operation ;  provides  a  reliable  means  for 
switch  and  signal  indications;  permits  the  use  of  electric  de- 
tector locking ;  eliminates  facing  point  locks,  bolt  locks  and 
detector  bars  and  in  addition  reduces  the  size  of  the  tower 
required. 


Fig.   2043.     Electro-Mechanical   Interlocking  Machine. 
General    Railway    Signal    Company. 


Fig.  2041.     Style  "P"   Electro-Mechanical   Interlocking 
Machine.     Union   Switch   &  Signal   Company. 


-    '          i 


Fig.    2042.      Style    "S"    Electro-Mechanical    Interlocking 
Machine.     Union   Switch    &   Signal    Company. 


Fig.    2044.     Electro-Mechanical    Interlocking    Machine. 
General    Railway    Signal    Company. 


UNION    STYLE   "P." 

The  large  machine  is  of  the  Saxby  &  Farmer  type  and  is  fur- 
nished in  standard  sections,  the  levers  being  spaced  five  in. 
center  to  center.  The  miniature  levers,  spaced  two  and  one- 
half  in.  centers,  are  mounted  above  the  large  levers  and  so 
arranged  that  the  small  controlling  switch  levers  are  directly 
over  the  large  levers  controlled  by  them.  The  miniature  signal 
control  levers  are  placed  between  the  switch  levers  and  are 
for  control  of  power  operated  signals. 

The  mechanical  locking  between  levers  is  actuated  entirely 
by  the  miniature  levers,  thus  reducing  to  a  minimum  the  Ha 
bility  of  forcing  or  straining  the  locking.  The  miniature  levers 


Figs.  2045-2046 


INTERLOCKING. 


277 


In  turn  lock  the  large  levers  through  vertical  rods  connected 
to  the  shaft  and  horizontal  rods  operated  by  the  rocker  on  the 
large  levers,  the  locking  being  accomplished  by  slots  in  the  rods 
smiliar  to  the  slots  in  mechanical  bolt  locks. 

The  actual  operation  of  a  switch  is  accomplished  by  the  large 
lever,  and  the  mechanical  locking  actuated  and  indication  taken 
from  the  miniature  one.  The  electric  levers  are  fitted  with  the 
electric  lock  and  spring  combination  features  identical  with 
those  used  on  the  electro-pneumatic  interlocking  machine  as  ex- 
plained in  the  description  of  that  machine. 

The  miniature  levers  are  made  in  multiples  of  two.  The 
operation  of  a  switch  lever  is  as  follows  : 

First:  Throw  the  miniature  lever  to  the  middle  position, 
actuating  the  locking  and  releasing  the  large  lever  for  the 
operation  of  the  switch. 

Second:    Operate  the  large  lever. 

Third:  Complete  the  stroke  of  the  miniature  lever  after  the 
indication  is  received,  which  locks  the  large  lever  and  also 
completes  the  stroke  of  the  mechanical  locking,  releasing  the 
signal  levers,  etc. 


UN'lOX    STYLE    "S." 

The  electric  levers  in  the  style  "S"  machine  are  made  up  in 
ultiples    of   four.      Any    number,    therefore,    not    exceeding    the 


capacity  of  a  given  mechanical  machine  frame  may  be  placed 
above  such  a  machine  as  desired. 

The  electric  levers,  while  principally  intended  for  the  control 
of  signals,  can  also  be  used  for  other  purposes,  such  as  electric 
locking  between  adjoining  towers,  between  towers  and  outlying 
switches,  direction  control  of  traffic,  etc. 

The  electric  levers  for  the  control  of  signals  are  placed  five 
in.  centers  to  correspond  with  the  spacing  of  shafts  in  the 
locking  bed  ;  levers  which  do  not  have  connection  with  the  me- 
chanical locking  may  be  placed  intermediate  of  these  levers 
without  increasing  the  length  of  the  frame. 

The  electric  levers  are  fitted  with  the  electric  lock  and  spring 
combination  features  identical  with  those  used  on  the  electro- 
pneumatic  interlocking  machine. 

From  cranks  on  the  shafts  of  the  electric  levers,  vertical  rods 
connect  to  rack  and  pinion  drivers  for  operating  the  locking 
bars  in  the  bed  of  the  mechanical  machine,  these  drivers  being 
free  to  turn  on  the  locking  shafts  of  mechanical  levers.  By 
this  means  any  desired  locking  can  be  secured  between  the 
mechanical  and  the  electric  levers. 

The  electric  levers  with  their  supports  and  connections  can 
be  applied  to  existing  mechanical  machines  by  revising  the 
locking  to  suit  conditions  and  inserting  the  required  number 
of  special  locking  drivers  in  the  locking  bed. 


POWER  OPERATED  SIGNALS  AT  MECHANICAL  PLANTS 


Where  power-operated  semi-automatic  signals  are  used  at 
mechanical  interlocking  plants,  provision  is  usually  made  to 
compel  the  signalman  to  put  his  signal  lever  normal  after  the 
passage  of  a  train.  Such  signals,  if  of  the  automatic  type, 
will  clear  as  soon  as  the  train  leaves  the  block  if  the  lever 
remains  reversed,  and  permit  another  train  to  follow,  which 
might  result  in  delays.  For  this  purpose,  some  form  of  "stick" 
relay  wiring  may  be  employed.  Fig.  2051  shows  circuits  for 
this  purpose.  The  circuit  controllers  shown  are  operated  by 
the  lever  latch.  The  500-ohm  stick  relay  is  kept  energized 
tinder  normal  conditions  by  a  circuit  as  follows :  From  the 
battery  D,  through  wires  4,  6,  circuit  controller  A,  wires 


Fig.    2045.     Diagram    of    Control    Circuits    for    Three- 
Arm    Style   "B"   Union    Semaphore   Distant   Signal 
at    Mechanical    Interlocking    Plant.    Penn- 
sylvania Railroad. 

9  and  12,  coils  of  relay,  wires  10  and  8,  circuit  controller  C 
und  wire  3  to  battery.  Current  can  also  flow  through  wire  5, 
relay  point,  wires  11  and  12  and  to  battery  through  coils. 
Raising  the  latch  opens  circuit  controller  A.  Lowering  latch 
with  lever  reversed  closes  circuit  controller  B  and  opens  C ; 
C  does  not  open,  however,  before  B  closes.  Current  now  flows 
from  battery  through  wires  4  and  5,  relay  point,  wires  11  and 
12,  coils  of  relay,  wires  10  and  7,  circuit  controller  B,  wire  2, 
track  relay  point,  wire  13,  signal  mechanism,  wire  1,  to  battery. 
This  clears  the  signal.  Passage  of  a  train  opens  the  track 
relay  points,  putting  the  signal  to  the  stop  position  and 
opening  the  circuit  of  the  500-ohm  stick  relay.  As  the  signal 
control  circuit  passes  through  the  point  of  this  relay,  the  signal 
cannot  again  clear,  because  this  relay  will  not  be  energized 
again  until  the  lever  is  latched  in  the  normal  position.  If  the 
resistance  of  the  coil  through  which  this  current  passes  at  the 
signal  is  less  than  500  ohms,  the  stick  relay  winding  should  be 
reduced  accordingly. 

Another  circuit  arrangement  for  accomplishing  the  same  re- 
sults is  shown  in  Fig.  2052.  The  stick  relay  has  two  windings, 
one  of  which,  D,  is  energized  by  the  battery  A  through  con- 
troller contacts  F  and  E  and  wires  1,  2,  3  and  0.  The  circuit 


controller  is  of  the  snap  type.  Contact  G  must  close  just 
before  the  other  two  open  when  the  lever  latch  is  lowered 
with  lever  reversed ;  and  E  and  F  must  close  only  when  latch 
is  lowered  with  lever  normal.  With  lever  reversed  and  latched, 
current  flows  from  battery  A,  through  wire  1,  controller  con- 
tact G,  wire  4,  coil  C  of  stick  relay,  wire  5,  contact  on  stick 
relay,  wire  6,  contact  on  track  relay,  wire  7,  signal  mechanism, 
and  wire  0  back  to  battery.  This  keeps  the  stick  relay  en- 
ergized and  clears  the  signal.  The  presence  of  a  train  in  the 
block  opens  the  track  relay  and  breaks  the  circuit  for  the 
signal  and  stick  relay.  This  puts  the  signal  to  stop  and  opens 
the  stick  relay,  which  cannot  again  pick  up  until  the  lever  is 
latched  normal. 

Fig.   2047   is  a  diagram  of  circuits  in  use  on  the  Erie  Rail- 
road   for    electrically    operated    distant    and    advance    signals, 


Fig.  2046.     Diagram  of  Control  Circuits  for  Two-Arm 
Semaphore  Distant  Signal  at  Mechanical  Inter- 
locking Plant.     Union  Switch  &  Signal 
Company's  Style  "B"   Signal. 

with  electric  switch  locks  for  outlying  switches  at  an  inter 
locking  plant.  Circuits  east  and  westbound  are  similar  and 
have  similar  numbers.  The  circuit  for  distant  signal  1  is  as 
follows :  From  the  battery  at  the  tower,  through  back  con- 
tact on  indicator  I,  circuit  controller  P  (on  lever  1),  wire  1, 
circuit  controller  V  (on  signal  3),  relay  D  at  signal  1,  to 
common  wire  6,  back  to  battery.  Indicator  I  is  operated  by 
circuit  from  battery  H  at  signal  2,  through  circuit  controller 
G',  wire  4'  and  hand  switch  L.  Therefore,  to  clear  signal  1, 
advance  signal  2  must  be  cleared  (closing  the  contact  on  I) 
and  also  the  home  signal  3. 

Advance  signal  2  is  controlled  by  a  circuit  from  the  main 
battery  through  circuit  controller  S  (on  lever  2),  wire  5',  re- 
lay D  (at  signal  2),  circuit  controller  B'  (on  electric  switch 
lock  A'),  to  common  wire  6'.  If  the  lock  A'  has  been  released 
to  open  the  switch.  B'  will  prevent  signal  2  from  clearing. 

The  switch  lock  A'  is  controlled  by  the  hand  switch  L,  using 
the  same  circuit  from  battery  H  at  signal  2  that  operates 
indicator  I.  When  L  is  reversed  this  current  passes  through 
wire  3',  switch  lock  A',  wire  5'  back  to  battery.  W'hen  L  is 
reversed  indicator  I  is  energized  by  the  tower  battery,  thereby 
keeping  the  circuit  for  distant  signal  1  open.  Locks  N  and 


278 


INTERLOCKING. 


Figs.  2047-2050 


Figs.  2051-2054 


INTERLOCKING. 


279 


O  act  on  the  home  signal  levers  to  lock  the  latches  while  the 
distant  signal  is  clear,  so  that  the  lever  may  be  put  normal, 
but  not  latched  in  that  position.  The  telephones  U  are  in- 
stalled in  the  tower  and  at  the  outlying  switches.  Trainmen 
use  these  to  request  an  unlock  from  the  signalman.  The  tele- 
phone circuit  is  carried  on  the  main  common  on  one  side,  and 
the  ground,  through  condensers,  C,  on  the  other. 


G.    R.    S.    MODEL    2.V    SIGNAL    USING   DYNAMIC    INDICATION. 

Figs.  2053-2054  show  typical  circuits  for  power  operated  sig- 
nals when  controlled  by  the  levers  of  a  mechanical  interlocking 
machine.  These  circuits  make  use,  on  low  voltage  signals,  of 
the  dynamic  indicariou  which  is  used  in  connection  with  the 


the  indicating  current  effectually  checks  the  speed  of  the 
mechanism,  thereby  eliminating  the  necessity  of  having  a  dash- 
pot  to  prevent  shock  to  the  parts  on  the  arrival  of  the  blade 
at  the  normal  position. 

It  will  be  seen  that  neither  false  operation  nor  indication 
can  result  from  a  cross  between  the  operating  and  common 
wires,  evidence  of  existing  trouble  being  given  by  the  blowing 
of  the  fuse  in  the  operating  circuit.  Provisions  are  made  to 
properly  safeguard  the  circuits  when  two  or  more  signals  are 
controlled  by  wires  located  on  the  same  pole  line,  this  pro- 
tection being  maintained  in  every  case  through  contacts  whose 
integrity  is  checked  at  each  operation. 

The  use  of  this  type  of  control  for  power  operated  signals 
eliminates  the  necessity  of  having  isolated  batteries  with 


Fig.  2051.     Circuit  for   Power-Operated   Signal  at  Mechanical  Interlocking  Plant. 


Fig.  2052.     Circuit  for  Power-Operated  Signal  at  a  Mechanical  Interlocking  Plant. 


G.  R.  S.  110-volt  all-electric  interlocking  system.  The  signals 
are  capable  of  being  controlled  semi-automatically  by  track  cir- 
cuits or  non-automatically,  and  are  designed  to  operate  through 
two  or  three  positions,  upper  or  lower  quadrant,  right  or  left 
hand.  The  apparatus  required  has  been  reduced  to  a  minimum 
through  the  use  of  a  central  source  of  energy. 

The   low   voltage   Model   2A   signals  are  operated  from   a  bat- 
tery in  the   tower,   which   delivers   either   10  or  20  volts  at  the 


Fig.    2053.     Model    "2A"   Non-Automatic   Signal    Oper- 
ated from  Mechanical   Interlocking  Plant.  General 
Railway  Signal  Company. 

signal  location.  The  signal  mechanisms  used  with  circuits 
shown  in  Figs.  2053  and  2054,  with  the  exception  of  the  motors, 
are  shown  in  Figs.  .1814-1815  and  1818-1819  respective- 
ly. The  release  effected  by  the  dynamic  indication  is 
received  and  stored  by  a  suitably  arranged  style  B  lock,  with 
which  the  controlling  lever  is  equipped.  The  generation  of 


their  expensive  housing  at  each  signal  location ;  it  also 
eliminates  control  relays  and  relay  boxes,  cuts  out  the  Indi- 
cation wire  necessary  to  battery  indication,  and  in  plants 
where  more  than  two  such  signals  are  installed  effects  a  con- 
siderable saving  in  the  number  of  cells  required  to  operate 
the  functions  in  question. 

When    distant   signals   are   controlled    by    this    circuit,    special 
locking    is    employed    which    permits    the    home    signal    to    be 


'::>  '  ^     A3     REQUlRtO 


Fig.   2054.     Model   "2A"   Semi-Automatic  Signal   Oper- 
ated   from    Mechanical    Interlocking    Plant.      Gen- 
eral Railway  Signal  Company. 

placed  at  stop,  if  for  any  reason  the  lock  on  the  distant 
lever  should  not  be  released  thereby  preventing  the  distant 
lever  from  being  latched  in  the  full  normal  position ;  the 
home  lever,  however,  may  not  be  placed  full  normal  and  the 
route  consequently  may  not  be  released  until  the  proper  indi- 
cation has  been  received. 


280 


INTERLOCKING. 


Figs.2055-2056 


ELECTRIC  LOCKING. 


In  a  mechanical  interlocking  plant  there  are  detector  bars 
to  prevent  switches  being  thrown  while  a  train  is  upon  them, 
and  they  have  been  a  safety  device  of  great  value.  But  the 
only  check  on  the  manner  in  which  the  signalman  handles 
his  levers  at  such  a  plant  is  the  dog  locking  and  the  detector 
bars,  and  with  moderate  speed  of  trains  and  a  high  intelli- 
gence in  signalmen  nothing  more  could  be  desired.  But  speeds 
have  been  increased  to  such  an  extent  that  distant  signal 
indications  must  be  given  farther  away,  and  power  has  been 
Introduced  to  work  switches  and  signals. 

Increased  speed  means  more  space  to  stop  in,  and  with  the 
simple  mechanical  plant  there  is  nothing  to  prevent  a  signal- 
man from  changing  the  route  after  a  train  has  passed  tbo 
distant  signal  at  clear ;  this  might  lead  to  running  a  train  off 


the  high-speed  routes.  For  example,  suppose  that  the  switches 
are  set  up  for  the  route  from  A  to  B,  signal  17  cleared,  and  a 
train  is  on  some  part  of  this  route.  Then  the  latch  on  lever 
17  is  locked  so  that  it  cannot  be  lowered  in  the  normal  posi- 
tion (and  in  consequence  of  this  no  locking  will  be  released) 
until  the  train  has  passed  signal  4  ;  17  reversed  locks  9  re- 
versed, which  locks  10  reversed  ;  also  17  reversed  locks  7  re- 
versed, which  locks  8  normal;  also  4,  20  and  18  are  locked 


Fig.  2055.     Interlocking,  Single  and  Double  Track  Junction. 


a  derail  or  through  a  sharp  turnout  at  high  speed,  with 
disastrous  results.  Power  used  to  operate  switches  has  fre- 
quently crumpled  up  detector  bars  under  trains.  With  rail 
larger  than  the  85-lb.  section  the  ordinary  outside  detector  bar 
cannot  be  counted  upon  to  strike  the  tread  of  the  wheel,  and 
inside  detector  bars  (Figs.  1480  and  1598-1603)  for  various 
reasons  are  not  considered  desirable.  Thus  a  switch  or  derail 
may,  under  certain  conditions,  be  thrown  under  a  moving 


Fig.  2056.     Electric  Locking  for  Switches  and  Signals  Shown  in  Fig.  2055. 


train.  Furthermore,  detector  bars,  as  usually  installed,  are 
operated  on  a  false  principle ;  if  they  fail,  they  are  inoperative. 
To  overcome  these  and  other  difficulties,  electric  locking  has 
been  introduced.  It  may  be  considered  an  extension  of  the 
functions  of  the  track  circuit,  and  in  some  methods  of  appli- 
cation is  called  track  circuit  locking. 

As  applied  to  mechanical  interlocking  it  is  usually  quite 
simple.  It  involves  only  the  use  of  electric  locks  (Figs.  2801- 
2812)  on  the  latches  of  certain  lovers,  usually  those  of  the 
home  signals  ;  although,  if  the  protection  is  to  be  made  more 
complete,  they  are  applied  to  certain  special  route  levers  or 
to  regular  levers  that  can  be  used  as  route  levers. 

These  locks  are  controlled  by  circuits  passing  through  the 
contact  points  of  track  relays  in  the  various  sections  involved. 
This  control  is  usually  accomplished  through  the  medium  of 
an  indicator  (see  page  363)  ;  that  is,  the  track  relays  control 
the  indicator,  and  the  indicator  controls  the  lock.  This  Is 
done  in  order  to  give  a  visual  indication  of  the  condition  of 
the  track  section  and  not  compel  the  signalman  to  depend 
upon  watching  the  train  or  trying  his  levers.  Repeated  trials 
will  in  time  wear  out  the  dog  and  the  slot  of  the  lock.  The 
relative  protection  afforded  by  locking  signal  levers  and  route 
levers,  respectively,  may  be  understood  by  reference  to  Fig. 
2559,  which  shows  the  layout  of  an  interlocking  plant  having 
a  twenty-lever  machine.  If  the  latches  of  high  home  signals 
only  are  controlled  by  track  circuits,  protection  will  be  given 
only  to  trains  moving  in  the  established  direction  of  traffic  on 


normal  ;  therefore,  it  is  safe  for  the  train  to  proceed,  as  none 
of  these  functions  can  be  moved.  But  suppose  that  the  signals 
are  set  for  a  movement  from  B  to  A  ;  now  4  reversed  will  lock 
all  the  conflicting  and  opposing  functions,  but  it  has  no  lock 
on  its  latch,  and  therefore  no  track  circuit  protection.  This 
could  be  overcome  by  putting  locks  on  all  the  dwarf  signal 
latches,  but  this  is  considered  too  expensive.  Also  if  the  signal 
were  out  of  service  and  the  signalman  should  flag  a  train 
through  without  reversing  his  signal  lever,  there  would  be  no 
protection. 

Full  protection  can  be  provided  at  minimum  expense  by 
choosing  certain  levers  as  route  levers  and  locking  their  latches. 
There  are  the  following  possible  routes  in  the  present  case :  A-B, 
C-D,  D-B,  A-E,  C-E,  D-E,  E-F,  B-A,  B-C,  B-D,  E-A,  E-C,  E-D, 
F-E.  These  routes  may  be  so  grouped  together  that  from  A  to 
all  possible  points  can  be  considered  as  one  route ;  the  same  for 
B  and  E.  Now,  if  the  dog  locking  is  arranged  so  that  In  set- 
ting up  a  route  to  or  from  A  or  B,  9  must  be  thrown  last  be 
fore  the  signal,  and  to  or  from  E,  7  must  be  thrown  last  before 
the  signal,  then  9  or  7  reversed  will  lock  all  the  functions  in  the 
route  and  will  in  turn  be  locked  by  the  signal  lever.  Therefore, 
levers  9  and  7  are  the  only  ones  whose  latches  need  be  supplied 
with  locks.  These  locks  must  lock  the  latch  down  with,  the 
lever  reversed.  This  must  be  done  every  time  a  derail  or  lock 
lever  is  used  as  a  route  lever.  Frequently  when  a  switch  lever 
is  used  as  a  route  lever  the  lock  must  lock  the  latch  down  with 
the  lever  either  normal  or  reversed.  When  so  supplied  protec- 


Figs.  2057-2058 


INTERLOCKING. 


281 


tion  against  improper  movements  of  switches  and  derails  Is 
aftorded  without  reference  to  the  home  signal  levers,  no  matter 
what  route  is  being  used.  Whenever  a  lock  is  placed  on  a 
signal  lever  it  should  never  hinder  moving  the  lever  far  enough 
(o  cause  the  signal  to  assume  the  stop  position  (or  caution 
position  in  case  of  a  distant  signal),  because  it  should  always  be 
possible  to  move  the  lever  to  stop  a  train  in  case  of  emergency. 
Another  method  is  to  have  the  home  signals  locked  as  soon  as 
cleared,  and  released  only  when  a  train  has  reached  a  certain 


are  locked ;  that  is  to  say,  a  train  in  a  certain  route  locks 
switches  and  derails  in  conflicting  routes  only.  This  is  no  more 
than  dog  locking  is  designed  to  do,  except  that  it  holds  after 
the  signal  lever  has  been  put  normal,  until  the  route  is  clear. 

At  power  plants  controlled  otherwise  than  electrically,  lever 
locking  is  the  only  kind  that  can  be  economically  and  efficiently 


Fig.   2057.     Electric    Locking    Circuits   for    Single-Track   Crossing. 


point  within  or  beyond  the  interlocking  limits.  This  will  be 
discussed  later  in  connection  with  approach  locking. 

At  power  plants  with  electric  control  the  same  methods  as 
above  described  may  be  used ;  that  is,  electric  locks  on  the 
levers  may  be  used.  Usually  there  are  no  latches  or  latch  lock- 
ing at  these  plants,  consequently  the  lever  itself  must  be  locked. 
Another  difference  is  that  there  are  usually  no  separately  oper- 
ated facing  point  locks  at  power  plants ;  therefore  a  derail  or 
switch  lever  must  be  used  for  the  route  lever,  and  be  con- 
trolled by  the  electric  locking.  If  signal  levers  are  to  be  locked 
It  is  often  convenient  to  break  their  indication  circuits,  through 
relay  or  indicator  contacts,  thus  avoiding  the  necessity  of  an 
additional  electric  lock.  Also  with  the  same  effect,  the  con- 
trol circuits  of  switches  and  derails  are  broken  through  such 
contacts. 

If  the  indication  circuit  of  all  signals  concerned  is  broken 
while  a  train  is  occupying  the  route  or  section  of  route  gov- 
erned, the  protection  will  be  complete.  For  when  the  indication 
circuit  is  broken,  the  releasing  device  on  the  lever  cannot  act, 
and  the  lever  is  held  in  an  intermediate  position,  thus  locking 
all  opposing  and  conflicting  routes  as  if  it  were  at  full  re- 
verse. Usually,  however,  the  indication  circuits  of  the  high 
home  signals  only  and  the  control  circuits  of  the  switches  and 
derails  in  a  route  are  broken.  This  is  done,  because  if,  with 


applied.  Valves  and  their  controlling  apparatus  are  cumber- 
some and  expensive. 

Where  any  one  of  these  systems  is  applied  only  to  track 
sections  within  the  home  signal  limits  the  use  of  detector  bars 
can  hardly,  be  dispensed  with.  It  takes  an  appreciable  length 
of  time  for  a  track  relay  to  act,  and  the  indicator  and  lock 
consecutively  consume  equal  periods.  Therefore,  before  the  lock 
has  acted  it  may  be  possible  to  change  at  least  one  of  the 
switches  or  derails  in  the  route.  Consequently,  it  is  advisable 
to  have  a  detector  bar  at  the  entrance  to  each  high-speed  route, 
at  least. 

To  overcome  this  difficulty  and  to  better  prevent  any  change 
of  route  after  a  train  has  passed  the  distant  signal  at  clear, 


•OnB/ade 


Fig.    2058.     Electric    Locking    Circuits    for    Single-Track    Crossing. 


no  means  of  holding  the  switches,  a  signal  should  be  out  of 
order,  and  it  were  necessary  to  flag  a  train  through,  there 
would  be  no  protection  ;  this  for  the  reason  that  there  would 
be  nothing  to  compel  the  signalman  to  reverse  his  signal  lever, 
and  with  the  signal  lever  normal  the  route  would  not  be  locked. 
The  best  system  would  seem  to  be  a  combination  of  lever  locking 
and  circuit  control  ;  that  is,  to  break  the  high  home  signal  in- 
dication circuits  and  the  switch  and  derail  control  circuits  and 
lock  route  levers. 

In  another  system  of  electric  locking,  conflicting  rentes  only 


approach  locking  has  been  introduced.  This  is  an  arrangement 
of  circuits  whereby  the  lock  on  the  home  signal  or  route  lever 
latch  operates  when  a  train  approaches  the  interlocking  plant 
with  the  governing  signals  in  a  certain  position. 

Broadly,  there  are  in  use  two  systems :  In  one  the  lock  acts 
as  above  when  the  train  is  approaching  the  distant  signal  with 
the  home  signal  clear,  and  holds  until  the  train  has  reached  a 
point  within  or  beyond  the  interlocking  limits.  This  may  be 
modified  so  as  to  require  the  distant  signals  also  to  be  clear ; 
or  it  may  be  made  to  act  when  a  train  has  passed  the  distant 


282 


INTERLOCKING. 


Figs.  2059-2060 


signal  with  the  home  signal  clear.  In  the  other  system,  the 
route  is  locked  as  soon  as  the  home  signal  is  cleared,  regard- 
less of  whether  a  train  is  approaching  or  not.  Of  course,  in 
dealing  with  electrically  controlled  power  plants  the  above  may 
be  modified  so  as  to  break  control  and  indication  circuits  as 
already  described. 

Fig.  2056  shows  the  approach  and  other  locking  circuits  for 
the  mechanical  interlocking  plant  shown  in  Fig.  2055.  The 
system  is  that  described  for  Fig.  2055,  using  7  and  9  as  route 
levers,  and  the  first  of  the  approach  locking  systems. 

A,  B,   C,  D,   E  and  F  are  track  relays  operated  by  batteries 
G,  Gj,  etc.,   through  their  respective  track  sections  ;   a,  b,   c,   d 


fore  f  is  made  to  break  the  shunt  around  the  contact  point 
of  indicator  b  in  the  circuit  of  lock  H.  Lock  H  cannot  be  con- 
trolled by  this  indicator  in  all  cases,  because  if  this  were 
done  a  train  on  the  eastbound  track  would  prevent  changing 
a  route  on  the  westbound  track,  when  it  would  be  proper  to 
do  so. 

One  modification  that  is  frequently  made  is  to  put  the  cir- 
cuit controllers  on  the  distant  signal  levers.  When  this  is  done 
the  approach  locking  takes  effect  only  when  the  distant  signal 
is  clear  with  a  train  approaching.  In  the  plant  under  consid- 
eration the  distant  signals  are  assumed  to  be  power  operated 
without  separate  levers.  Sometimes  the  circuits  for  the  ap- 


Fig.  2059.     Approach   Locking  for  Single   Switch  on  a   Single-Track  Main   Line. 


and  e  are  indicators ;  a  is  controlled  by  F,  b  by  E,  c  by  A  and 
D,  d  by  C  and  e  by  B.  H  is  a  lock  on  the  latch  of  lever  9,  and 
I  is  a  lock  on  latch  of  lever  7  ;  f,  g,  h  and  i  are  circuit  con- 
trollers operated  by  levers  8,  2,  17  and  20,  respectively.  Sup- 
pose a  train  to  be  approaching  on  the  branch  line  with  the 
route  lined  up.  Until  the  first  track  battery  G  is  passed  the 
route  can  be  changed  at  will,  but  as  soon  as  G  is  passed  relay 
C  opens,  thereby  de-energizing  indicator  d,  relay  e'  and  lock 
H.  For,  when  No.  17  was  reversed,  circuit  controller  h  was 
opened  and  the  shunt  on  the  point  of  d  and  e  removed.  Thus 
lover  9  is  locked  reversed  and  the  route  cannot  be  changed. 
Lever  9  remains  locked  until  the  train  has  passed  beyond 
signal  4,  as  by  its  passage  relays  D  and  A  are  successively 
opened,  thereby  de-energizing  indicator  c.  This  keeps  the  cir- 
cuit for  lock  H  open.  The  signalman  is  prevented  from  restor- 
ing his  lock  (by  putting  his  signal  levers  normal)  while  a  train 


proach  indicators  are  broken  through  normally  closed  circuit 
controllers  on  the  home  and  distant  signal  arms,  so  that  If 
either  should  fail  to  assume  the  full  stop  position  when  the 
levers  are  put  normal,  the  route  would  remain  locked. 

Fig.  2057  shows  the  circuits  for  approach  and  other  locking 
at  a  single  track  crossing.  Here  a  separate  circuit  is  run  for 
each  lock  through  circuit-breakers  on  the  distant  signals,  so 
that  the  locking  will  not  release  until  the  distant  signal  arm 
is  in  full  horizontal  position.  The  locks  act  on  the  latches  of 
the  home  signal  levers  to  which  are  also  attached  the  shunt 
circuit  controllers  (shown  just  beneath  the  indicators).  These 
circuit  controllers  are  closed  only  when  the  levers  are  normal 
and  the  latches  down.  The  contacts  A,  B,  C  and  D  represent 
hand  releases  (usually  some  form  of  time-release,  Figs.  2843- 
2853)  which  are  used  when  it  is  necessary  to  change  a  route 
that  has  been  given  to  a  train. 


Fig.  2060.     Approach  Locking  for   Single   Switch   on  a  Single-Track   Main   Line. 


Is  approaching  by  the  special  stick  wiring  of  the  relays  a' 
and  e'  which  control  the  locks  with  the  "home"  indicators  b  and 
c.  They  are  controlled  by  the  approach  indicators  a,  d  and 
e,  and  break  their  own  circuits.  They  can  be  restored  only 
through  the  back  contacts  on  their  respective  home  indicators 
when  a  train  is  in  the  home  section.  Suppose  the  train  ap- 
proaches without  the  signals  clear ;  in  this  case  the  route 
would  not  be  locked  and  the  signalman  could  hold  the  train 
at  the  home  signal  until  ready  for  it  to  proceed.  At  the  same 
time  he  could  allow  another  train  to  use  any  of  the  routes 
within  the  plant.  The  purpose  of  circuit  controller  f  on  lever  8 
is  this :  Suppose  that  the  route  through  the  crossover  re- 
versed is  set  up  for  an  eastbound  movement.  Now,  to  be  safe, 
lever  9  must  be  controlled  by  relay  E  (through  indicator  b)  ; 
otherwise  it  would  be  possible  to  move  any  of  the  switches  ex- 
cept the  crossover,  until  the  train  had  passed  through  the 
crossover,  onto  the  track  circuit  controlling  relay  A.  There- 


Fig.  2058  shows  the  same  crossing  wired  with  the  indicator 
circuit  through  a  circuit  controller  on  the  distant  signal  arm. 
Here  the  approach  indicator  contact  opens  when  the  distant 
signal  is  cleared,  whether  a  train  is  approaching  or  not.  The 
locks  act  as  in  Fig.  2057,  but  the  circuit  controllers  F,  G,  H 
and  I  need  not  be  attached  to  the  latches.  They  can  work  with 
the  home  signal  levers.  The  stick  relays,  X,  Y,  hold  the  lock 
circuits  open  during  the  passage  of  a  train,  whether  the  signal 
levers  are  restored  or  not.  These  circuits  are  suitable  for  a 
power  plant  in  which  control  and  indication  circuits  are  broken, 
and  there  are  no  locks  on  the  levers.  At  such  a  plant  stick 
relays  are  necessary  (as  there  is  no  latch  locking),  unless  the 
section  of  lever  stroke,  after  indication  has  been  received,  is 
long  enough  to  operate  a  circuit  controller.  At  a  plant  where 
the  home  signal  lever  latches  are  locked  stick  relays  are  not 
needed,  as  the  shunt  circuit  controller  can  be  made  to  be  closed 
only  when  the  lever  is  normal  with  the  latch  down,  as  in  Fig. 


Figs.  2061-2062 


INTERLOCKING. 


283 


284 


INTERLOCKING. 


Figs.  2063-2064 


2057,  and  this  condition  will  not  occur  until  the  lock  is  re- 
leased. At  power  plants  the  point  at  which  the  lever  is  held 
for  indication  can  sometimes  be  used  as  the  latching  point,  as 
above.  But  in  any  case  where  the  shunt  circuit  controller  is 
operated  by  a  lever  other  than  the  one  upon  which  the  lock 
acts,  a  stick  relay  must  be  used. 

In  a  power  plant  using  the  first  modification  described  for 
Fig.  2056,  but  without  lever  locks,  indicators  are  provided, 
controlled  by  track  circuits  in  the  usual  manner,  as  shown 
in  Fig.  2059.  In  this  diagram  A,  B  and  C  are  track  relays  ; 
a,  b  and  c  indicators,  a'  and  c'  stick  relays,  b'  a  secondary 
relay  controlled  by  indicator  b,  and  E  and  F,  contacts  on  dis- 
tant signal  levers  1  and  12  respectively.  The  approach  locking 


NOTE  TO  FIGS.  2063-2068. 

Insulated   switch    rods    to   be    used    on   all 
circuit  limits. 

Insulated   connections  to   be  used  on  all 

Resistances  : 

Indicators     

Repeating    relays     

Electric    locks     

Electric    slots     

Track    relays    

Indicator  and  relay  symbols  : 


switches   in  track 
detector   bars. 


.1000  ohms 
,1000  ohms 
.  500  ohms 
,  100  ohms 
5  ohms 


Is  accomplished  by  breaking  the  indication  circuit  of  the  home 
signal  governing  the  route,  through  the  front  point  of  the 
stick  relay,  controlled  by  the  circuit  controller  on  the  distant 
signal  lever  in  parallel  with  a  front  point  on  the  approach 
Indicator.  In  this  system,  unless  the  distant  signal  has  been 
cleared,  it  is  possible  to  put  a  home  signal  lever  normal  at  any 
time,  provided  a  train  is  not  in  the  section  governed.  This 
does  away  with  delay  in  case  the  wrong  route  has  been  lined  up. 
The  stick  relay  is  restored  by  a  back  contact  on  relay  b'.  With 
this  system  there  is  no  delay  due  to  the  locking  in  case  th<.- 
signalman  neglects  to  put  his  home  signal  lever  normal  promptly 
behind  each  train.  When  the  distant  signal  is  cleared  with  a 
train  approaching,  the  home  signal  indication  is  withheld  until 


1A,  2A,  etc. — Block  indicators. 
IP,    2P,   etc. — Approaching  indicators. 
Al,  X2,  Yl,   etc. — Track   relays. 
IV,    2V,   etc. — Signal    relays. 
A1Z,  BIZ,  etc. — Repeating  relays. 

Wire  numbering,  these  symbols  indicate  things  controlled  : 
Track  Nos.   1A-2A,   etc. — Block  indicators. 

"      IP,    2P,      etc. — Approach   indicators. 
"          "      1.T,   2J,  etc. — Distant  signals. 
"          "      A1Z,   BIZ,   etc. — Repeating  relays. 

1SK — Electric  Jock   on  hand  switch. 
Lever  Nos.   4K,   14K,   etc. — Electric  locks. 
The   consecutive  wire   number  follows  the  letter  of  the   sym- 
bol   (the  last  letter  in  combined  symbols). 


Fig.  2065 


INTERLOCKING. 


285 


the  train  has  passed  out  of  the  home  section.     The  current  sup-  The  second  system,  wherein  the  home  signal  is  locked  as  soon 

ply  to   the   switch  bus   bar   is  cut  through   a   contact   on   relay       as    its    lever    is   reversed,    is    used    more    extensively    at    power 
b'   in   order  to   provide   detector   locking  for   a  movement  from       plants  electrically  controlled    (see  Fig.   2076).      In  this  system 


SMS-WS 


signal  10.     With  this  system  signals  can  be  tested  at  any  time       the  Indication  circuits  of  the  home  signals  are  normally  broken 
without  necessitating  the  use  of  the  hand  release.  through  open  back  points  of  indicators,  controlled  by  the  home 


286 


INTERLOCKING. 


Fig.  2066 


track  circuits,  so  that  the  stroke  of  the  signal  lever  to  normal 
cannot  be  completed  without  using  a  hand  release  unless  a 
train  occupies  the  track  section.  In  other  words,  if  the  signal- 
man clears  a  home  signal,  he  cannot  completely  restore  his 


as  shown  in  Fig.  2060.  In  this  figure  indicators  a,  b  and  c 
are  controlled  by  track  relays  A,  B  and  C,  respectively,  a'  and 
c'  are  stick  relays,  b'  is  a  secondary  relay  controlled  by  indica- 
tor b,  and  E  and  F  are  circuit  controllers  on  the  distant  signal 


lever  In  the  usual  way  unless  a  train  Is  within  the  interlock- 
ing limits  on  the  track  governed.  Additional  approach  locking 
is  accomplished  by  breaking  the  power  circuits  of  the  switches 
and  derails  In  the  route  governed  through  points  on  stick  relays, 


levers.  The  stick  relays  are  controlled  by  the  circuit  con- 
trollers on  the  distant  signal  levers,  in  parallel  with  the  front 
points  of  indicators,  a  and  c,  which  are  in  turn  controlled  by 
the  approach  track  circuits.  The  stick  relays  are  restored  by 


Figs.  2067-2068 


INTERLOCKING. 


287 


Figs.    2067-2068.     Electric    Locking    Circuits,    North    Philadelphia.     Pennsylvania   Railroad. 


288 


INTERLOCKING. 


Figs.  2069-2071 


back  contacts  on  relay  b.  The  current  supply  to  the  switch 
bus  bar  is  controlled  by  all  three  relays,  a',  b'  and  c',  provid- 
ing electric  detection.  Hand  releases  D  are  provided  in  Figs. 
2059-2060  for  use,  as  explained  in  connection  with  Figs.  2057 
and  2076.  To  compel  the  signalman  to  restore  the  release  to 
its  normal  position  after  reversing  it,  the  return  for  relay  b' 
is  In  each  case  cut  through  a  normal  contact  on  the  hand  re- 
lease. 

Some  disadvantages  of  locking  the  route  by  reversing  the 
signal  levers,  regardless  of  whether  or  not  a  train  is  approach- 
ing, are  as  follows :  1.  It  is  impossible  to  test  signals  easily. 
Every  time  the  lever  is  reversed  it  locks  itself.  This  is  partic- 
ularly annoying  at  mechanical  plants  in  winter,  when  it  is  nec- 
essary to  move  the  signals  frequently  to  keep  them  from  freez- 
ing. 2.  It  interferes  with  the  flexibility  of  operation.  If 


of  relay  B4,  wire  47K6,  to  wire  47K.  This  also  cuts  out  the 
front  contact  of  indicator  4P  when  relay  B4  is  de-energized. 
The  lock  is  de-energized  with  train  in  approach,  distant  or 
home  track  section,  also  with  the  distant  signal  clear,  and  is 
not  again  energized  until  train  has  entered  section  B4,  since 
relays  Y4  and  X4  control  the  indicator  4P.  The  object  of  the 
back  point  on  relay  B4  is  to  allow  the  signalman  to  put  lever 
47  normal,  supposing  one  train  is  standing  in  section  A4  and 
another  train  in  either  the  approach  or  distant  sections.  If 
the  first  train  should  pass  to  section  B4,  it  would  be  proper 
to  let  the  second  train  through  crossover  32  onto  track  3,  but 
the  indicator  4P  would  be  de-energized  and  therefore  this  back 
contact  on  relay  B4  is  necessary  to  permit  the  route  to  be 
changed.  The  slow  release  also  acts  as  a  shunt  around  the 
contact  on  indicator  4P.  It  should  be  noted  that  the  slow 


Fig.    2069.     Circuits    for   Electro-Pneumatic   Switch    Movement   Without  Detector   Locking. 
<Snap  -Switch 


Fig.    2070.     Circuits    for    Electro-Pneumatic  Switch   Movement    With    Detector   Locking. 


rt1- 

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TF 

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T>rr0              "TT                    —  T7:  :  — 

B^     IW                !4r                            & 

L        "             B 

o-ggr 

o32                                                   r 

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n       f* 

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F',  G — Signal-lever  circuit  controller. 

Fig.    2071.     Typical    Route    and    Detector    Locking    Circuits    for    Electro-Pneumatic    Interlocking    Plant.    Dela- 
ware,  Lackawanna   &  Western. 


the  wrong  route  is  lined  up  by  mistake,  it  locks  itself,  thereby 
causing  delay. 

It  will  be  observed  that  circuits  for  the  control  of  routes 
are  so  arranged  that  if  any  part  of  the  apparatus  should  fail 
or  become  deranged,  the  locking  would  act  and  hold  the  route, 
or  possibly  the  whole  plant,  locked  until  the  trouble  is  repaired. 
This  is  the  governing  principle  in  signaling.  If  anything  fails, 
a  dangerous  condition  must  not  result. 

Figs.  2063-2065  show  electric  locking  at  Denholm,  on  the 
Pennsylvania  Railroad.  This  is  a  mechanical  interlocking  plant. 
The  locking  circuits  for  the  route  governed  by  signal  47  may 
be  considered  as  typical.  Circuit  for  lock  47  :  From  battery 
at  distant  signal  through  circuit  breakers  on  signal  arms,  wire 
46K-47K1,  front  point  of  relay  A4,  wires  47K3  and  47K4,  from 
point  of  indicator  4P,  wires  47K5  and  47K,  circuit  breaker  on 
tappet,  through  lock  to  common.  A  branch  47K7  is  taken  off 
wire  47K3,  through  slow  release  to  wire  47K,  thereby  cutting 
out  the  contact  on  indicator  4P  with  instruments  in  normal 
position.  Another  branch  is  taken  off  wire  47K3  to  back  point 


release  and  the  back  contact  on  relay  B4  are  inoperative  with 
a  train  standing  in  section  A4,  in  other  words  they  act  only 
on  the  approach  locking.  The  track  circuit  in  section  A4  is  a 
detector  circuit  inasmuch  as  it  locks  the  latch  of  lever  47  up 
with  the  lever  normal,  thereby  preventing  movement  of  any 
of  the  switch  or  facing  point  lock  levers  for  the  route  gov- 
erned up  to  signal  40.  Relays  B4  and  B3  control  a  lock 
on  facing  point  lock  lever  17,  locking  this  lever  reversed.  This 
acts  as  a  detector  lock  when  a  train  is  standing  in  either 
circuit. 

Figs.  2061-2062  show  electric  locking  circuits  in  use  at  Irvine- 
ton,  Pennsylvania  Railroad. 

This  is  a  mechanical  interlocking  plant  with  slotted  signals. 
The  circuits  for  route  governed  by  signals  23  and  13  may  be 
considered  as  typical.  The  circuit  for  lock  23  starts  from  the 
battery  at  right  of  Fig.  2062,  and  passes  through  the  circuit 
controller  on  the  distant  signal,  wire  13K-23K1,  from  contact 
on  relay  A2,  wire  23K2,  front- contact  on  indicator  2P,  wire 
23K,  circuit  controller  on  tappet  (lever  23),  lock  23  to  com- 


Figs.  2072-2074 


INTERLOCKING. 


289 


mon  and  back  to  battery.  Two  parallel  circuits  are  run  around 
the  front  contact  on  indicator  2P,  one  through  the  back  point 
on  indicator  2A,  the  other  through  the  slow  release. 

The  circuit  for  indicator  2P  starts  from  the  same  battery 
and  passes  through  the  front  contacts  of  relays  Y2  and  X2, 
wire  2P,  indicator  2P,  to  common. 

The  circuit  for  indicator  2A  starts  from  the  main  battery 
and  passes  through  the  front  contact  of  relay  A2,  wire  2A1, 
front  contacts  of  relays  B2  and  Cl,  wires  2A2  and  2A5,  cir- 
cuit controller  on  lever  23,  wires  2A6  and  2A,  indicator  2A  to 


switch  17  reversed,  while  another  train  is  standing  between 
signals  27  and  13.  A  tap  is  taken  off  from  wire  2A6,  through 
the  second  circuit  controller  on  lever  23,  to  the  slot  on  signal 
23  (not  shown). 

Lock  23  is  de-energized  with  a  train  in  the  approach,  distant 
or  home  circuits,  or  with  distant  signal  clear.  It  should  be 
noted  that  indicator  2A  is  controlled  beyond  the  limits  of 
section  A2  and  that  its  back  point  picks  up  the  lock,  provided 
the  distant  signal  is  normal  and  no  train  is  in  the  home  cir- 
cuit, A2.  This  indicator  remains  de-energized  until  lever  23 


I* 


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LJ 

Iwv 

Fig.  2072.     Typical  Circuits  for  Approach  Indicator  and  Distant  Repeater   (Automatic  Signals  are  Overlapped). 

Electric  Zone,  New  York  Central  &  Hudson  River. 


Approach 

r* 

^ 

Ha/fffererse 
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or/net/  one/  ftererse  Lock 

Track      ' 
ffe/at/     • 

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Fig.  2073. 


n  * 

Typical  Circuits  for  Approach  Locking  and  Electric  Detection  at  an  Electric  Interlocking  Plant.   Elec- 
tric Zone,  New  York  Central  &  Hudson  River. 


Fig.  2074.     Electric  Locking  Circuits,  With  Electro-Mechanical  Hand   Release  for  Electric  Interlocking  Plant. 


common.  As  soon  as  the  indicator  is  energized  its  front  arma- 
ture contact  forms  a  shunt  direct  from  wire  2A2  to  2A,  so  that 
the  Indicator  will  remain  energized  after  the  circuit  controller 
on  lever  23  is  opened,  in  the  same  manner  as  a  stick  relay. 
This  "stick"  feature  makes  it  necessary  for  lever  23  to  be  put 
Into  the  full  normal  position  after  each  train.  A  shunt  circuit 
through  wire  2 A3,  circuit  controller  on  lever  17,  and  wire 
2A4,  bridges  the  contact  on  relay  B2  when  17  Is  reversed. 
This  Is  to  allow  a  train  to  be  moved  from  signal  23  through 


is  fully  normal.  This  extends  the  releasing  section,  giving  the 
signalman  more  time  to  restore  his  lever  after  a  train  passes, 
in  case  a  following  train  has  entered  track  circuits  Y2  or  X2, 
and  is  to  proceed  on  a  different  route.  Leaving  the  signal 
lever  reversed  will  not  cause  trouble,  because  the  slot  circuit 
is  then  de-energized  and  the  signal  will  remain  In  the  stop 
position  until  the  lever  is  put  normal  and  again  reversed. 

The  lock  on  lever  13  is  controlled  through  wire  13K2,  which 
taps  off  from  wire  13K-23K1,  In  substantially  the  same  manner 


2QO 


INTERLOCKING. 


Fig.  2075 


as  lock  on  23.  Thus  the  advance  and  home  signal  lever  latches 
are  both  locked  up  (lever  normal)  if  these  signals  have  been 
cleared  for  an  approaching  train.  The  slow  releases  perform 
the  same  function  as  the  back  point  on  the  home  or  advance 
indicators. 

Figs.  2066-2068  show  electric  locking  circuits  at  North 
Philadelphia,  Pennsylvania  Railroad.  This  is  an  electro-pneu- 
matic plant.  Both  approach  and  detector  locking  is  provided. 
The  approach  locking  and  release  circuits  are  similar  to  those 
shown  for  Irvineton  (Figs."  2061-2062).  Locking  of  levers  is 
accomplished  through  the  indication  magnets.  The  track  cir- 
cuits are  supplied  with  current  from  storage  cells.  The  de- 
tector locking  is  accomplished  as  shown  in  Fig.  2070  by 
breaking  the  switch  lever  circuits  through  track  or  repeating 
relays,  or  indicators  for  the  sections  in  which  the  switch  oc- 
curs. The  circuit  for  switch  5  shows  the  simple  arrangement ; 
most  of  the  other  switches  are  provided  with  route  locking 
controlled  through  stick  relays  ;  No.  9  may  be  considered  as 
typical. 

In  electro-pneumatic  interlocking  for  indication  purposes  a 
switch  lever  is  unlocked  near  the  end  of  the  stroke  to  allow 
a  movement  to  the  extreme  position,  whereas  for  electric  de- 
tection the  lever  is  unlocked  to  allow  a  movement  starting  from 
the  extreme  position.  As  these  two  lockings  are  never  required 
at  the  same  time  they  can,  in  the  electro-pneumatic  machine, 
be  secured  by  use  of  the  same  apparatus  through  a  modification 
of  the  lock  segment  and  latch,  and  an  addition  to  the  circuits 
controlling  the  normal  and  reverse  indication  magnets. 

The   standard   form    of    segment    is    shown   in    Fig.    1964,   and 


d  is  closed.  In  the  extreme  normal  position,  as  shown  in  the 
diagram,  the  only  current  that  can  energize  N  must  pass 
through  the  contact  on  the  track  relay  and  similarly,  with  the 
lever  in  extreme  reverse  position,  current  for  R  must  pass 
through  the  same  relay  contact  and  controller  d.  The  circuit 
breakers  e  and  d  are  the  same  as  the  roller  band  controllers 
employed  for  signal  circuits.  The  dog  S  engages  with  the  arma- 
ture of  R  when  the  lever  is  reversed  in  the  same  manner  as 
A  with  K  when  normal. 

Fig.  2071  shows  typical  electric  locking  circuits  used  at  the 
Hoboken  Terminal  of  the  Delaware,  Lackawanna  &  Western, 
which  provide  route  locking  and  also  electric  detection.  The 
track  is  divided  into  convenient  sections  between  signals  so 
as  to  allow  maximum  freedom  of  lever  movements  ;  a,  6  and  c 
are  track  relays  for  circuits  A,  B  and  C,  respectively.  Each 
of  these  track  relays  controls  a  repeating  relay,  a',  V  and  c', 
which  simply  repeat  the  action  of  the  track  relays.  Relays  a' 
and  c'  control  stick  relays  in  connection  with  the  circuit  con- 
trollers F  and  G,  on  the  signal  lever.  Suppose  a  train  to  be 
approaching  signal  S ;  to  permit  it  to  proceed  the  signalman 
reverses  the  signal  lever  to  the  left,  opening  circuit  controller 
G,  but  keeping  F  closed.  As  soon  as  the  train  enters  section 
A  relays  a  and  a'  are  de-energized ;  when  a'  opens  (G  already 
being  open)  stick  relay  E  is  de-energized,  opening  the  circuit 
for  the  lock  magnet  N  on  the  switch  lever.  As  the  train  passes 
from  section  A  to  section  B  the  relay  b'  is  de-energized,  hold- 
ing the  circuit  for  lock  N  open.  Relay  E  picks  up  as  soon  as 
the  rear  of  the  train  clears  section  A.  When  the  train  enters 
section  C,  relay  c'  opens,  but  as  F  is  still  closed  the  stick  re- 


Fig.  2075.     Typical  Electric  Approach  Locking  Circuits,  With  Electric  Hand   Release  for  Electric  Interlocking. 


its  operation  indicated  in  Fig.  2069.  This  differs  from  the  ele- 
mentary form  shown  in  Figs.  1972-1975,  in  the  use  of  the  lug 
M  engaged  by  the  reverse  indication  armature  when  energized 
(and  also  one  for  the  normal  armature).  In  reversing  the 
switch,  the  magnet  R  should  remain  de-energized  until  lug  M 
passes  the  point  where  the  armature  of  R  could  engage  it.  If 
for  any  reason  (such  as  a  cross  In  circuits,  etc.)  R  should  be 
energized  improperly,  its  armature  would  engage  with  M  and 
prevent  further  movement  of  the  lever.  This  lug  also  operates 
to  prevent  an  indication  magnet  from  acting  falsely  through 
residual  magnetism,  and  also  from  being  blocked  or  "plugged" 
by  a  careless  repairman. 

The  modified  form  of  segment  is  shown  in  Fig.  1965  and 
its  operation  in  Fig.  2070.  The  armature  K  of  the  normal 
magnet  N  engages  one  side  of  the  dog  A,  with  the  lever  in 
the  extreme  normal  position ;  in  other  words,  it  engages  for 
detector  locking  purposes  the  other  side  of  the  same  dog  which 
is  engaged  for  indication  purposes  during  a  movement  of  the 
lever  from  reverse  to  normal.  The  additions  to  the  circuit  in- 
clude the  wires  B  and  p,  passing  through  a  front  contact  on 
the  track  relay,  and  the  lever  circuit  controllers  e  and  d,  a 
lever  latch  circuit  controller  H  also  being  added  for  the  pur- 
pose of  reducing  the  consumption  of  the  current  when  it  Is 
not  required. 

With  the  lever  in  the  extreme  normal  position  shown  in 
Fig.  2070,  the  detector  lock  circuit  starts  from  battery  and 
passes  through  wire  B,  front  contact  on  the  track  relay, 
wire  p,  circuit  controller  e,  magnet  N,  latch  contact  H,  to 
common ;  thereby  energizing  N,  and  raising  K  from  engage- 
ment with  A,  which  unlocks  the  lever.  The  first  movement  of 
the  lever  opens  e;  controllers  d,  g  and  f  remain  unaffected 
until  last  portion  of  the  stroke,  when  g  and  f  are  reversed  and 


lay  (directly  above  relay  c')  remains  closed,  and  as  soon  as 
the  rear  of  the  train  leaves  section  B,  relays  b  and  6'  are 
energized,  and  the  circuit  for  lock  N  closed.  If  the  switch 
Is  reversed  the  lock  R  is  in  circuit  'Instead  of  N  (see  Fig. 
2070).  In  a  movement  in  the  opposite  direction  the  lower 
stick  relay  would  be  de-energized  and  E  would  remain  ener- 
gized. Thus  circuits  are  provided  to  lock  all  switches  in  the 
route  when  a  train  passes  the  governing  signal  at  clear.  The 
switches  remain  locked  until  the  train  has  passed  over  them 
or  has  backed  off  the  route.  Each  switch  is  released  as  soon 
as  a  train  has  cleared  the  fouling  point.  Thus  a  route  cannot 
be  changed  ahead  of  a  train,  but  may  be  changed  as  soon  as  the 
rear  of  the  train  has  passed.  The  contact  1  is  operated  by 
the  switch  lever  latch  in  the  same  manner  as  H  in  Fig.  2070. 
The  electric  lamp  L  is  connected  in  multiple  with  the  lock 
magnets.  It  is  placed  just  below  the  lever  as  shown  in  Fig. 
2616,  and  is  lighted  while  the  switch  is  free  to  be  moved,  but 
it  is  extinguished  when  the  switch  is  locked  by  the  presence  of 
a  train. 

For  electric  locking  circuits  used  in  connection  with  the 
electro-pneumatic  push  button  machine,  see  Fig.  2003.  For 
electric  locking  circuits  for  drawbridge  protection,  used  with 
the  electro-pneumatic  interlocking  machine,  sec  Figs.  2014-2016. 
In  Fig.  2080  is  shown  an  arrangement  of  electric  locking 
circuits  used  at  interlocking  plants  protecting  simple  crossings. 
The  track  circuit  is  normally  open.  The  track  battery  supplies 
not  only  the  track  circuit,  but  also  a  10-ohm  stick  relay  whose 
circuit  is  carried  through  controllers  on  the  home  signal  levers 
so  that  the  reversal  of  any  one  of  them  will  de-energize  the 
stick  relay.  The  stick  relay  cannot  again  pick  up  until  all 
the  home  signal  levers  are  normal  and  the  track  relay  has  been 
energized  by  the  presence  of  a  train.  The  stick  relay  and  the 


Fig.  2076 


INTERLOCKING. 


291 


track  relay  both  control,  through  a  front  and  back  contact, 
respectively,  the  circuit  of  the  two  electric  locks  which  act  on  the 
derail  levers.  The  circuits  for  these  two  locks  are  also  carried 
through  normally  open  floor  pushes  in  order  to  economize  in 
current.  A  push  button  is  provided  to  energize  the  track  relay 
and  release  the  locking  in  case  it  becomes  necessary  to  change 
a  route  that  has  been  set  up ;  but  the  push  button  will  not 
release  the  locks  unless  the  signals  are  all  in  the  stop  position. 
Fig.  2072  shows  an  approach  indicator  and  distant  signal 
.repeater  for  an  interlocking  plant.  In  this  case  the  exterior 
circuits  are  energized  by  alternating  current.  The  approach 
indicator  is  controlled  by  a  circuit  from  the  transformer  at 
the  extreme  left,  through  a  normally  closed  circuit  control'er 
on  the  automatic  home  signal,  the  track  relay  point  at  the 
distant  interlocked  signal,  the  indicator,  to  common.  A  back 
point  on  this  indicator  closes  a  local  bell  circuit.  The  indica- 
tor circuit  is  not  run  through  a  circuit  controller  on  the  inter- 
mediate automatic  signal  because  the  circuits  for  these  signals 


another  is  approaching.  This  relay  is  controlled  by  the  home 
track  relay.  No  provision  is  made  for  shunting  out  the  distant 
repeater  for  the  reason  that  should  the  distant  signal  stick 
clear  a  train  might  accept  it  and  not  be  able  to  stop  at  the 
home  signal.  In  such  a  case  it  would  be  dangerous  to  have 
any  other  than  the  high  speed  route  set  up.  Lock  No.  4  acts 
on  the  switch  lever,  locking  it  in  either  full  stroke  position. 
This  lock  is  controlled  by  the  repeating  relay  so  that  a  train 
in  the  home  circuit  locks  the  switch  in  either  the  normal  or 
reverse  position,  as  the  case  may  be.  It  is  not  released  until  the 
train  has  passed  off  the  track  circuit. 

Another  arrangement  of  circuits  for  approach  locking  is 
shown  in  Fig.  2075.  Here,  as  in  Fig.  2074,  no  indicators  are 
used.  The  lock  is  controlled  by  a  circuit  controller  on  the  dis- 
tant signal  lever,  a  stick  relay,  and  the  normal  contact  of  the 
hand  release.  The  stick  relay  is  controlled  by  its  own  point 
and  two  parallel  circuits,  one  through  the  approach  track  relay, 
the  other  through  a  second  circuit  controller  on  the  distant 


ommon. 


when  S/gvrar/ te  C/ecrr. 


Fig.  20/6.     Typical   Circuits  for  Electric   Interlocking.     Chicago   &  North-Western. 


are  overlapped.  Therefore,  the  indication  will  be  maintained 
for  both  sections  by  the  one  circuit  controller.  The  repeater  is 
operated  by  a  normally  closed  circuit  controller  on  the  distant 
signal  arm. 

Fig.  2073  shows  how  the  above  instruments  are  made  use  of 
in  approach  and  detector  locking  at  an  electric  interlocking 
plant.  The  half-reverse  lock  (No.  2)  holds  the  home  signal 
lever  against  the  indication  stop  when  being  moved  to  the 
normal  position.  This  lock  is  controlled  by  the  approach  indi- 
cator and  the  repeater.  If  lever  No.  2  has  been  reversed  and 
the  home  and  distant  signals  cleared,  a  train  approaching 
within  a  mile  of  the  distant  signal  will  de-energize  the  lock 
and  prevent  lever  2  from  assuming  the  full  normal  position. 
Flowever,  it  may  be  moved  far  enough  to  put  the  signal  at  stop. 
It  will  be  noticed  that  the  notch  is  square  on  one  side  and 
sloped  off  on  the  other ;  this  is  to  allow  the  lever  to  be  reversed 
at  any  time.  There  are  two  shunt  circuits  around  the  contact 
of  the  approach  indicator,  one  through  the  screw  release,  the 
other  through  the  back  point  of  the  repeating  track  relay. 
Thus  by  working  the  release  the  approach  indicator  point  can 
be  shunted  out.  The  mechanical  action  of  this  release  will  be 
considered  in  connection  with  Fig.  2074.  It  is  to  be  used  if 
a  wrong  route  has  been  set  up  by  mistake,  and  a  train  for  an- 
other route  is  waiting  at  the  home  signal.  The  back  point  of 
the  repeating  relay  performs  the  same  function  as  the  release 
when  the  relay  is  de-energized.  This  is  to  permit  the  lever  to 
be  fully  restored  to  the  normal  position  preparatory  to  setting 
up  a  new  route,  if  one  train  has  passed  the  home  signal  and 


signal  lever.  It  is  restored  either  by  a  back  point  on  the  ad- 
vance track  relay  through  front  contact  on  the  home  track 
relay,  or  by  the  upper  contact  of  the  hand  release.  The  lock  Is 
de-energized  by  the  reversal  of  the  distant  signal  lever.  This 
opens  one  of  the  stick  relay  circuits  also,  so  that  a  train  In 
the  approach  section  will  open  the  stick  relay.  The  stick  relay 
will  remain  open  until  the  train  has  entered  the  advance  cir- 
cuit. This  circuit  restores  the  lock,  whether  a  second  train  is 
approaching  or  not,  provided  the  distant  signal  lever  has  been 
put  normal.  With  this  circuit  a  route  may  be  lined  up  and 
everything  put  normal  again,  provided  no  train  is  approaching, 
without  using  the  hand  release.  This  could  not  be  done  with 
the  circuits  in  Fig.  2074.  The  release  used  in  Fig.  2075  is 
entirely  electrical.  The  first  turns  break  the  lock  circuit 
while  the  last  close  the  stick  relay  circuit.  It  is  necessary  to 
restore  it  to  its  normal  position  before  the  lock  can  pick  up 
and  the  route  be  released.  The  lock  is  used  to  hold  the  signal 
lever  in  the  "half  reverse"  position,  as  in  Fig.  2073,  so  that 
the  signal  itself  may  be  put  in  the  stop  position  at  any  time 
in  case  of  emergency. 

Route  and  detector  locking  circuits  for  a  General  Railway 
Signal  Company's  electric  interlocking  plant  are  shown  In 
Fig.  2076.  The  locking  is  secured  by  cutting  the  signal  indica- 
tion circuit,  as  explained  in  connection  with  Figs.  2059-2060. 
but  on  account  of  the  "dynamic"  indication  current  being  pres- 
ent for  only  a  short  time  after  the  signal  mechanism  has  as- 
sumed its  normal  position,  the  circuit  arrangement  is  somewhat 
different  from  that  shown  in  these  illustrations. 


2Q2 


INTERLOCKING. 


Figs.  2077-2078 


The  switch  bus  bar  is  divided  into  sections,  each  section 
supplying  current  to  the  switches  in  one  route  only.  Reversal 
of  the  signal  lever  energizes  the  slot  A  and  clears  the  signal, 
through  contacts  L.  The  slot  circuit  is  as  follows :  From  the 
signal  bus  bar  through  contact  L,  indication  magnet  H,  binding 
post  Q,  lower  left  hand  contact  on  screw  release  F,  upper  con- 
tact on  track  relay  P,  slot  magnet  A,  to  common.  If,  after 
the  signal  is  cleared,  the  lever  is  moved  toward  normal,  the 
signal  will  go  to  the  stop  position  and  the  dynamic  indication 
current,  generated  by  the  signal  motor,  will  flow  through  the 
main  common,  indication  common,  indicator  bus,  controller 
contacts  M,  indicator  point,  binding  post  Q,  circuit  breaker  on 
signal,  to  motor.  This  will  give  no  indication  at  the  lever,  but 
will  act  as  a  snubbing  circuit  to  slow  up  the  motor  and  pre- 
vent shock  to  the  mechanism.  If  it  becomes  necessary  to 
change  the  route  after  a  signal  has  been  cleared,  the  hand 


mon,  indication  bus,  hand  switch  D,  indicator  back  point,  con- 
troller contact  K,  indication  magnet  H,  binding  post  Q,  circuit 
breaker  on  signal,  to  motor.  This  gives  the  indication  and  re- 
leases the  lever.  With  the  lever  normal  the  indication  circuit  is 
kept  closed  through  controller  contact  N  in  order  to  provide 
cross  protection  (pages  210-229).  If  for  any  reason  indica- 
tor <T  should  fail,  it  would  keep  relay  C  open  and  prevent 
the  movement  of  any  switches  in  the  route.  To  move  a  switch 
under  such  circumstances  hand  switch  D  is  reversed.  This 
closes  a  local  circuit  for  relay  C,  but  opens  the  signal  indication 
circuit.  A  switch  can  then  be  moved,  but  to  get  a  signal  in- 
dication D  must  be  restored  and  this  would  again  open  circuit 
for  C,  thus  preventing  an  improper  movement.  If  the  hand 
switch  D  should  be  operated  while  the  screw  release  is  reversed 
the  relay  C  could  not  close  because  its  return  is  cut  through 
the  lower  right  hand  contact  on  the  release. 


Fig.  2077.     Typical  Route  Locking  Circuit. 


Left  hand  side.          Right  hand  side. 


Snub  resist. 


*Vff"   umif 

n  .«•-««.  otiJo  o 


Connectors  /n  f?e/ay  box 
Ho/dc/ear  coi/s. 


I  High 


Off 


L.    (-Distant  relay  control.    r-Lock  wire.  f 


Fig.  2078.-    Circuit  for  Control  of  Power  Distant  Sig- 
nal,  Showing   Motor   Connections. 

screw  release  F  (see  Figs.  2843-2845)  must  be  first  reversed. 
This  opens  the  slot  circuit  and  restores  the  signal  to  normal : 
It  also  opens  the  circuit  for  relay  C.  These  circuits  cannot 
again  be  restored  until  the  release  is  put  normal.  Relay  C 
controls  the  circuits  for  all  the  switches  in  the  route  so  that 
when  It  is  open  no  switches  can  be  moved.  When  the  screw 
release  Is  reversed  It  breaks  the  circuit  for  indicator  G.  The 
signal  lever  m? y  then  be  restored  to  the  normal  position.  When 
Indicator  G  is  de-energized,  either  by  the  presence  of  a  train 
on  the  track  circuit  or  by  the  screw  release,  It  breaks  the  cir- 
cuit of  relay  C  and  the  snubbing  circuit  Just  described,  and 
its  back  point  closes.  This  completes  the  indication  circuit  as 
follows :  From  motor  through  main  common,  indication  corn- 


Fig.  2077  shows  an  approach  locking  circuit  which  Is  ef- 
fective only  after  signal  6  has  been  cleared  and  a  train 
has  approached  into  the  preliminary  section.  The  levers  for 
all  switches  within  the  interlocking  are  equipped  with  full 
normal  and  full  reverse  electric  locks,  Riese  locks  being  con- 
trolled through  their  respective  track  sections  and  a  front 
point  of  the  stick  relay,  which  relay  once  picked  up  will  bo 
held  up  through  its  own  front  point  until  deenergized  by  the 
clearing  of  signal  6.  When  the  stick  relay  has  been  thus  de- 
energized  the  route  'Will  be  held  locked  until  the  train,  having 
accepted  and  placed  signal  6  at  stop,  has  passed  on  to  the 
last  track  section  of  the  plant,  thereby  again  picking  up  the  stick 
relay.  If  no  train  comes,  signal  6  may  be  restored  normal  and 
the  stick  relay  will  pick  up  as  shown  in  the  circuits  through 
the  approach  and  45  deg.  control  relays  in  series.  The  stick 
relay  takes  battery  not  only  through  the  circuit  controller  on 
signal  6,  but  also  in  series  through  a  controller  (closed  45  to 
90  deg.)  on  signal  1,  which  gives  the  caution  indication  for 
signal  6  ;  this  feature  prevents  the  operator  from  taking  away 
the  route  in  case  signal  1  fails  to  return  to  the  caution  posi- 
tion after  signal  6  has  been  placed  normal.  The  stick  relay 
may  be  picked  up  regardless  of  the  relays  which  control  It,  by 
means  of  the  hand  screw  release ;  the  locks  on  the  switch  levers 
are  broken  through  this  hand  screw  release  in  its  normal  posi- 
tion, thus  forcing  the  operator  to  screw  the  hand  release  back 
to  its  normal  position  before  the  route  may  be  released. 

Fig.  2074  shows  an  approach  locking  circuit,  effective  as  soon 
as  the  home  or  the  distant  signal,  as  desired,  assumes  the 
proceed  position ;  it  also  Illustrates  the  mechanical  action  of 
the  hand  screw  release  (see  Fig.  2856).  The  home  signal  lever 
is  equipped  with  a  half  reverse  'lock  which  is  controlled  in 
series  through  the  front  points  of  the  track  and  stick  relays. 
This  stick  relay  is  held  up  through  its  own  front  point,  being 


Figs.  2079-2080 


INTERLOCKING. 


293 


de-energized  at  the  time  when  the  home  or  the  distant  signal 
Is  cleared,  as  the  case  may  be ;  the  stick  relay  will  pick  up 
again  only  when  the  signal,  through  which  Its  circuit  is  broken, 
has  gone  to  stop  and  the  train  has  entered  the  home  section. 
Therefore,  reversing  the  lever  which  controls  this  signal,  de- 
energizes  the  lock  on  the  home  signal  lever,  thus  holding  the 
route  locked  until  the  train  has  passed  completely  through  the 
interlocking.  In  case  it  is  desired  to  change  the  route  before 
the  arrival  of  the  train,  the  operator  may  screw  over  the  hand 
release  which  will  energize  the  lock  on  the  home  lever  irrespec- 
tive of  the  stick  and  track  relays.  The  screw  release  has  a  pro- 
jection which  in  the  reverse  position  butts  against  the  locking 


Fig.  2079  illustrates  a  method  of  accomplishing  check  lock- 
ing at  two  electric  interlocking  plants.  Each  plant  is  provided 
with  a  check  lock  lever.  A  is  the  master  plant,  as  its  signal 
(2)  governs  in  the  normal  direction  of  traffic,  and  under  normal 
traffic  conditions  may  be  operated  without  interference  from 
the  check  locking.  The  check  lock  levers  are  interlocked  with 
the  signal  levers.  The  check  lock  lever  at  A,  when  reversed, 
locks  lever  2  normal,  and  at  Z,  signal  lever  13,  when  reversed, 
locks  the  check  lock  lever  reversed. 

To  clear  signal  13  for  a  reverse  movement,  the  check  lock 
lever  at  A  is  first  reversed ;  this  locks  signal  2  normal.  In  re- 
versing this  lever  the  lower  contact  block  bridges  the  two 

/3 


Cfrec/rLoc/r 
Lever 


^/prrar/  Lever /?-> 


-S/gvrcr/ Lever  S 


Common 


7ow&r 
/tpproac/7 


T 


Fig.  20/9.     Check  Locking  Circuits  for  Electric  Interlocking.     General  Railway  Signal  Company. 


Push  Button  _ 
f/art ''i/tum 'Contacts.  \ 
\ 

Circuit  Controllers     ' 
>on  Signer  I  Levers^ \ 


/0-- 


-/O 


E/ecfrfc  Locks 

\-  on  Derail  Levers 

IS  Ohms  Res 


Fig.  2080.     Electric  Locking  Circuits  for  Single  Track 
Crossing.     New  York  Central  &  Hudson  River. 

bar  on  which  is  mounted  the  driving  dog  of  the  horn  >  signal  lever, 
thereby  mechanically  locking  the  tappets  of  all  functions  in  the 
route  in  the  positions  assumed.  This  insures  the  restoration  of 
the  screw  release  to  its  normal  position  before  the  route  can  be 
changed. 

Where  two  interlocking  plants  are  situated  close  together 
and  each  has  signals-  governing  toward  the  other  on  the  same 
track,  it  is  necessary  to  provide  means  to  prevent  any  two  such 
opposing  signals  from  being  cleared  at  the  same  time.  Such 
an  arrangement  of  apparatus  is  called  "check  locking." 


lower  springs  at  the  reverse  indication  stop,  closing  a  local 
circuit  through  the  indication  magnet,  and  permitting  a  full 
reversal  of  the  lever.  The  upper  contact  block  also  bridges 
the  two  upper  reverse  contact  springs,  which  closes  a  circuit 
from  the  10-volt  battery  at  A,  through  the  upper  line  wire,  the 
upper  contact  of  the  approach  indicator  at  Z  (insuring  that 
the  track  section  between  the  two  towers  is  unoccupied)  to 
the  upper  reverse  contact  spring  of  the  check  lock  lever  at  Z. 
This  lever  is  now  reversed  as  far  as  the  indication  stop.  When 
this  is  reached,  its  upper  contact  block  bridges  the  contact 
springs  at  that  point,  completing  the  circuit  just  traced,  through 
the  indication  magnet  to  common  and  back  to  its  battery  at  A. 
This  energizes  the  indication  magnet  and  permits  the  check 
lock  lever  at  Z  to  complete  its  reverse  stroke,  releasing  the 
mechanical  locking  which  has,  up  to  this  time,  held  signal 
lever  13  in  its  normal  position.  In  this  last  portion  of  the 
stroke  it  also  breaks  the  contact  just  made,  de-energizing  the 
indication  magnet. 

Trains  may  now  be  forwarded  from  Z  to  A,  their  movement 
being  governed  by  signal  13. 

To  restore  the  normal  traffic  (signal  13  having  been  put  in 
the  stop  position),  the  check  lock  lever  at  Z  is  moved  to  its 
normal  position,  locking  signal  lever  13  normal.  In  going  to 
this  position  the  lower  contact  acts  in  the  same  manner  as  with 
the  lever  at  A,  when  being  reversed.  In  the  normal  position  of 
the  lever  at  Z  its  upper  normal  contact  springs  are  bridged, 
closing  a  circuit  from  the  10-volt  battery  at  Z,  through  the 
second  contact  on  the  approach  indicator  (again  insuring  that 
the  track  is  clear  between  the  two  towers),  the  lower  line  wire, 
to  the  upper  normal  contact  spring  of  the  check  lock  lever  at 
A.  This  lever  is  now  moved  against  the  normal  indication  stop, 
completing  its  indication  circuit  in  the  same  manner  as  the 
lever  at  Z  when  reversed.  Thus  after  both  check  lock  levers 
are  restored  to  their  full  normal  position,  signal  lever  2  may 
be  reversed,  and  traffic  resumed  in  its  normal  direction. 

Fig.  2081  shows  check  locking  circuits  in  use  between  tw» 
interlocking  plants  situated  at  each  end  of  the  Bloomingburgh 
Tunnel,  on  the  New  York,  Ontario  &  Western.  This  installation 
comes  near  being  single  track  controlled  manual  blocking, 


294 


INTERLOCKING. 


Fig.  2081 


and,  in  fact,  the  same  may  be  said  of  any  effective  form  of  check 
locking. 

X  and  X',  electrically  locked  circuit  controllers  (see  Figs. 
357-357),  are  used  instead  of  check  lock  levers.  Indicators  Y, 
Y'  control  the  slot  circuits  and  are  controlled  by  X  and  X'. 
The  circuit  for  X  and  X'  is  as  follows :  Wire  B,  magnet  X', 
wire  1,  circuit  controller  on  latch  of  lever  2,  wire  1  a,  track 
relay  point,  wire  1  b,  track  relay  points  at  tower  5,  wire  1  d, 
circuit  controller  on  latch  of  lever  20,  wire  1  e,  circuit  con- 

Track  Circuit  controlling' Inter/octf/ny  Plant 

»  "       Automatic  ^Siynais. 


switch  4  is  normal  the  same  is  true  of  the  westbound  track  cir- 
cuit at  tower  6. 

After  the  passage  of  a  train  in  either  direction  it  is  not 
necessary  to  manipulate  X  and  X'  for  a  following  movement, 
but  they  must  be  changed  for  a  movement  in  the  opposite  di- 
rection. Reversal  of  either  X  or  X'  alone  has  no  effect  on  Y  or 
Y',  as  they  are  then  thrown  into  a  closed  circuit  without  bat- 
tery. 

Fig.  2082  illustrates  a  check  lock  circuit  for  installation  where 


'. On  Lever  Latcn  No,  /, 


doses  af  beg/nn/ng 


On Lever  Latch  No.  2,  changes 
af  beginning  of  stroke 


On  Lever  Latch  Mo. /8, 
chan 


On  Lever  Latch  No.ZQ, 


/nning  of  stroke.  /?-'     4a- 


'On  Lever  No.  5, 
closes  at  end  of  stroke 


On  Lever  No.  14 

On  Lever  No./.  J  ~         b 

Closes  at  En"d  | 

of  Stroke.  -=-  -=• 


X ,  X '  -  Electrically  Locked  Circuit 

Controllers. 
Y,  Y1  -  Slot  Indicators 


Common-  ^-Battery 

Fig.  2081.     Check  Locking  Circuits  and  Track  Diagram,  Bloomingburgh  Tunnel.     New  York,  Ontario  &  Western. 


troller  on  la*ch  of  lever  18,  wire  1  f,  magnet  X,  to  wire  O. 
Wires  B  and  O  are  the  two  main  battery  feeds.  It  will  be  noted 
that  reversal  of  the  knife  switch  reverses  polarity  of  feeds, 
thereby  counteracting  any  tendency  toward  residual  magnetism 
In  the  instruments. 

To  send  a  train  from  tower  5  to  tower  6  no  manipulation 
of  X  or  X'  is  necessary.  Signalman  at  6  reverses  lever  5, 
thereby  closing  circuit  controller  on  its  tappet.  Current  now 
flows  from  B  at  tower  6,  through  circuit  controller  on  lever  5, 
wire  2,  controller  X',  wire  2  a,  point  of  track  relay,  wire  2  b, 
track  relay  points  at  tower  5,  wire  2  d,  controller  X,  wire  2  e, 
magnet  of  Y,  to  O.  This  energizes  Y  and  closes  the  slot  circuit 
for  signal  18  or  20  (according  to  the  position  of  14),  when 
latch  of  either  is  raised.  Either  signal  can  now  be  cleared  for 
a  train,  but  such  action  opens  the  circuit  for  X  and  X'  and 
locks  them  in  their  normal  position.  Lever  12  must  be  re- 
versed before  18  or  20.  This  shunts  out  the  circuits,  for  X,  X' 
and  Y  from  the  points  of  eastbound  track  relay.  This  permits 
a  train  to  stand  on  the  eastbound  circuit  beyond  the  fouling 
point  of  the  crossover,  while  another  is  making  a  normal  west- 
bound movement.  The  circuit  controller  on  lever  14  selects  slot 
circuits  for  signals  18  and  20. 

To  move  a  train  from  tower  6  to  tower  5,  controllers  X  and 
X'  and  lever  1  (at  tower  5)  must  be  reversed;  also  switch  and 
derail  4  at  tower  6  must  be  reversed.  This  closes  a  circuit 
from  B  at  tower  5,  through  controller  on  latch  of  lever  1, 
wire  3,  lower  contact  of  X  (now  closed),  wire  2  d,  points  of 
track  relays,  wire  2  b,  circuit  controller  of  lever  4  (now  closed), 
wire  2  b,  circuit  controller  on  lever  4  (now  closed),  wire  2  a, 
upper  contact  of  X'  (now  closed),  wire  3  a,  magnet  of  Y',  to  O. 
This  energizes  Y'  and  closes  slot  circuit  for  signals  1  and  2 
when  their  lever  latches  are  raised.  Raising  the  latch  of  2 
breaks  the  circuit  of  X  and  X',  locking  them  reversed. 

The  presence  of  a  train  on  the  tunnel  track  circuit  opens 
both  control  circuits,  de-energizing  the  controllers  X  and  X' 
and  indicators  Y  and  Y'.  which  in  turn  opens  their  respective 
slot  circuits  automatically,  putting  the  signals  in  the  stop  posi- 
tion, holding  them  there  until  the  track  circuit  is  clear,  and 
also  locking  controllers  X  and  X'  in  whichever  position  they 
were  last  left.  When  crossover  12  is  normal  the  track  circuit  on 
the  eastbound  track  at  tower  5  has  the  same  effect,  and  when 


there  is  no  preference  as  to  direction  of  traffic.  The  check  lock 
levers  in  towers  A  and  Z  are  each  equipped  with  a  half  reverse 
lever  lock,  these  levers  being  so  interlocked  with  the  levers  for 
the  signals  governing  into  the  track  between  the  towers  that 
it  is  necessary  for  the  check  lock  lever  to  be  in  the  full  reverse 
position  before  the  signal  lever  mechanically  interlocked  there- 
with may  be  reversed.  The  operator  in  tower  A,  for  instance, 
may  reverse  his  check  lock  lever  as  far  as  the  reverse  indication 
point,  the  lever  being  held  thus  until  the  half  reverse  lock 
with  which  it  is  equipped  is  energized,  this  being  accomplished 
as  follows :  Current  will  flow  from  the  low  voltage  battery  at 
tower  Z,  through  full  normal  contacts  on  the  check  lock  lever 
iu  that  tower,  the  front  point  of  track  relay  X  (insuring  that 
the  track  section  between  the  two  towers  is  unoccupied),  the 
reverse  contacts  on  check  lock  lever  in  tower  A,  through  the 
lock  in  question  and  thence  to  common.  The  check  lock  being 
placed  in  the  full  reverse  position  releases  the  lever  for  signal  1, 
which  may  then  be  cleared  for  a  movement  from  tower  A  to  Z. 
The  check  lock  lever  in  tower  Z  cannot  be  placed  full  reverse, 
thus  allowing  signal  2  to  be  cleared,  until  the  lever  for  signal  1 
and  the  check  lock  lever  in  tower  A  have  first  been  restored 
to  the  full  normal  position.  The  operations  for  securing  the 
release  of  lever  2  are  the  same  as  those  already  described 
in  connection  with  signal  lever  1. 

Fig.  2083  illustrates  a  typical  circuit  for  the  control  of  signals 
Installed  for  tunnel  protection.  Signal  1  normally  stands  at 
the  stop  position,  being  cleared  through  a  preliminary  clearing 
section,  while  signal  2  under  normal  conditions  assumes  the 
clear  position.  The  control  relay  for  signal  1  is  broken  through 
the  track  relay  of  the  tunnel  section  and  through  the  circuit 
breaker  on  signal  2  closed  only  at  0  deg.  The  control  relay  for 
signal  2  is  likewise  governed  through  the  track  section  between 
signals  1  and  2  and  a  circuit  breaker  on  the  opposing  signal 
closed  only  at  0  deg.  ;  it  is  also  controlled  in  series  through 
the  track  relay  of  the  clearing  section.  Since  the  signals  are 
interlocked  against  each  other,  it  is  impossible  for  both  signals 
to  be  cleared  at  the  same  time,  even  through  the  improper  opera 
tion  of  one  of  the  signals.  A  train  running  from  left  to  right, 
on  entering  the  clearing  section,  will  put  signal  2  to  stop  ;  if  no 
train  is  between  signals  1  and  2,  the  control  relay  for  signal  1  will 
immediately  pick  up  and  signal  1  go  to  the  clear  position.  Signal 


Figs.  2082-2084 


INTERLOCKING. 


295 


1  will  automatically  go  to  stop  when  passed  by  the  train,  and 
until  such  time  as  the  train  will  be  clear  of  the  tunnel  section 
neither  signal  1  nor  2  can  give  a  proceed  indication.  A  move 
nient  may  then  be  made  from  the  right,  providing  another 
train  has  not  in  the  meantime  entered  the  approach  section 
for  signal  1. 


restore  his  home  signal  lever  to  the  normal  position  while  the 
train  is  in  the  home  section.  Fig.  2086  shows  a  route  locking 
circuit,  Fig.  2087  a  track  indicating  circuit  and  Fig.  2088  an 
approach  locking  circuit. 

Facing  point  locks  are  called  for  on  these  five  plans.     These 
would  be  placed  at  mechanical  plants.     If  the  circuits  are  used 


SECTION    x 


10  VOLT 
BATTERY    — 


Fig.  2082.     Check  Lock  Circuit.     General  Railway  Signal  Company. 


Confrol  relay 
for  Si' 


-M'l-l'h 


Tunr<E.i_ 


Circuit  breaker 
on 


frcuiT  breaker 
n'    on  Signal    1 


Corrrrol  ralay 
for  5ignal  1. 


Fig.  2083.     Circuit  for  Tunnel  Protection.     General  Railway  Signal   Company. 


I'ig.  2084.    Approach  and  Route  Locking  for  Slotted  or  Semi-Automatic  Stick  Signals.    Railway  Signal  Association. 


Figs.  2084-2088  show  electric  locking  circuits  for  both  me- 
chanical and  power  interlocking  plants,  presented  at  the  1911 
convention  of  the  Railway  Signal  Association.  Figs.  2084- 
2085  show  complete  electric  locking,  the  former  being  recom- 
mended for  plants  where  signals  have  semi-automatic  control ; 
and  the  latter  for  plants  not  having  such  control,  and  for  other 
places  where  it  is  thought  desirable  to  compel  the  operator  to 


at  power  plants  lever  No.  5  can  be  a  key  or  route  lever  so  ar- 
ranged as  to  lock  all  switches  in  the  route ;  or  separate  locks 
can  be  placed  on  each  switch  lever,  or  some  switch  or  derail 
lever  can  be  chosen  to  perform  the  functions  of  the  key  lever. 
At  electric  interlocking  plants  the  locks  might  be  done  away  with 
and  relays  substituted,  which  would  open  suitable  control  or  in- 
dication circuits. 


2g6 


INTERLOCKING. 


Figs.  2085-2088 


if 

t.ii  *~  * 

5                                              prrru.*    ^^^       j  !J_S 
^  14—  *— 

itJl 

1                                                                                  —    i       j. 

Jlllll— 

i 
i 

1  l__. 

TW™ 

r 
i 

N—  | 

1  

iL 

i' 

L. 

* 

M 

M 

Fig.  2085.     Approach  and  Route  Locking  Circuit. 


Fig.  2086.    Route  Locking  Circuit. 


Fig.  2087.  Track  Indicating  Circuit. 


jff 

sp 

>r 

'i  j  *[_j$j-* 

rpi.5        ^-4. 

;;:^^  a" 

t>' 

•  rr1  —  ji- 

Fi°'   2 

088     Approach  Locking  Circuil 

^  

1          !!    ^  

L_     ~"~"1 

'  I     r* 

j 

g 

Figs.  2085-2088.    Railw; 
Association  Electric 

f                   *Ji 
Ji- 

i 

S  b 

^  —        ^T 

ing   Circuits. 

f 

HIGHWAY  CROSSING  SIGNALS. 


297 


HIGHWAY  CROSSING  SIGNALS 
Pages  298-324  Figures  2089-2242 

Pages  Figures 

CROSSING  BELL  APPLICATIONS 298-303  2089-2118 

INTERLOCKING  RELAYS 303-308  2119-2145 

SIGNS  AND  BELLS 309-320  2146-2231 

TRACK  INSTRUMENT  CROSSING  SIGNAL                            320-324  2232-2242 


2g8 


HIGHWAY  CROSSING  SIGNALS. 


Figs.  2089-2091 


CROSSING  BELL  APPLICATIONS. 


The  ordinary  bell  installation  for  a  double  track  grade  cross- 
ing at  a  street  or  highway  is  shown  by  Fig.  2089.  A  bonded 
section  of  track,  1,500  ft.  to  one-half  mile  or  more,  is  used  on 
each  track  in  the  direction  from  which  trains  approach.  Insu- 
lations are  used  at  the  end  of  these  sections  as  shown  at  A,  B 
and  C.  An^lnterlocking  relay  (with  the  locking  pawl  removed) 
Is  used  to  control  the  local  bell  circuit.  Two  ordinary  relays 

Bonded  TracK 


apparatus  required  will  be  a  relay  at  the  crossing  and  two  keys 
located  so  that  they  will  be  convenient  to  trainmen  or  operators. 
The  momentary  closing  of  either  key  contact  cuts  the  belF  out 
°r  in,  It  not  being  necessary  to  retain  the  finger  on  the  key  for 
more  than  an  instant.  In  connection  with  this  feature  it 
should  be  understood  that  only  when  a  train  is  on  the  track  sec- 
tion  approaching  the  crossing  can  the  bell  be  manually  cut  out. 


—                                                           X 

** 

r~ 

2 

A!  j 

1      B 

8&xted  TracK/ 

i  ii    Two  Cells  Gravity  Battery 
PIT    connected  m  multiple  and 
\    heated  /n  C.  1.  C  forte  of  extreme 
\   :     end  of  tnacK  section 

: 

1 

ty^WeofAerproaf  BeJJ 
&    onfop  of  post 

\ 

Non-/ntcr  locking  re/oj  for^__^. 

%G 

V 

\ 

\ 

refoy  Aox 

^ 

C—imm 

^ 

ssss 

Eight  ce//.s  cc?usfic  potash  battery  in 
box  of  foof  o/be/f  post 


Fig.  2089.     Arrangement  for  Double  Track  Highway  Crossing  Bell.     The  Union  Switch  &  Signal  Company. 


would  answer  as  well,  but  it  is  sometimes  desirable  to  maintain 
the  Interlocking  type  as  a  standard  for  bell  work,  and  it  re- 
quires somewhat  less  space.  A  train  entering  the  ringing  sec- 
tions at  A  or  C  will  short  circuit  the  coils  D  or  E,  respectively, 
and  drop  an  armature.  These  armatures  carry  contact  springs 
that  close  a  local  bell  circuit  on  a  back  contact  so  that  the  bell 
G  will  ring  as  long  as  the  circuit  of  battery  F  is  closed,  that  is, 
until  the  armatures  of  both  L>  and  K  are  "picked  up,"  which 
occurs  when  the  train  passes  out  of  the  sections  A  to  B  or  C  to 
B.  The  notations  on  the  cut  are  self-explanatory. 


It  may  again  be  cut  in,  when  it  will  ring  until  the  train  passes 
over  the  highway  ;  or  should  the  operator  neglect  to  cut  the  bell 
in,  the  train  will  automatically  perform  this  operation  in  pass- 
ing out  of  the  bonded  sections,  and  restore  the  instruments  to 
their  normal  positions  so  that  the  bell  will  again  ring  for  the 
next  approaching  train.  The  following  examples  will  Illustrate 
a  few  of  the  conditions  met  in  actual  practice  and  will  give  an 
idea  of  the  many  instances  where  a  highway  crossing  bell  can  be 
used  successfully  and  to  advantage  at  points  where  the  track 
layout  or  switching  conditions  are  somewhat  complicated  : 


Fig.   2090.     Arrangement   for   Single  Track   Highway   Crossing  Bell.     The  Union  Switch  &  Signal  Company. 


A  single  track  crossing  bell  layout  is  shown  in  Fig.  2090.  As 
stated  in  the  description  of  Fig.  2089,  the  track  is  bonded  for 
1,500  ft.  to  one-half  mile  or  more  on  each  side  of  the  crossing 
from  A  to  B  and  C  to  B.  As  a  train  enters  from  either  end, 
the  interlocking  relay  makes  back  contact  on  one  or  the  other 
of  the  contact  fingers  attached  to  the  armatures  D  and  E, 
which  completes  the  local  bell  circuit  of  battery  F.  As  it  is 
desired  to  stop  the  bell  as  soon  as  a  train  has  passed  over  the 
crossing,  after  entering  the  ringing  section,  a  means  must  be 


Cas\J,)  If  an  approaching  train  enters  the  bonded  section  at 
A  and  stops  at  Station  F  the  bell  E  at  the  highway  would  or- 
dinarily ring  during  the  time  that  stop  is  made  and  until  the 
train  again  proceeds  and  passes  beyond  Jhe  crossing.  In  con- 
sequence, the  bell  is  ringing  during  the  time  that  train  is  at  a 
stop,  and  the  street  is  open  to  the  safe  passage  of  the  public. 
If  such  a  condition  is  allowed  to  continue,  the  bell  ceases  to  be- 
come a  warning  and  is  locally  classed  as  a  public  nuisance.  A 
stop  and  start  key  is  installed  in  the  station.  Under  these  con- 


fl 


Fig-.  2091.     Special  Crossing  Bell  Layout 


provided  to  prevent  the  armature  of  that  part  of  the  relay  con- 
trolled from  the  section  beyond. the  crossing  from  dropping  far 
enough  to  make  back  contact  when  a  train  passes  the  crossing. 
The  locking  pawl  H  is  provided  for  this  purpose,  as  is  explained 
in  connection  with  Figs.  2119-2123.  Thus,  the  bell  will  ring 
from  the  time  a  train  enters  the  section  until  it  passes  over  the 
crossing. 

Fig.  2091  will  serve  to  illustrate  a  number  of  special  condi- 
tions under  which  it  is  advisable  to  use  special  keys  in  addition 
to  the  standard  layout,  in  order  to  stop  and  start  a  crossing 
bell  In  connection  with  certain  train  movements  as  a  means  of 
preventing  false  alarms  and  continuous  ringing!  The  additional" 


ditions  the  agent  presses  the  stop  key  when  the  train  slows  down 
and  the  bell  consequently  ceases  to  ring.  If  the  crossing  is  very 
close  to  the  station  no  starting  key  is  required,  for  the  train  may 
proceed  slowly  over  the  crossing  with  the  engine  bell  ringing, 
and  in  passing  beyond  the  bonded  sections  will  automatically 
restore  the  instruments,  as  before  stated.  Should  the  crossing 
be  some  distance  from  the  station,  however,  the  agent  may  press 
a  starting  key  when  the  train  is  ready  to  proceed,  and  give  the 
proper  warning  at  the  highway.  In  this  latter  instance  of 
course  the  bell  will  stop  ringing  when  the  entire  train  has  passed 
over  the  crossing. 

Case    2.      Referring    to    the   same   layout,   should    F   be   a   day 


Figs.  2092-2097 


HIGHWAY  CROSSING  SIGNALS. 


299 


station  only,  or  for  any  reason  should  It  be  undesirable  for  the 
agent  to  handle  operating  keys,  the  same  results  may  be  ob- 
tained as  outlined  in  Case  1,  by  inserting  short  one-rail  sections 
in  the  track  circuit  approaching  the  crossing  in  lieu  of  the  keys, 
and  thereby  make  the  cut-in  and  cut-out  feature  dependent  en- 
tirely on  the  location  of  the  engine  relative  to  the  crossing ;  or  a 
train  in  coming  to  a  stop  at  the  station  passes  onto  a  stop  sec- 
tion and  automatically  cuts  the  bell  out  of  circuit.  When  the 
same  train  again  proceeds  the  engine  enters  a  starting  section 
located  at  a  specified  distance  from  the  crossing  and  bell  again 
rings,  it  being  understood  that  the  stop  and  start  sections  are 
such  a  short  distance  apart  that  a  through  train  approaching 
the  crossing  at  speed  will  give  practically  a  continuous  warn- 


Fig.     2092. 


Re/qy  not 
Interlocked. 


Crossing     Bell     Circuits,     Double     Track. 
Railroad  Supply  Company. 


Fig.  2094.     Crossing  Bell  Circuits,  Two  Single  Tracks. 
Railroad  Supply  Company. 


1*1 


Fig.  2096.     Crossing  Bell  Circuits,  Single  Track,  Auto- 
matic Starting  Section,  with  "Cut-out"  and  "Cut-in" 
Keys.     Railroad  Supply  Company. 


D  will  give  a  false  alarm  at  the  crossing  during  the  time  that 
section  CD  is  occupied.  This  situation  can  be  properly  protected 
so  that  bell  wijl  not  ring  for  a  train  entering  CD  from  the  sld- 
J9gi_Rr<?vided  the  train  proceeds  in  a  direction  away  from  the 
crossing.  Should,  however,  a  train  clear  the  switch  and  run 
toward  the  highway  a  sufficient  warning  will  be  given. 

Figs.  2095-2096  illustrate  circuits  used  to  cover  some  of  the 
conditions  mentioned  above. 

Fig.  2092  shows  the  circuits  for  a  double  track  crossing  bell, 
using  the  relay  shown  in  Fig.  2128,  but  with  fingers  so  arranged 
as  not  to  interlock.  A  train  in  either  section  shunts  the  relay 
magnet,  allowing  its  finger  to  make  contact  with  back  point, 
thereby  establishing  a  circuit  through  the  bell. 


Fig.     2093.     Crossing     Bell     Circuits,     Single     Track. 
Railroad  Supply  Company. 


Fig.  200^.     Crossing  Bell   Circuits,   Single  Track,  with 
'Tut-out"  and  "Cut-in"  Keys.     Railroad  Sup- 
ply Company. 


One  or  firo  raif /ent?ffrs_ 


ft 


Fig.  2097.     Single  Track  Crossing  Bell  Circuits,  With- 
out Interlocking  Relay.     Delaware,   Lackawanna 
&  Western. 


ing,  as  its  effect  in  passing  over  the  cut-out  and  cut-in  section 
will  cause  no  noticeable  interruption  to  the  bell  circuit. 

Case  3.  Should  the  approach  section  to  a  bell  include  a 
switch  as  shown  at  C  (Fig.  2091),  it  is  advisable  to  provide  a 
stop  and  a  start  key  at  such  a  switching  point  for  the  con- 
venience of  train  men  in  controlling  the  ringing  of  the  bell  while 
switch  is  being  used  and  cars  are  being  switched  on  and  off  the 
bonded  section.  The  keys,  are  usually  placed  in  a  shelter  and 
mouat£d_upon  a  post  adjacent  to  the  switchstand.  Keys  at  C 
and  F,  or  at  a  number  of  different  points,  may  be  used  to  control 
the  same  bell  without  in  any  way  conflicting  with  its  operation. 

Case  4.  Should  C  (Fig.  2091)  be  a  switch  leading  to  a  passing 
siding  or  at  the  end  of  a  double  track,  it  may  be  readily  seen 
that  a  train  coming  on  to  mnin  line  at  C  and  proceeding  toward 


Fig.  2093  shows  the  circuits  for  a  single  track  crossing  bel;. 
using  the  relay  shown  in  Fig.  2128.  A  train  in  either  section 
affects  the  relay  as  in  Fig.  2092,  but  when  it  passes  from  ono 
section  to  the  other,  the  magnet  of  the  first  section  picks  up, 
raising  both  metal  strips  and  thereby  stopping  bell. 

Fig.  2094  shows  two  single  track  installations  operating  one 
bell  in  common.  The  circuit  arrangement  is  an  adaptation  of 
Fig.  2093. 

Fig.  2095  shows  a  device  for  stopping  the  bell  while  a  train  is 
in  the  initial  section  and  for  starting  it  again  if  so  desired. 
The  relays  are  similar  to  the  one  shown  in  Fig.  2128.  A  train  in 
either  section  <lp-onprH^ps  nnp  or  the  other  of  theinagneta^of 


lay. 


300 


HIGHWAY  CROSSING  SIGNALS. 


Figs.  2098-2100 


bell,  back  point  of  upper  relay,  finger,  back  right-hand  point  and 
finger  of  lower  relay,  back  to  battery.  The  lower  relay  is  nor- 
mally de-energized  and  is  not  interlocked.  If  desired  to  stop 
the  bell,  the  upper  key  is  pressed  down.  This  completes  a  circuit 
from  battery,  through  key,  left-hand  magnet  of  .lower  relay,  back 
point  and  finger  of  upper  relay,  back  point  and  finger  of  right- 
hand  magnet  of  lower  relay  to  battery.  This  energizes  the  left- 
hand  magnet  of  the  lower  relay  which  picks  UP  its  armature  and 
breaks  the  bell  circuit.  At  the  same  time  it  e"sTablishes  a 
"stick"  circuit  through  its  front  point,  thereby  keeping  itself 
energized  while  the  train  remains  in  the  section.  To  start  bell 
again,  the  lower  key  is  pressed  which  energizes  right-hand 


section  proper,  thereby  assuring  continuous  ringing  under  nor- 
mal operation.  This  arrangement  is  used  where  trains  make  a 
station  stop  on  a  crossing  bell  track  circuit. 

Fig.  2097  shows  how  a  single  track  crossing  bell  may  be 
operated  without  an  interlocking  relay.  Suppose  a  train  enters 
the  section  at  battery  A'.  Relay  A  will  be  de-energized  and 
cause  the  bell  to  ring  through  a  circuit  from  battery  D,  through 
bell,  middle  back  contact  of  relay  A,  back  contact  of  relay  B,  to 
battery.  When  the  train  enters  the  short  middle  section,  relay 
B  picks  up  and  opens  the  bell  circuit!  Relay  A  also  picks  up 
when  train  has  left  its  section.  Relay  B  is  a  "stick"  relay  and, 
when  energized,  closes  its  own  circuit  from  battery  B'  through 


Fig.  2098.     Normally  Closed  Line  Circuits  for  Double  Track  Crossing  Bell,  with  Track  Instruments. 


Fig.  2099.     Normally  Open  Line  Circuits  for  Single  Track  Crossing  Bell,  with  Track  Instruments. 

\ 


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Fig.  2100.     Normally  Closed  Line  Circuits  for  Single  Track  Crossing  Bell,  with  Track  Instruments. 


magnet  of  the  lower  relay  opening  the  "stick"  circuit  and  de- 
energizing  the  left-hand  coil.  Releasing  the  lower  key  restores 
the  lower  relay  to  its  normal  condition,  and  the  bell  rings  until 
the  train  has  passed  out  of  the  section,  as  in  Fig.  2093.  The 
"stick"  circuit  Is  broken  in  any  event  when  the  train  leaves 
the  section.  This  arrangement  is  used  where  much  switching 
is  to  be  done  on  the  track  circuit. 

Fig.  2096  shows  a  circuit  to  accomplish  the  same  results  as 
Fig.  2095,  except  that  the  bell  starts  automatically  when  train 
reaches  the  short  independent  track  circuit.  The  "stick"  relay  is 
energized  by  pressing  the  lower  key,  and  de-energized  by  pressing 
the  upper  key,  or  by  the  opening  of  the  track  relay  in  the  short 
section.  This  relay  also  breaks  the  circuit  for  the  bell  track 


front  point  and  coil  of  relay  B,  back  to  battery  B',  when  either 
A  or  C  is  de-energized.  When  the  train  enters  the  section  C, 
the  bell  does  not  ring  as  its  circuit  remains  broken  by  relay  B. 
When  the  train  passes  battery  C',  relay  C  picks  up  and  shunts 
relay  B  by  a  short  circuit  from  battery  B',  through  front  point 
of  relay  B,  front  points  of  relays  A  and  C  to  battery  B'. 
This  de-energizes  relay  B  and  restores  the  apparatus  to  its 
normal  condition.  Suppose  while  the  first  train  was  in  track 
circuit  C  a  second  train  should  enter  track  circuit  A.  Relays 
A  and  C  would  both  be  de-energized  and  relay  B  energized. 
The  bell  would  ring  for  the  .second  train  by  a  circuit  from 
battery  D,  through  the  lower  bell,  lower  back  contact  of 
relay  C,  lower  back  contact  of  relav  A,  back  to  battery  D. 


Figs.  2101-2108 


HIGHWAY  CROSSING  SIGNALS. 


301 


Fig.  209 S  shows  double  track  crossing  bell  circuits  using  track 
instruments  or  "trips."  A  train  passing  over  either  Instrument 
marked  "start"  will  open  the  circuit  of  the  500-ohm  relay  with 
which  it  is  connected,  de-energizing  the  relay  and  closing  the 
bell  circuit.  The  relay  breaks  its  own  circuit  and  the  bell  con- 
tinues to  ring  until  instrument  marked  "stop"  is  depressed,  when 
the  relay  is  again  energized  and  completes  the  original  "stick" 
circuit  through  its  own  armature  and  the  starting  instrument- 


ergizes  the  right-hand  relay  which  breaks  the  circuit  for  the 
first  relay,  stopping  the  beli,__and  closes  its  own  circuit  through 
a  front  point.  Now  depressing  either  starting  instrument  has 
no  effect,  but  depressing  cither  "stop  release"  Instrument  shunts 
the  right-hand  relay  and  restores  the  apparatus  to  normal. 
~ng.  ziuo  snows  single  track  crossing  bell  circuits  using  track 
instruments,  with  control  relays  normally  energized.  Depres- 
sion of  either  starting  instrument  breaks  "stick"  circuit  of  mid- 


f 


g.  2101.    Bell  Starts  as  Train  Approaches  and 
Stops  as  the  Last  Car  Passes. 


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Fig.  2102.    Both  Bells  Start  Ringing  at  the  Same  Time 
and  Each  Stops  as  the  Last  Car  Passes. 


Fig.  2103.     Bell  Starts  as  Trains  Approach  on 

Either  Track  and  Stops  as  the  Last 

Car  Passes. 


Fig.  2104.     Both  Bells  Start  Ringing  at  the  Same  Time 
and  Each  Stops  as  the  Last  Car  Passes. 


IXL 


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Fig.  2105.    Bell  Starts  as  Train  Approaches  and 
Stops   as   the   Engine   Passes. 


5 


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<y 


Fig.  2106.    Bells  Start  at  the  Same  Time  and  Each  Stops 

at  the  Last  Car.     Interlocking  Features  of 

Both  Relays  Removed. 


Fig.  2107.    Bell  Starts  as  Train  Approaches  and  is  Stopped 

by  Push  Button.    Last  Car  Restores  the 

Circuit  to  Normal. 


Fig.  2108.    All  Bells  Start  at  the  Same  Time  and  Each 
Stops  as  the  Last  Car  Passes. 

Figs.  2101-2108.    Diagrams  of  Crossing  Bell  Circuits.    Bryant  Zinc  Company. 


Fig.  2099  shows  single  track  crossing  bell  circuits  using  track 
instruments  with  relays  normally  de-energized.  The  depression 
of  a  starting  instrument,  energizes  left-hand  relay,  which  closes 
its  own  circuit  through  one  front  point  and  the  bell  circuit 
through  the  other.  The  "stick"  circuit  holds  until  the  train 
reaches  the  crossing.  Depressing  the  stopping  instrument  en- 


die  relay,  which  rings  the  bell  through  Its  back  contact.  De- 
pressing the  "stop"  instrument  picks  up  the  left-hand  relay. 
This  relay  "sticks"  through  one  front  point  and  closes  the  cir- 
cuit for  middle  relay  through  the  other  two.  Depressing  either 
"stop  release"  breaks  the  circuit  of  right-hand  relay,  which  opens 
the  circuit  of  left-hand  relay,  restoring  the  apparatus  to  normal. 


302 


HIGHWAY  CROSSING  SIGNALS. 


Figs.  2109-2116 


_L 


V 


Fig.  2109.  (Train  Moving  from  Siding  to  Main  Track 
Continuing  West  Will  Not  Cause  Bell  to  Ring.  If 
Train  Goes  East  After  Reaching  Main  Track,  Bell 
Will  Start  to  Ring  When  First  Trucks  Pass  B. 
Through  Eastbound  Trains  Start  Bell  at  A.  Bell  Stops 
Ringing  as  it  is  Passed  by  the  Last  Car).  Bryant 
Zinc  Company. 


¥ 


Fig.  21 10.     Single  Track  Circuit  with  Automatic  Time 

Control    Cut-out.      Bell   Rings    for   Predetermined 

Time  if  Train  Stops  Within  Limits. 


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Fig.    21  1  1.     Bell    Starts   Ringing   as    Trains   Approach 

Crossing     on    Either   Track   and    Stops    Ring- 

ing  as  it  is  Passed  by  the  Last  Car.    Bryant 

Zinc   Company. 


Fig.  2112.     False  Alarm  Circuit  for  One  Bell  on  Single 

Track  Using  Switch  Box  Operated  by  Siding 

Switch.     (See  Fig.  2109.)     Bryant  Zinc 

Company. 


Figs.  2113-2114.  Standard  Single  Track  Circuit,  with  Entirely  Automa- 
tic Cut-in  Section.  (Used  at  Places  Where  Trains  Stand  on  Tracks 
Some  Distance  from  Highway.  Its  Bell  Has  Been  Silenced  by  Strap 
Key  L.  Trains  Approaching  Crossing  Will  Automatically  Start  Bell 
Upon  Reaching  "R"  and  Bell  Will  then  Ring  until  Rear  Trucks  Have 
Passed  Highway.)  Railroad  Supply  Company. 


Figs.  2115-2116.     Standard  Circuit  for  Bell  System  at  Outlying  Districts. 


Figs.  2117-2123 


HIGHWAY  CROSSING  SIGNALS. 


303 


TIME   C  ~CUIT   BREAKER 


Figs.  2117-2118.     Standard  Circuit  for  Single  Track  Without  Track  Circuits.     Bell   Begins  to  Ring  at  Outlying 
Track  Instruments  and  Is  Silenced  When  Train    Reaches    Highway.      Railroad    Supply    Company. 


INTERLOCKING  RELAYS 


UNION  INTERLOCKING  RELAY. 

Figs.  2119-2123  illustrate  the  method  of  interlocking  em- 
ployed in  the  Union.  Switch  &  Signal  Co.'s  relays.  To  apply  this 
to  the  enclosed  relay  shown  in  Fig.  2143  it  is  necessary  to 
consider  the  pawl  inverted  and  the  armatures  hinged  on  the 
opposite  sides  at  the  pole  pieces. 

Fig.  2119  illustrates  the  normal  condition  of  the  relay  with 
both  coils  energized  and  both  armatures  picked  up.  In  this 
position  of  the  relay  the  swinging  pawl  F  is  held  as  shown 
by  the  weight  at  its  lower  end. 

In  Fig.  2120  a  train  has  entered  the  section  at  A  and  the 
arm  H  has™ dropped  on  account  of  the  de-energizing  of  relay 
magnet  K.  When  the  arm  H  dropped  it  tilted  the  pawl  F 
slightly  to  the  left  and  at  the  same  time  the  mntnct  finp°-  in- 


the circuit  through  the  back  contact  M   causing  the  bell 


track  circuit  section.  Magnet  K  has  picked  up  its  armature 
and  the  contact  finger  E  no  longer  closes  the  bell  circuit 
through  M,  so  that  the  bell  is  not  ringing.  But  magnet  L 
Is  still  de-energized  on  account  of  the  presence  of  the  train  to 
the  right  of  the  insulated  joints  B,  and  the  arm  I  is  held  by 
the  notch  in  the  pawl  F  so  that  the  contact  finger  G  still  does 
not  close  the  bell  circuit  at  N.  Thus  'Whichever  armature  drops 
first  causes  the  bell  to  ring  while  the  train  is  in  the  correspond- 
ing side  of  the  track  circuit  but  at  the  same  time  prevents  the 
other  armature  from  closing  the  bell  circuit  even  though  the 
magnet  governing  this  other  armature  is  de-energized. 


to  ring. 


INTERLOCKING  RELAYS. 

Fig.     2124    shows    an    interlocking    relay 
track  relays  mounted  on  the  same  base. 


consisting    of    two 
Each  armature  carries 


]TRAIN|>  A 


_TRAIN  > 


£*M"    N 

FiV    2Tgn— 


M  N 

Fig.  2122.  Fig.  2123. 

Figs.  2119-2123.     Showing  Operation  of  Locking  Pawl     in  Interlocking  Relay. 


Fig.  2121  shows  the  condition  of  the  apparatus  when  the 
train  is  spanning  the  insulation  between  the  two  sections  and 
is  short-circuiting  the  relays  in  both.  In  the  figure  both 
magnets  are  de-energized,  but  on  account  of  the  position  of  the 
pawl  F  the  arm  I  drops  into  the  notch  of  the  pawl.  Its  move- 
ment to  this  position  is  not  enough  to  carry  the  contact  finger 
G  to  the  back  contact  N,  so  that  G  is  thus  prevented  from 
closing  the  bell-ringing  circuit  at  N. 

Fig.  2122  shows  the  apparatus  after  the  train  has  passed  the 
dividing  line  between  the  two  sections  and  is  in  the  second 


a  projection  to  which  is  fastened  a  lug  carrying  a  roller.  Two 
pawls,  G  and  H,  are  suspended  between  the  projections.  These 
pawls  are  pivoted  and  so  counterweighted  as  to  stand  nor- 
mally with  their  straight  sides  vertical.  In  the  figure  the  left- 
hand  armature,  B,  is  shown  released.  In  this  position  Its 
roller  bears  against  pawl  G,  forcing  its  upper  extremity  under 
projection  on  armature  E.  If  the  magnet  D  should  be  de- 
energized,  E  cannot  drop  because  it  will  rest  on  G,  and  If  A 
is  then  energized,  raising  B,  E  will  still  be  held  up  by  the 
pawl  G,  because  the  friction  between  the  projection  and  the 


304 


HIGHWAY  CROSSING  SIGNALS. 


Figs.  2124-2127 


dog  Is  sufficient  to  overcome  the  effect  of  the  counterweight. 
When  D  is  again  energized,  the  weight  of  B  is  removed  from 
Gf  which  at  once  assumes  its  normal  position.  Pawl  H  acts 
In  like  manner  on  armature  B.'  Each  armature  is  fitted  with 
four  front  and  four  back  contacts. 


The  interlocking  relay  shown  in  Fig.  2127  corsists  essentially 
of  two  ordinary  track  relays,  mounted  side  by  side  on  the  same 
base.  To  each  armature  is  fastened  a  locking  arm,  which  moves 
up  or  down  as  the  magnets  are  energized  or  de-energized.  Near 
the  outer  end  of  these  arms  and  operated  by  their  movement  are 


Fig.  2124.     Enclosed  Interlocking  Relay. 


Fig.  2125.    Enclosed  Interlocking  Relay. 


Fig.    2126.     Bottom    View    of    Hall    Interlocking    Relay. 
Hall  Signal  Company. 

The  relay  shown  In  Fig.  2125  accomplishes  the  same  results 
as  those  already  described,  but  in  a  different  manner.  The 
two  arms  extend  diagonally  from  the  armatures,  and,  meeting 
In  the  center,  are  so  arranged  to  interlock  with  each  other 
that  when  one  armature  rings  the  bell  the  other  Is  not  permitted 
to  do  so,  until  both  are  restored  to  their  normal  position. 
This  relay  is  fitted  with  three  front  and  three  back  contacts 
In  addition  to  the  one  that  rings  the  bell. 


Fig.  2127.     Interlocking  Relay.     Hall  Signal  Company. 

suspended  two  locking  dogs,  one  for  each  arm.  These  dogs  are 
pivoted  and  counterweighted  in  such  a  manner  that  when  both 
locking  arms  are  raised  both  dogs  are  released  and  swing  out- 
ward by  gravity.  If  while  In  this  ^ositlon  either  armature 
should  drop,  for  instance  armature  No.  1,  the  locking  arm  of 
that  armature  would  strike  projecting  portion  of  opposing 
locking  dog,  causing  dog  to  swing  back  under  the  locking  arm 
of  armature  No.  2  far  enough  to  interfere  with  its  dropping 


Figs.  2128-2130 


HIGHWAY  CROSSING  SIGNALS. 


305 


Fig.  2128.     Interlocking  Relay,  Normally  Energized.    Railroad  Supply  Company. 


sufficiently  to  make  a  back  contact.  Before  armature  No.  2  can 
make  a  full  drop  both  armatures  must  be  lifted  to  their  nor- 
mal position,  when  the  dropping  of  either  one  will  prevent  the 


BRYANT    ZINC    INTERLOCKING    RELAY. 

Fig.    2139   shows  a   relay   of  standard  construction   with   the 
exception   of    the    interlocking   feature,    which    consists    of   two 


other  from  making  a  full  drop  until  both  are  again  raised  to       small,  flat,  brass  hooks,  which  are  suspended  so  that  they  are. 
their  normal  position.  overbalanced    and    stand    normally    in    one    position.      To    each 


Fig.  2129.   Style  "HH"  Interlocking 
Relay   with    One   Interlocking 
Contact.     Railroad  Sup- 
ply Company. 


Fig.  2130.  Style  "HH"  Interlocking 

Relay   with    One    Interlocking 

Contact  and  Four  Front  and 

Four  Back  Contacts. 


306 


INTERLOCKING. 


Figs.  2132-2138 


Fig.  2132.     Style  "E"  Interlocking  Relay.    Railroad  Supply  Company. 


Fig.  2133.     Normal  Condition.     No  Trains  on  Either 
Track  Circuit.     Bell   Not   Ringing. 


Fig.    2134.     Train    on    Left    Track    Circuit.      One    Arma- 
ture Released,  with  Platinum  Against  Platinum 
Back  Contact.     Bell  Ringing. 


~.  ~     .  ~  TJ   .1       T      1       Fig     2n6.     Tram    Past    Crossing    and    Occupying    Right 

Fig.    2135.     Train    at    Crossing    Occupying    Both     Track  f*     * 

Track   Circuit.     One  Armature   Normal.     Other 


Circuits.     Both  Armatures  Released. 
Ringing. 


Bell 


Armature   Resting  Ivory  Point  Against 
Back  Contact.     Bell   Stopped. 


Figs.  2133-2136.     Operation  of  Contact  Fingers.     Style  "E"    Relay.     Railroad  Supply  Company. 


Figs.    2137-2138.     Armature    and    Contact    Arrangements.     Style  "W  W"  Relay.     Railroad  Supply  Company. 


Figs.  2139-2143. 


HIGHWAY  CROSSING  SIGNALS. 


307 


Fig.  2139.     Interlocking  Relay.     Bryant  Zinc  Company. 


- 


armature  is  rigidly  attached  an  aluml 
num  arm,  which  engages  the  hook  at  the 
other  end  of  the  frame  of  the  relay. 
None  of  the  interlocking  parts  are  used 
as  a  part  of  the  circuit. 

Under  normal  conditions,  with  both 
sets  of  coils  energized,  the  two  aluminum 
arms  are  held  out  of  the  way  of  the  brass 
hooks.  •  The  dropping  of  either  armature 
will  raise  the  aluminum  arm  until  it  en- 
gages the  hook,  which  will  be  moved  to 
such  a  position  that  it  is  directly  under 
the  armature  which  is  still  energized.  If 
at  this  time  the  second  set  of  coils  is 
de-energized  its  armature  will  drop  and 
rest  on  the  brass  hooks,  which  hold  it 
in  such  a  position  that  the  back  contact 
is  not  made.  If  the  first  set  of  colls  is 
again  energized,  its  armature  will  be  at- 
tracted ;  the  aluminum  arm  will  be 
moved  downward  away  from  the  hook, 
which  is  now  held  in  place  by  the  arma- 
ture of  the  second  set  of  colls,  which 
coils  are  still  de-energized. 

Current  now  being  applied  to  the  sec- 
ond set  of  coils,  will  raise  its  armature, 
thus  allowing  the  hook  to  resume  Its 
normal  position. 

The  standard  resistance  is  four  ohms. 


Fig.  2140.     Interlocking  Relay.     Normally  De-energized. 
Railroad  Supply  Company. 


Mason    Interlocking   Relay. 


Railroad    Supply   Company 


Fig.  2142.     One- Way  Ivory  Con- 
tact   Points,    Railroad    Sup- 
ply   Company. 


Fig.  2143.     Open  Type  Interlocking  Relay. 
Apparatus  Company. 


United  Electric 


308 


HIGHWAY  CROSSING  SIGNALS. 


Figs.  2144-2145 


Fig.  2144.     Enclosed  Universal  Interlocking  Relay. 


UNION    UNIVERSAL    INTERLOCKING    RELAY. 

Fig.  2144  shows  the  enclosed  "Universal"  interlocking  relay 
made  by  the  Union  Switch  &  Signal  Co.  It  consists  essentially 
of  two  ordinary  relays  mounted  on  one  base.  In  this  instru- 
ment, however,  the  contact  points  project  beyond  the  hinged 


side  of  the  armature.  Thus  the  back  contacts  are  above  and  the 
front  contacts  below.  The  interlocking  device  consists  of  two 
arms,  one  projecting  from  each  armature,  which  strike  against 
a  pivoted  pawl.  All  movable  parts  are  enclosed  in  a  dust- 
proof  case,  forming  the  base  of  the  relay. 


Fig.  2145.     Enclosed  Type  Interlocking  Relay.     United  Electric  Apparatus  Company. 


Figs.  2146-2150 


HIGHWAY  CROSSING  SIGNALS. 


309 


SIGNS  AND  BELLS. 


Fig.  2146.    Crossing  Signal  Com- 
plete,   with    Double    Gong    En- 
closed Bell,  and  Sign.    Ameri- 
can    Railway     Signal      Com- 
pany. 


Fig.  2147.  Crossing  Bell,  Re- 
lay Box  and  Battery  Case, 
with  Iron  Pipe  Post  and 
Crossing  Sign.  The  Union 
Switch  &  Signal  Company. 


Fig.    2148.      Crossing    Bell    and 
Relay  Box  on  Iron  Post,  with 
Crossing   Sign.      Bryant    Zinc 
Company. 


Figs.  2149-2150.     Signs  and  Bells.     (These  can  be  Mounted  on  any  Post.)     Bryant  Zinc   Company. 


3io 


HIGHWAY  CROSSING  SIGNALS. 


Figs.  2151-2155 


c 


Fig.  2151.  Crossing  Bell  and 
Relay  Box  on  Iron  Post,  with 
Sign.  Bryant  Zinc  Company. 


Fig.  2152.     Bell  and  Relay  Box 

on    Iron    Post,    with    Sign. 

Bryant   Zinc   Company. 


Fig.  2153.     Bell  and  Relay  Box 

on    Iron    Post,    with    Sign. 

Bryant   Zinc   Company. 


ILLUMINATED    HIGHWAY    CROSSING    SIGNALS. 

Figs.  2160  and  2161  show  two  types  of  illuminated  highway 
crossing  alarm  signals  which  are  manufactured  by  the  Bryant 
/inc  Co. 

The  sign  shown  in  Fig.  2161  consists  of  an  iron  box  In  the 
sides  of  which  is  cast  the  word  "danger"  in  seven-inch  letters. 
A  special  heavy-wired,  ribbed  plate  glass  is  used  for  the  dis- 
play of  the  sign. 

This  sign  is  made  in  two  parts,  which  are  bolted  to  the 
pole.  Each  side  is  lighted  by  a  six-volt,  two-candle-power 
tungsten  lamp.  The  current  consumption  of  these  lamps  Is 
420  milli-amperes  each,  or  840  milli-amperes  for  the  sign. 
The  length  over  all  is  35  inches.  The  letters  can  be  made 
to  show  in  either  red  or  white. 

The  energy  for  operating  the  lights  is  supplied  by  the  bell 
battery,  the  lights  being  connected  up  in  multiple  with  the  bell 
mechanism. 

Fig.  2160  illustrates  another  method  of  illuminating  a  high- 
way crossing  sign.  Two  heavy  case  reflector  hoods  are  sup- 
ported over  the  sign  in  such  position  that  a  clear  white  light 
is  thrown  on  the  letters  of  the  sign,  making  it  readable  at 
night.  The  hoods  are  fastened  to  a  steel  pipe,  which  screws 
into  an  iron  collar,  which  fits  over  the  top  of  the  pole.  The 
reflector  is  protected  by  heavy  wired  glass  and  the  entire 

2154.  Method  of  Attach-  Fig.  215;.  Bell  Si°-n  hood  is  weatherproof.  Each  reflector  contains  a  six-volt  two- 
r>^n  T)  candle-power  tungsten  lamp.  This  illuminated  signal  has  the 

to  Battery  and  Relay  Box.  Rail-  same  current  consumption  as  the-  signal  in  Fig.  2161,  viz.,  420 
Lnutes.  Bryant  Zinc  Com-  road 


pany. 


Supply 
pany. 


Com-    milli-amperes    per    bell,    or    a    total    of    820   milli-amperes.    The 
lights  are  in  multiple  with  the  bell  as  in  Fig.  2161. 


Figs.  2156-2163 


INTERLOCKING. 


Fig.  2156.  Fig.  2157.  Fig.  2158.  Fig.  2159. 

"igs.    2156-2159.       Locomotive  Type  Highway  Crossing    Bells    Showing  Various  Forms  of    Signs,    and     Attach- 
ments.    Railroad  Supply  Company. 


2160-2161.       Illuminated     Highway   Crossing 
Signals.    Bryant    Zinc    Company. 


Figs.    2162-2163.      Bells,    Posts  and  Signs.   Railroad 
Supply  Company. 


312 


HIGHWAY  CROSSING  SIGNALS. 


Figs.  2164-2167 


Fig.  2164.     Illuminated   Highway   Crossing   Signal.     C.   F.    Massey   Company. 


Fig.  2165.     Illuminated   Highway  Crossing  Signal.     C.   F.    Massey   Company. 


MASSEY    ILLUMINATED    CROSSING    SIGNAL. 

This  signal  consists  of  a  re-inforced  concrete  pole  with  relay 
box  and  bronze  disk  danger  sign.  Conduit  leads  are  embedded 
in  the  center  of  the  pole  from  the  base  to  the  relay  box  and 
from  the  box  to  the  lamp.  The  lamp  is  fastened  between  the 
bronze  discs  so  that  when  there  is  a  train  at  the  crossing  a 
red  light  is  displayed  behind  words  indicating  danger.  The 
batteries  are  housed  in  the  battery  well  at  the  base  of  the  pole. 
The  height  of  the  pole  above  the  rail  is  16  ft.,  and  the  disc  is 
2  ft.  6  in.  in  diameter.  The  light  is  in  multiple  with  the  bell  and 


is  thus  operated  from  the  same  batteries.  Figs.  2164  and  2165 
are  views  of  the  illuminated  crossing  signal  in  service ;  and  Pigs. 
2166  and  2167  show  the  signals  with  a  different  equipment  of 
bell  and  sign.  In  the  latter  figures  the  Railroad  Supply  Co.'s 
locomotive  type  bell  is  made  use  of.  The  crossing  signals  are 
made  of  reinforced  cement,  both  the  relay  boxes  and  the  circular 
head  -which  carries  the  illuminated  disk  being  reinforced  through- 
out. The  usual  arrangement  of  the  lights  is  such  that  the  warn- 
ing sign  is  visible  to  the  user  of  the  road  approaching  the  cross- 
ing from  either  direction. 


Fig.  2166.    Illuminated  Highway  Crossing  Signal.     C.  F. 

Massey   Company.    (Using   Railroad    Supply 

Company's  Locomotive  Type  Bell.) 


Fig.   2167.     Reinforced    Concrete    Crossing   Signal.     C.   F. 

Massey    Company.    (Using   Railroad    Supply 

Company's  Locomotive  Type  Bell.) 


Figs.  2168-2175 


HIGHWAY  CROSSING  SIGNALS. 


Fig.  2170.  Model"A" 
Faraday  "High- 
Power"  Enclosed 
Type  Gong.  Stan- 
ley &  Patterson. 


Fig.  2171.  Model"B" 
Faraday  "High- 
Power"  Enclosed 
Type  Gong.  Stan- 
ley &  Patterson. 


Figs.  2168-2169.     Bells  and  Posts.     Showing  Two  Methods 

of  Supporting.     (Bell  Posts  are  made  of  I  Beams.) 

Railroad  Supply  Company. 


Fig.  2172.  Model  "CC" 
"High-Power"  E  n  - 
closed  Type  Gong. 
Stanley  &  Patterson. 


Fig.      2173.        Faraday 
"High-Power"  Skele- 
ton  Bell.     Stanley  & 
Patterson. 


ENCLOSED   CROSSING  BELLS. 

Pigs.  2174  and  2175  show  the  enclosed  type  of  crossing  bell 
made  by  the  Bryant  Zinc  Co.  The  movement  is  enclosed  in 
a  dust  and  weatherproof  case.  All  moving  parts  are  held  in 
place  by  spring  cotters.  Contacts  are  platinum  to  platinum. 
The  standard  winding  of  magnets  is  10  ohms.  These  bells 
can  be  operated  on  any  circuit  from  two  volts  to  650  volts. 

The  style  A  bell  is  designed  for  mounting  to  side  of  post  or 
building.  The  style  B  bell  is  designed  to  be  placed  on  top 
of  a  3  in.,  3%  in.  or  4  in.  pipe  post.  The  gong  is  12  in.  in 
diameter. 


Fig.  2174.    Bell  for  Side  of  Pole.    Bryant  Zinc  Company.       Fig.  2175.     Bell  for  Top  of  Pole.     Bryant  Zinc  Company. 


HIGHWAY  CROSSING  SIGNALS. 


Figs.  2176-2184 


Section.  Complete  Bell.  Section  Through  Magnet. 

Figs.  2176-2178.     Locomotive  Type   Crossing  Bell,   Showing  Two  Views  of  Its  Operating  Mechanism.     Railroad  Sup- 
ply Company. 


RAILROAD    SUPPLYCOJ 
CHICAGO 

PATENTED  NOV5T901 

/OTHEBPATENTS  I 
, /  PEMOfNC  f 
V  AAZ. 


-AA1 


AA2— * 


CHICAGO-' 

'  i'l  U  L  L  L  If  I 

Ulfcfeffff 


2180.      Operating    Mechanism 
of  Locomotive  Type  Bell. 


Fig.  2179.    Sectional  View  of  Loco- 
motive Type  Bell  Mechanism. 


— AA  15 

^f£|MM^ 

Fig.  2181.     Chicago  Highway  Cross- 
ing Signal  Sty4e  "AA."     Rail- 
road Supply  Company. 


Fig.  2182.     Highway  Crossing  Bell 

Style   "A."    Railroad   Supply 

Company. 


Fig.  2183.    Style  "CC"  Bell  for  Top 

of  Post.     Railroad  Supply 

Company. 


Fig.    2184.      Style    "CC"    Bell    for 
Side  of  Post.     Railroad  Sup- 
ply  Company. 


Figs.  2185-2192 


HIGHWAY  CROSSING  SIGNALS. 


Fig.  2185.  Style  "C"  Bell  with 
Fittings  to  Clamp  to  Top  of 
Post.  Railroad  Supply  Company. 


Figs.  2186-2189.     Style  "C"  Bell  Mechanism  and  Parts. 
Supply  Company. 


Railroad 


Fig.    2190. 

Style    "CC" 
Bell    Mechanism 
Railroad  Supply 

Company. 


Fig.   2191.      Iron    Case.    Enclosed    Crossing 
United  Electric  Apparatus  Company. 


Bell. 


Fig.  2192.     Enclosed  Water  Tight,  Low 
and  High  Voltage  Highway  Crossing 
Hell.        L'nited      Electric      Apparatus 
Company. 


3i6 


HIGHWAY   CROSSING    SIGNALS. 


Figs.  2193-2207 


Fig.  2193.     Crossing  Bell.     Bryant  Zinc  Company. 


Figs.  2194-2195.     Bell  and  Case.     Railroad  Supply 
Company. 


Note. — The  Illuminated  Signal,  Fig.  2196, 

is  Made  to  Fit  the  Standard  Bell 

Posts,   Which  Are   Shown   in 

Figs.  2156-2159. 


Fig.   2196.     Illuminated   Signal   for   Highway    Crossing   Signals. 
Railroad    Supply   Company. 


Figs.    2197-2206.      Style    "A"    Skeleton    Bell     Parts.      Railroad 
Supply    Company. 


Fig.  2207.    Double  Gong  Bell. 


Figs.  2208-2215 


HIGHWAY    CROSSING    SIGNALS. 


Fig.  2210.     Style  "X"  Skele- 
ton Bell.     Railroad  Sup- 
ply Company. 


Figs.    2208-2209.      Combination    Bell   and    Relay    Box.      Railroad  Supply  Company. 


CLOCKWORK    BELL    OPERATING    MECHANISM. 

la  Figs.  2211  and  2212  the  clockwork  mechanism  is  actuated 
by  the  train  passing  over  a  short  track  circuit  or  a  track 
instrument  (see  "Circuit  Controllers")  situated  at  a  suitable  dis- 
tance from  the  crossing. 


The  connection  between  the  starting  point  and  the  relay  or 
"register"  is  made  by  line  wires,  and  the  instrument  is  set 
so  as  to  keep  the  bell  circuit  closed  a  predetermined  length 
of  time,  which  can  be  varied  from  20  seconds  to  three 
minutes,  as  may  be  convenient. 


Fig.     221 1.       The     O'Neill     "Register,"     a     Clockwork 
Mechanism,  Performing  the  Same  Kind  of  Work  as 
the    Relay    Shown    in    Fig.    2212.      Railroad    Supply 
Company. 


Fig.  2212.    Escapement  Relay.    Railroad  Supply  Company. 


Figs.  2213-2214.     Electric  Light  for  Highway  Crossing 
Signal. 


Fig.  2215.    Double  Gong  Highway  Crossing  Bell. 
Supply  Company. 


Railroad 


HIGHWAY    CROSSING    SIGNALS. 


Figs.  2216-2224 


Fig.  2217.    Cast  Iron  Bell  Case 
and  Cover.   The  Union  Switch 
and  Signal   Company. 


Fig.  2216.     Iron   Crossing   Sign 
and  Instrument  Case.    Bry- 
ant Zinc  Company. 


Fig.  2218.    Cast  Iron  Bell  Case 
and  Cover.   The  Union  Switch 
and  Signal   Company. 


Fig.    2219.      Bell   Armature   and 

Contacts.      The    Railroad 

Supply  Company. 


Fig.  2220.     Bell  Mounted  in  Cast 

Iron  Case.     The  Railroad 

Supply  Company. 


Fig.   2222.     Crossing   Bell,   with 

12-in.    Steel    Gong,    Enclosed 

Mechanism,  for  Use  on   Iron 

Pipe  Post.    The  Union  Switch 

&  Signal  Company. 


Fig.  2221.     Skeleton  Frame  Bell, 
with  12-in.  Gong.    The  Rail- 
road Supply  Company. 


Fig.  2223,  Bell,  with  12-in.  Steel 

Gong.    The  Union  Switch 

&  Signal  Company. 


Fig.  2224.    Bell,  with  lo-in.  Steel 

Gong.    The  Union  Switch 

&  Signal  Company. 


Figs.  2225-2230 


HIGHWAY  CROSSING  SIGNALS. 


THE    UNION    ELECTRIC    CROSSING    GATE. 

The  crossing  gate  Illustrated  is  built  in  any  required  length 
up  to  50  ft.  either  with  or  without  sidewalk  arms.  The  wooden 
arms  are  well  braced  and  trussed,  and  are  provided  with  spring 
stop  rods  to  cushion  the  blow  when  the  gate  comes  to  the  hori- 
zontal stop  position. 


Fig.     2228.     Electric     Crossing    Gate. 
Signal   Company. 


Union     Switch    & 


The  mechanism  is  mounted  in  a  strong  cast-iron  case  pro- 
vided with  doors  so  that  the  mechanism  is  easily  accessible. 

The  gate  motor  illustrated  is  operated  by  110-volt  d.  c.  cur- 
rent and  Is  controlled  by  a  double-pole,  double-throw  switch. 
The  motor  may  be  either  a.  c.  or  d.  c.,  the  standard  for  d.  c. 
work  being  110  volts,  and  for  a.  c.  work  110  volts,  25  at 
60-cycle,  single-phase. 


Fig.  2225.    Highway  Crossing  Alarm.    Hall  Signal  Co. 


Fig.  2229.    G.  R.  S.  Model  "2A"  Crossing  Signal,  Showing 
Control    Battery    and    Case.      Long- 
Island  Railroad. 


Fig.     2226.      Electric     Crossing     Gate.       Lake     Shore     & 

Michigan     Southern     Railway.       General 

Railway  Signal  Company. 


f 


Fig.   2227. 


v  6;":.V  ,'/,';'  ::'-A' Y>v /fiTT:-?  ,^.:f35^K«& 

Crossing  Gate   Mechanism. 
Company. 


Railroad   Supply 


Fig.  2230.  Highway  Crossing  Signal 
Using  Model  "2A"  Mechanism. 


320 


HIGHWAY    CROSSING   SIGNALS. 


Figs.  2231-2232 


Fig.  2231.     Highway   Crossing  Alarm  Using  Hall   Disk   Signal.      Hall   Signal  Company. 


TRACK  INSTRUMENT  CROSSING  SIGNAL. 


HOESCHEN     SYSTEM. 

The  motive  power  used  to  operate  this  bell  is  obtained  from 
the  natural  spring  of  the  rail,  which  is  utilized  by  means  of 
levers  placed  under  the  base  of  the  rail. 

Seven  different  types  of  this  signal  are  made.  Where  cross- 
Ings  adjacent  to  stations  are  protected,  or  'Where  more  or  less 
switching  is  done,  it  is  possible  to  place  the  starting  generators 
so  that  the  bell  does  not  ring  when  the  train  is  standing  on  the 


Figs.  2233-2235  shows  the  selective  magneto  generator  with 
cover  "A"  removed. 

"B"  represents  the  armature  at  rest  on  the  induction  coils 
"C"  "C,"  which  are  fastened  to  the  poles  of  a  group  of  three 
permanent  magnets  "D"  "D." 

"E"  represents  the  armature  rocker  tripping  pin,  which  rests 
on  the  upper  ends  of  the  two  vertical  rods  "F"  and  "G ;"  the 
lower  ends  of  which  rest  on  top  of  the  ends  of  scale  levers  "O" 


Fig.  2232.     Selective  Magneto  Generator  Installed  Ready  for   Operation.     Hoeschen   Manufacturing   Company. 


main  track  during  the  time  the  engine  is  switching  in  the  yards. 
The  bell  automatically  cuts  out  when  the  train  comes  to  a 
standstill,  and  does  not  begin  to  ring  again  until  the  train 
Is  in  motion,  approaching  the  crossing. 

The  type  "50-B"  bell  is  especially  designed  for  use  on  double 
track  as  it  continues  'to  ring  as  long  as  there  is  a  train  in 
motion  approaching  the  crossing  on  either  track. 

An  illuminated  sign  which  will  remain  illuminated  only  while 
the  bell  is  ringing  may  be  used  in  connection  with  these  bells. 

Fig.  2232  is  a  general  view  of  the  selective  magneto  generator 
Installed  ready  for  operation.  Any  number  of  these  generators 
may  be  placed  the  desired  distance  each  way  from  the  crossing 
on  the  track  or  tracks  to  be  protected.  They  are  connected  In 
series  with  the  releasing  magnets  controlling  the  bell  motor  by 
a  metallic  circuit. 


and  "S,"  which  are  termed  "operating"  and  "shunt,"  and  are 
placed  in  a  "V"  shaped  position  with  their  outer  ends  resting 
firmly  against  the  under  side  of  rail ;  their  inner  ends  converging 
under  base  of  generator  supporting  rods  "G"  and  "F."  These 
levers  being  fulcrumed  close  to  the  rail  multiply  the  slight 
depression  of  the  rail  (caused  by  a  passing  train)  which  is 
usually  -fa  in.  at  a  ratio  of  1  to  12,  thus  giving  the  inner  ends  of 
levers  "O"  and  "S"  an  upward  stroke  of  about  %  in.,  which  is 
sufficient  to  operate  or  shunt  the  generator  as  may  be  required. 

"K"  "K"  represent  the  housings  containing  spiral  compression 
springs  with  plungers  resting  on  scale  levers  "O"  and  "S"  and 
are  used  to  increase  or  decrease  the  tension  of  these  levers. 

Two  line  wires  lead  out  from  the  induction  coils  on  the  op- 
posite side  through  a  lightning  arrester,  thence  to  wires  "W" 
"W,"  which  are  trunked  to  the  telegraph  line,  thence  to  the  bell. 


Figs.  2233-2235 


HIGHWAY  CROSSING  SIGNALS. 


321 


"S"  "S"  represent  heavy  spiral  springs,  which  are  placed  oo 
the  two  bolts  holding  the  generator  base  to  the  cross  plank  "P." 
These  springs  protect  the  mechanism  from  excessive  vibration, 
which  may  be  caused  by  flat  wheels  pounding  the  rail  directly 
over  the  levers  "O"  and  "S." 

Fig.  2234  shows  the  selective  magneto  generator  as  operated  by 
a  car  or  train  moving  toward  the  bell.  As  a  car  or  train,  mov- 


in  contact  with  the  armature  "B"  with  sufficient  force  to  sep- 
arate armature  "B"  quickly  from  the  poles  of  the  induction  coils 
"C"  "C,"  thus  generating  a  momentary  current  of  high  voltage 
which  is  transmitted  over  the  wires  "W"  "W"  to  the  releasing 
magnets  of  the  bell  motor. 

Fig.  2235  shows  the  selective  magneto  generator  shunted  by  a 
car  or  train  moving  in  the  opposite  direction  from  the  bell.  As 
a  car  or  train,  moving  from  the  crossing,  passes  over  the  track 


Fig.     2233.      Selective     Magneto     Generator     with     Cover 

Removed   Showing  Mechanism.     Hoeschen 

Manufacturing  Company. 

ing  toward  the  crossing,  passes  over  the  track  opposite  the 
generator,  levers  "O"  and  "S"  are  so  arranged  that  the  operat- 
ing lever  is  always  depressed  slightly  in  advance  of  the  shunt 


Fig.   2234.     Selective  Magneto  Generator  Being   Operated 

by  Train  Moving  Toward  the  Bell.     Hoeschen 

Manufacturing  Company. 

opposite  the  generator,  levers  "O"  and  "S"  are  so  arranged  that 
the  shunt  lever  is  always  depressed  slightly  in  advance  of  the 
operating  lever.  The  depression  of  the  shunt  lever  forces  the 


Fig.    2235.      Selective    Magneto    Generator    Being    Operated  by  Train  Moving  Away  From  the  Bell.     Rod  F  Pre- 
vents  E  from   Engaging  with   B,   Preventing  the    Generating  of  the  Momentary  Current  in  Coils  CC. 

Hoeschen  Manufacturing  Company. 


lever.  The  depression  of  the  operating  lever  forces  the  vertical 
rod  "G"  upward,  thus  imparting  both  an  upward  and  inward 
motion  to  the  armature  rocker  tripping  pin  "E,"  which  brings  it 


vertical  rod  "F"  upward,  thus  imparting  both  an  upward  and 
outward  motion  to  the  armature  rocker  tripping  pin  "E,"  which 
causes  it  to  pass  by  the  end  of  armature  "B"  so  that  the  depres- 


322 


HIGHWAY  CROSSING  SIGNALS. 


Figs.  2236-2238 


sion  of  the  operating  lever,  immediately  following,  has  no  actuat- 
ing effect. 

Fig.  2239  shows  the  bell  installed  ready  for  service  with  the 
spring  motor  equipped  for  single  track  with  both  time  and 
automatic  cut-out  attachments  ;  also  the  arrangement  of  the  bell 
crank  levers  and  connecting  rods  used  to  wind  the  motor.  The 
three-in.  pipe  housing  for  the  connecting  rod  from  the  track  to 
the  bell  may  be  lowered  and  entirely  covered  with  ballast  where 
necessary.  The  motor  is  compactly  built,  and  the  few  parts  for 
Its  construction  consist  of  a  simple  gear  movement  of  three 
wheels  used  in  connection  with  three  powerful  motor  springs. 

Referring  to  Fig.  2241.  the  generators  are  connected  in  series 
with  the  releasing  magnets  "M"  "M"  by  a  separate  metallic 
circuit  running  each  way  from  the  crossing.  Each  pair  of 
releasing  magnets  is  equipped  with  a  pointed  armature  "N"  "N,'' 


ing  motion  to  the  rocker  "R"  "R,"  which  is  connected  direct  by 
rod  "RO"  with  a  pendulum  bell  hammer,  which  at  regular  inter- 
vals strikes  alternately  the  inner  sides  of  a  loud  sounding 
locomotive  type  of  bell  at  the  rate  of  200  strokes  per  minute  for 
a  pre-arranged  time  unless  stopped  by  a  passing  train. 


Fig.  2236. 

Generator 

Details  showing 

Connections  of  Shunt 

and  Operating  Levers. 


DISTANCC        MAGNETO    GENERATOR     TO    RAIL.   4FT-3IN. 


Fig.  2237.    General  View  of  Bell  Installation. 

Showing  Circuit  and  Winding  Mechanism. 

both  of  which  engage  the  releasing  clutch  lever  "L"  in  the  man-  The    motor    is    provided    with    both    an    automatic    and    time- 

ner  shown.    Clutch  lever  "L"  holds  the  releasing  lever  "RL"  in  stopping    device.      The    time-stopping    arrangement    operates   as 

the  position   as   shown   when   motor   is   not    in    motion.      When  follows: 

either  of  the  releasing  magnets  is   energized  by   the  operation  When  the  motor  is  released  and  the  escapement  wheel  starts 


Fig.  2238.     Diagram  for  Single  Track  Installation  of  Hoeschen  Bell. 

of  a  generator,  the  armature  "N"  corresponding  lifts  the  clutch  to  turn  from  right  to  left,  it -exerts  a  slight  pressure  on  a 
lever  "L,"  thus  releasing  the  motor  through  lever  "RL."  As  counterweight  which  is  fastened  to  the  inner  end  of  the  "RL" 
the  escapement  wheel  turns  from  right  to  left,  it  Imparts  a  rock-  lever  shaft  directly  over  the  escapement  wheel.  This  movement 


Figs.  2239-2240 


HIGHWAY  CROSSING  SIGNALS. 


323 


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Fig.   2239.     Details   of   Bell,    Connections   to   Rail   and  Winding  Arrangement.     Dotted  Lines  in  Pipe  Show 

Winding   Rods.      Hoeschen   Manufacturing    Company. 


Fig.  2240.     Hoeschen  Bell  on  the  Illinois  Traction  System.    A  Union  Style  "B"  Semaphore  Signal  of  the  Type  Re- 
cently Installed  on  500  Miles  of  the  Illinois  Traction  System    Lines   is   Also    Shown   at   the   Left   of   the   View. 


324 


HIGHWAY    CROSSING    SIGNALS. 


Figs.  2241-2242 


forces  lever  "RL"  to  move  slightly  to  the  left,  where  It  is  locked 
by  latch  lever  "V,"  and  it  remains  In  this  position  until  re- 
leased by  the  sliding  sawtooth  bar  "XX,"  which  is  elevated  one 
notch  or  tooth  for  each  revolution  of  the  escapement  wheel 
by  means  of  the  small  stud  on  the  hub  of  the  escapement 
wheel,  thus  causing  the  upper  end  of  sawtooth  bar  "XX"  to 
raise  lever  "V"  which  allows  lever  "RL"  to  swing  back  to 
normal  by  means  of  the  counterweight,  thus  stopping  the  motor. 
The  bell  can  be  made  to  ring  for  a  longer  or  shorter  time  by 
either  lowering  or  raising  the  sawtooth  bar  "XX"  by  means  of 
the  set  screw  in  the  holes  shown  directly  below  it. 

The  automatic  cut-out  or  stopping  mechanism  is  operated 
simultaneously  with  the  winding  of  the  motor  by  a  passing 
train.  The  slight  depression  of  the  rail  of  1-32  or  1-16  in., 
caused  by  a  passing  train,  imparts  a  rocking  or  reciprocating 
movement  of  the  bell  crank  levers  "BC,"  to  the  connecting  rods 
"BB"  and  the  rods  "RR"  by  means  of  rocker  plate^'RI'"  to  the 
two  winding  arms  "WA"  which  are  provided  with  ratchet  dogs 
on  their  inner  sides  which  actuate  the  ratchet  wheel  and  wind 
the  springs.  This  operation  imparts  a  reciprocating  motion  of 
the  rod  "AA,"  which  is  fastened  to  the  right  winding  arm  "WA" 
and  connected  by  friction  clutch  lever  "PC"  to  latch  lever  "V,"' 
thus  releasing  the  "RL"  lever,  which  moves  back  to  normal  by 
means  of  its  counterweight,  which  locks  the  escapement  wheel 
and  stops  the  motor. 

Provision  is  made  to  prevent  over-winding ;  as  the  motor  is 
always  nearly  or  entirely  wound,  and  when  once  fully  wound,  it 
will  deliver  about  20,000  strokes  on  the  bell  and  will  run  con- 
tinuously for  one  hour  and  forty  minutes. 

The  process  of  winding  is  as  follows : 

As  the  motor  springs  are  wound  up,  they  gradually  overcome 
the  counteraction  of  the  springs  "SA,"  which  causes  the  wind- 
Ing  arms  "WA"  to  sag  down  about  %  in.  so  that  the  shoulders 
on  the  lower  ends  of  the  winding  rods  "RR"  cannot  be  engaged 
by  the  reciprocating  motion  of  the  rocker  winding  plate  "R^?." 
When  the  motor  springs  commence  to  unwind,  the  springs  "SA" 
lift  the  winding  arms  "WA"  which  raises  the  winding  rods  "RR" 
so  that  the  shoulders  on  the  lower  ends  of  these  rods  are  again 
brought  in  contact  with  the  rocker  winding  plate  "RP"  which 
allows  the  motor  springs  again  to  wind  when  a  train  passes  over 
the  winding  lever. 

A  small  dial  with  pointer  is  shown  on  the  face  of  the  motor. 
This  indicates  to  the  signal  maintainer  the  amount  of  potential 
energy  stored  up  ready  for  service. 


Names  of  Parts,  Hoeschen  Bell;  Fig.  2241. 

AA  Stopping  Rod 

FC  Friction  Clutch  Lever 

L  Releasing  Clutch  Lever 

MM  Releasing  Magnets 

N  Armature 

NN  Pointed  Armature 

R  Rocker 

RL  Releasing  Lever  for  Motor 

RP  Rocker  Plate 

SA  Springs 

V  Latch  Lever 

WA  Winding  Arms   (Rigfa  and  Left) 

XX  Sliding  Bar  (for  Raising  Lever  V) 


Fig.  2241.     Details  of  Bell  Mechanism, 
facturing  Company. 


Hoeschen  Manu- 


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Fig.  2242.    Arrangements  of  Crossing  Bell  for  Double  Track.     Non-Selective  Generators  Used. 

Hoeschen   Manufacturing  Company. 


ACCESSORIES.  325 


ACCESSORIES 
Pages  326-518  Figures  2243-3899 

Pages          Figures 

BATTERIES 326-345  2243-2415 

STORAGE 326-334  2243-2296 

PRIMARY 335-340  2297-2351 

BATTERY  CONNECTORS,  ELEVATORS  AND  SHELTERS       .     .  340-345  2352-2415 

CIRCUIT  CONTROLLERS       346-362  2416-2549 

SWITCH 346-353  2416-2462 

SIGNAL 354-356  2463-2486 

TRACK,  TOWER  AND  BRIDGE 356-362  2487-2549 

INDICATORS 363-383  2550-2674 

ANNUNCIATORS  AND  TOWER  INDICATORS 363-376  2550-2629 

SWITCH 377-383  2630-2674 

LAMPS,  LANTERNS  AND  ATTACHMENTS 384-391  2675-2743 

LIGHTNING  ARRESTERS       392-397  2744-2788 

LOCKS 398-410  2789-2859 

ELECTRIC  LOCKS 398-401  2789-2812 

ELECTRIC  SWITCH  LOCKS 402-404  2813-2830 

MECHANICAL  TIME  LOCKS  AND  TIME  RELEASES     ....  405-410  2831-2859 

POWER  GENERATION  AND  DISTRIBUTION     ....  411-438  2860-3043 

POWER  UNITS  AND  DYNAMO  MACHINERY       411-417  2860-2889 

POWER  SWITCHBOARDS 417-420  2890-2899 

MERCURY  ARC  RECTIFIERS    . 420-424  2900-2915 

AIR  COMPRESSORS     ...... 424-430  2916-2949 

BATTERY  CHARGING  SWITCHES 430-431  2950-2969 

TRANSFORMERS 432  2970-2977 

REACTANCE  AND  RESISTANCE  UNITS 432-434  2978-2993 

SWITCHES  AND  CIRCUIT  BREAKERS 435-436  2994-3001 

WIRING  AND  DETAILS         436-438  3002-3043 

RELAYS 439-450  3044-3103 

RELAY  HOUSINGS  AND  CABLE  POSTS 451-461  3104-3223 

SIGNALS  AND  FITTINGS       462-477  3224-3478 

SLOTS,  ELECTRO-MECHANICAL 478-480  3479-3492 

SWITCH  MACHINES  AND  SWITCH  STANDS    ....  481-483  3493-3514 

TESTING  INSTRUMENTS 484-489  3515-3558 

TOOLS  AND  APPLIANCES    .  ~ 489-496  3559-3627 

MAINTENANCE 489-490  3559-3577 

MOTOR  CARS 491-494  3578-3593 

TRACK    CIRCUIT  AND  BONDING    TOOLS 495-496  3594-3627 

TRACK  AND  PIPE  LINE  INSULATION 497-500  3628-3690 

TRAIN  STOPS 501-502  3691-3700 

TRUNKING  AND  CONDUIT      503-509  3701-3883 

TRUNKING 503-505  3701-3821 

CONDUIT 506-507  3822-3850 

BOOTLEGS  AND  CONNECTIONS 508-509  3851-3883 

WIRE  510-518  3884-3899 


326 


ACCESSORIES. 


Figs.  2243-2246 


BATTERIES 


STORAGE  BATTERIES 


Storage  batteries  are  divided  into  two  general  classes ;  lead- 
sulphuric  acid  and  two-metal  batteries.  The  lead-sulphuric 
acid  class  has  electrodes  of  peroxide  of  lead  and  finely  divided 
metallic  lead  both  on  lead  supports  in  an  electrolyte  of  dilute 
sulphuric  acid.  It  includes  the  Plante  and  Pasted  (Faure) 
types.  To  the  Plante  type  belong  all  those  lead  batteries  whose 
active  material  is  obtained  by  means  of  chemical  or  electro- 
chemical corrosion  of  the  lead  support,  and  whose  electrolyte 
1?  a  solution  of  sulphuric  acid  and  water.  To  the  Pasted  type 
belong  those  batteries  in  which  the  active  material  consists  of 
paste  made  of  lead  oxides  applied  to  a  grid.  There  are  also 
various  combinations  and  modifications  of  the  above  two  types. 
The  two-metal  class  of  storage  battery  makes  use  of  two  dis- 
similar metals,  as  electrodes  with  an  acid  or  alkaline  electrolyte 
depending  upon  the  particular  type.  The  metal  may  be  either 
in  a  highly  divided  state,  an  oxide  or  a  salt. 

Each  cell  of  a  lead-sulphuric  acid  battery  has  an  electro- 
motive force  on  discharge  of  approximately  two  volts,  and  an 
ampere  hour  capacity  depending  upon  the  number  and  size  of 
plates.  The  energy  capacity  of  the  battery  in  watt-hours  is 
approximately  the  number  of  cells  in  series  multiplied  by  two, 
and  by  the  ampere-hour  capacity  of  the  cell. 


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Figs.  2243-2246.     Diagrammatic  Representation  of  the 

Changes  in  a  Lead-Sulphuric  Acid  Storage  Battery 
During  Charge  and  Discharge. 

A  lead  storage  cell  consists  essentially  of  an  element  compris- 
ing positive  and  negative  plates  placed  alternately  but  grouped 
and  connected  respectively  to  a  positive  and  a  negative  terminal, 
a  dilute  solution  of  sulphuric  acid  and  water  as  an  electrolyte, 
a  containing  jar  and  plate  separators. 

The  changes  taking  place  during  discharge  and  charge  are 
shown  in  Figs.  2243-2246,  where  the  essential  active  elements 
are  represented  diagramatically. 

In  the  charged  battery,  Fig.  2243,  peroxide  of  lead  (PbO2)  sup- 
ported on  a  lead  conducting  frame  is  the  positive  electrode, 
sponge  lead  (Pb)  supported  on  a  similar  frame  is  the  negative 
electrode,  and  a  mixture  of  sulphuric  acid  (H,SO4)  and  water 
(H2O)  is  the  electrolyte.  In  Fig.  2246  the  external  circuit  has 
been  completed  and  current  is  flowing  from  the  positive  plate 
through  the  external  circuit  into  the  negative  plate  through  the 
solution  back  to  the  positive  plate. 

The  lead  peroxide  of  the  positive  plate  is  giving  up  its  oxygen 
and  by  combination  with  the  dilute  sulphuric  acid  is  being 
converted  into  lead  sulphate.  The  lead  of  the  negative  plate  is 
also  combining  with  the  dilute  sulphuric  acid  and  is  being  con- 


verted into  lead  sulphate,  while  water  is  being  formed  by  the 
union  of  the  oxygen  liberated  from  the  positive  plate  with  the 
hydrogen  liberated  from  the  sulphuric  acid.  This  chemical 
action  continues  until  the  sulphate  formed  on  both  plates  re- 
duces the  activity  of  the  remaining  material  (Fig.  2246). 

In  Fig.  2243  the  battery  is  being  charged.  The  positive  and 
negative  terminals  of  a  generator  are  connected  respectively  to 
the  positive  and  negative  terminals  of  the  battery.  Current 
flows  from  the  generator  into  the  positive  plate,  through  the 
solution  to  the  negative  plate  back  to  the  generator.  Here  the 
action  which  takes  place  is  the  reverse  of  discharging.  Lead 
sulphate  from  both  plates  unites  with  the  hydrogen  of  the 
water  to  form  sulphuric  acid,  leaving  finely  divided  metallic 
lead  Head  sponge)  at  the  negative  p:ate,  and  at  the  positive 
plate  lead  combined  with  the  oxygen  liberated  from  the  water 
forming  lead  peroxide.  Thus  at  the  end  of  the  charge  the  bat- 
tery is  practically  in  the  same  state  as  at  the  beginning  of  dis- 
charge. 

The  above  explanation  of  the  action  in  a  lead  storage  battery 
is  known  as  the  sulphation  theory,  and  is  now  generally  held  to 
be   correct.      It    may   be   expressed   by    the   equation  : 
Pb  +  PbO2  +  2II,SO4  =  2PbSO4  +  2H,O. 

Reading  from  left  to  right  this  equation  represents  discharging 
and  reading  from  right  to  left,  charging. 

Storage  batteries  are  coming  into  increasing  use  for  electric 
power  interlocking  plants,  for  operating  drawbridges,  power 
operated  signals,  track  circuits,  signal  lighting,  relays,  indi- 
cators, bells  and  electric  locks.  In  portable  form  they  may 
be  transported  on  cars  to  and  from  the  charging  station  and 
the  point  where  they  are  used  for  supplying  current.  In  the 
stationary  form  for  automatic  signals,  two  sets  of  batteries  are 
installed  at  each  point  and  one  charged  while  the  other  is  dis- 
charged. To  do  this  a  line  wire  is  run  from  the  batteries  to 
the  power  house  and  alternately  connected  to  the  two  sets  of 
batteries,  one  set  being  charged  in  series  while  the  other  set 
is  connected  to  the  signal  apparatus.  An  attendant  goes  over 
the  line  and  throws  the  change-over  switch  whenever  either  set 
of  battery  is  to  be  charged. 


INSTALLATION  AND  OPERATION  OF  STORAGE  BATTERIES  IN 
SIGNAL  SERVICE. 

The  following  instructions  for  installing,  operating  and  car- 
ing for  storage  batteries  were  included  in  the  report  of  the 
Special  Committee  on  Storage  Battery  presented  at  the  1908 
convention  of  the  Railway  Signal  Association. 

Storage  batteries  are  used  in  connection  with  Interlocking 
and  block  signals. 

In  interlocking  plants  the  batteries  are  permanently  located 
at  the  working  points  and  charged  from  a  central  source  of 
power. 

In   automatic  work,    batteries  are   used   in  three  ways : 

(1)  Battery    permanently     located    at    working    point    and 
charged    from    transmission    line. 

(2)  Battery    permanently    located     at    working    point    and 
charged   from   primary   cells. 

(3)  Battery   located   at  working  point   on   discharge  only — 
and  removed  to  power  source  for  recharge. 

The  batteries  for  interlocking  plants,  and  applications  1  and 
2  for  block  signals  are  never  moved  and  are  termed  "station- 
ary batteries." 

The  batteries  for  class  3  in  block  signals  require  a  battery 
which  can  be  readily  handled  and  moved  from  place  to  place 
and  therefore  are  termed  "portable  batteries." 

Installation    of   Stationary   Batteries. 

The  battery  should  be  in  a  space  by  itself  as  the  acid 
fumes  given  off  during  the  charge  are  of  corrosive  nature. 
This  space  should  be  well  ventilated,  well  lighted,  and  as  dry 
as  possible.  If  the  space  is  specially  constructed,  it  should 
contain  no  metal  work  other  than  lead.  If  this  is  not  possi- 
ble, then  such  metal  parts  should  be  protected  by  at  least 
two  coats  of  acid-proof  paint.  The  floors  of  a  large  battery 
room  should  be  preferably  of  vitrified  brick,  jointed  with 
pitch. 

The  batteries  should  be  placed  in  rooms  of  uniform  tempera- 
ture, preferably  70  deg.  F.  Low  temperature  does  not  injure 
a  battery,  but  lowers  its  capacity  approximately  one-half  per 
cent,  per  degree.  Excessively  high  temperatures  shorten  the 
life  of  tfye  plates. 

If  the  batteries  are  in  glass  jars  and  not  of  the  two-plate 
type,  the  following  directions  should  be  observed  in  installing. 

Batteries  up  to  400  a.  h.  capacity  shall  be  placed  in  glass 
jars.  All  batteries  shall  be  for  an  eight-hour  rate  of  discharge 
at  70  deg.  F.. 


Fig.  2247 


ACCESSORIES. 


327 


For  a  battery  of  a  greater  capacity  than  400  a.  h.,  wooden 
tanks  shall  be  required  and  should  be  covered  by  special 
specifications. 

In  batteries  of  a  large  number  of  cells,  such  as  in  inter- 
locking plants,  substantial  wood  racks  should  be  provided 
to  support  the  cells.  These  racks  should  preferably  be  made 
of  long  leaf  yellow  pine  with  non-corrosive  fastenings,  and 
thoroughly  protected  by  at  least  two  coats  of  acid-proof  pnitil. 
The  cells  should  be  arranged  transversely,  and  the  lay-out  of 
cells  should  be  such  that  each  cell  is  accessible  for  inspection 
and  sufficient  head  room  over  each  cell  to  remove  the  element 
without  moving  the  jar. 

Bach  jar  is  set  in  a  tray  which  has  been  evenly  filled  with 
fine  dry  bar  sand,  the  trays  resting  on  suitable  insulators. 

When  placing  the  positive  and  negative  groups  into  the  jars, 
see  that  the  direction  of  the  lugs  is  relatively  the  same  in 
each  case,  so  that  a  positive  lug  of  one  cell  adjoins  and  is 
connected  to  a  negative  lug  of  the  next  cell,  and  so  on  through- 
out the  battery ;  this  insures  the  proper  polarity  throughout 
the  battery,  bringing  a  positive  lug  at  one  free  end  and  a 
negative  at  the  other. 

Before  bolting  the  battery  lugs  together,  they  should  be 
well  scraped  at  the  point  of  contact ;  to insure  good  conductivity 
and  low  resistance  of  the  circuit.  The  connector  studs  should 
be  covered  with  vaseline  before  screwing  up,  and  the  entire 
connections  covered  with  vaseline  or  suitable  paint. 


Fig.  2247.   Storage  Battery  Installation.    Chicago  Term- 
inal.    Chicago  &   North-Western. 

Before  putting  the  electrolyte  into  the  cells,  the  circuits 
connecting  the  battery  with  the  charging  source  must  be  com- 
pleted, care  being  taken  to  have  the  positive  pole  of  the 
charging  source  connected  with  the  positive  end  of  the  bat- 
tery, and  so  with  the  negative  poles.  The  electrolyte  should 
cover  the  top  of  plates  by  one-half  inch. 

Electrolyte.  The  electrolyte  shall  be  of  a  quality  and  spe- 
cific gravity  approved  by  the-  battery  manufacturer. 

If  it  is  not  practicable  to  obtain  approved  electrolyte,  tests 
for  the  purity  of  the  supply  obtained  should  be  made  before 
it  is  used.  Specifications  for  tests  will  be  found  under  heading, 
"Specifications  for  Tests  for  New  Electrolyte." 

Initial  Charge.  The  initial  charge  should  follow  the  manufac- 
turer's instructions.  The  charge  should  be  started  promptly  as 
soon  as  all  the  cells  are  filled  with  electrolyte,  and  all  connec- 
tions made,  usually  at  the  normal  rate,  and  continued  at  the 
same  rate  until  both  the  specific  gravity  and  voltage  show  no 
rise  over  a  period  of  10  hours,  and  gas  is  being  freely  given  off 
from  all  the  plates.  The  positive  plates  will  gas  sometimes  be- 
fore the  negatives.  Generally,  to  meet  these  conditions,  from  45 
to  55  hours'  continuous  charging  at  the  normal  rate  will  be  re- 
quired; and  if  the  rate  is  less,  the  time  required  will  be 
proportionately  increased.  In  case  the  charge  is  interrupted, 
particularly  during  its  earlier  stages,  or  if  it  is  not  started 
as  soon  as  the  electrolyte  is  in  the  cells,  the  total  charge  re- 
quired (in  ampere  hours)  will  be  greater  than  if  the  charge 
is  continuous  and  is  started  at  once. 

As  a  guide  in  following  the  progress  of  the  charge,  readings 
should  be  regularly  taken  and  recorded.  The  gassing  should 
also  be  watched,  and  if  any  cells  are  not  gassing  as  much 
as  the  surrounding  cells,  they  should  be  carefully  examined 
and  the  cause  of  the  trouble  removed.  The  temperature  of 
the  electrolyte  should  be  closely  watched,  and  if  it  approaches 
100  deg.  F.,  the  charging  rate  must  be  reduced  or  the  charge 
temporarily  stopped  until  the  temperature  lowers. 

The   specific   gravity   will   fall    after   the    electrolyte    is    added 


to  the  cells,  and  will  then  gradually  rise  as  the  charge 
progresses,  until  it  is  up  to  1,210  or  thereabouts. 

The  voltage  of  each  cell  at  the  end  of  the  charge  will  have 
risen  to  its  maximum,  and  usually  will  be  between  2.50  and 
2.70  volts,  and  for  this  reason  a  fixed  or  definite  voltage 
should  not  be  aimed  for. 

If  the  specific  gravity  of  any  of  the  cells  at  the  completion  of 
the  charge  is  below  1205,  or  above  1215,  allowance  being  made 
for  the  temperature  correction,  it  should  be  adjusted  to  within 
these  limits,  by  removing  and  adding  electrolyte  If  specific 
gravity  is  low,  and  adding  pure  water  if  the  specific  gravity 
is  high,  to  again  bring  the  surface  at  the  proper  height  above 
the  top  of  the  plates. 

It  is  of  the  utmost  Importance  that  the  initial  charge  be 
complete  in  every  respect. 

Note. — In  the  case  of  batteries  charging  from  primary  cells, 
if  possible,  the  Initial  charge  should  be  given  at  a  place 
where  direct  current  is  available  of  sufficient  voltage  to  carry 
through  the  charge  at  the  normal  rate  (see  general  Instruo- 
tions),  the  cells  being  then  transferred  to  their  permanent 
position. 

Two-Plate  Cells.  The  general  method  of  installation  is  the 
same  as  the  above,  with  the  following  exceptions : 

Each  cell  contains  one  positive  and  one  negative,  the  posi- 
tive of  one  jar  being  solidly  connected  by  a  lead  strap  to 
the  negative  plate  of  the  adjoining  jar,  and  consequently  no 
connectors  are  required.  At  the  ends  of  each  row  there  is  one 
free  positive  plate  and  one  free  negative  plate,  respectively, 
which  constitute  the  positive  and  negative  terminals  of  that 
row.  Connections  to  these  terminals  are  made  with  bolt 
connectors. 

For  the  installation  of  very  large  batteries,  where  tanks 
are  used,  it  is  customary  to  support  the  tanks  on  a  double  tier 
of  glass  insulators.  The  plates  are  shipped  separately  and 
assembled  one  at  a  time  in  the  tank  and  burned  solidly  to  a 
heavy  lead  bus  bar  by  means  of  a  hydrogen  flame.  It  Is 
recommended,  when  installations  of  this  kind  are  required,  that 
the  battery  manufacturers  install  the  battery  in  accordance 
with  their  standard  practice. 

Installation  of  Portable  Batteries. 

Initial  Charge.  The  initial  charge  should  follow  the  manu- 
facturer's instructions.  If,  as  is  the  usual  practice,  the  battery 
is  shipped  with  the  electrolyte  (solution)  in  the  cells,  im- 
mediately upon  receipt  remove  the  vent  plugs  from  each  cell, 
and  if  the  electrolyte  does  not  cover  the  plates  add  sufficient 
pure  water  until  the  plates  are  covered  %  inch.  Although 
the  battery  is  fully  charged  before  shipment,  it  is  advisable 
to  give  it  a  five-hour  charge  at  the  normal  rate,  as  given  on 
the  name  plate. 

If,  however,  the  battery  is  shipped  "dry"  or  without  the 
electrolyte  in  the  cells,  and  equipped  with  rubber  separators, 
it  should  be  usually  put  in  service  as  follows:  Fill  the  cells 
slowly  with  electrolyte  of  1170  specific  gravity  (see  note)  until 
the  plates  are  covered  one-half  (%)  inch,  and  then  Immedi- 
ately start  the  charge  at  one-half  the  normal  rate,  and  continue 
until  the  voltage  of  each  cell  has  ceased  to  rise  and  the  cells 
have  been  gassing  freely  over  a  period  of  10  hours,  and  there 
is  no  further  rise  in  the  specific  gravity  over  the  same  period. 
About  70  hours  at  one-half  the  normal  charge  rate  will  be 
required  to  complete  the  charge;  if  the  rate  is  less  than 
this,  the  time  required  will  be  proportionately  increased.  If 
the  temperature  of  the  electrolyte  rises  to  110  deg.  F.  during 
the  charge,  the  current  should  be  reduced  or  stopped  until 
it  lowers.  After  the  completion  of  the  charge,  adjust  the  spe- 
cific gravity  to  between  1275  and  1300,  with  the  electrolyte 
at  the  proper  height  (one-half  inch  above  the  plates). 

Note. — If  the  battery  is  assembled  on  the  ground,  and  wood 
separators  are  used,  then  the  electrolyte  used  for  filling  should 
be  of  1210  sp.  gr.  If  rubber  separators  are  used,  the  electrolyte 
used  for  filling  should  be  1710  sp.  gr. 

Routine  Instructions  for  the  Operation  and  Care  of  Storage 
Batteries  in  Interlocking  Plants. 

Pilot  Cell.  In  each  battery,  select  a  readily  accessible  cell, 
to  be  used  in  following  the  daily  operation  of  the  battery, 
by  taking  specific  gravity  readings  of  the  electrolyte,  as  given 
below.  Keep  the  level  of  the  electrolyte  of  this  cell  at  a  fixed 
height,  one-half  inch  above  the  top  of  the  plates,  by  adding  a 
small  quantity  of  pure  water  each  day;  this  is  extremely 
important. 

Charging.  As  a  general  rule,  do  not  charge  until  the  gravity 
of  the  pilot  cell  has  fallen  at  least  10  points  (.010  sp.  -gr.) 
below  the  preceding  overcharge  maximum  (see  "Overcharge" 
below),  the  battery  being  then  about  one-third  discharged. 

In  any  case,  charge  as  soon  as  possible  after  reaching  either 
of  the  limits  given  below  under  "discharging,"  or  if  for  any 
reason  a  heavy  discharge  is  expected. 


328 


ACCESSORIES. 


Regular  Charge.    Charge  at  the  normal  rate  of amperes, 

or  as  near  as  possible,  and  continue  until  the  gravity  of  tho 
pilot  cell  has  risen  to  three  points  below  the  maximum  reached 
on  the  preceding  overcharge,  when  the  charge  should  be 
stopped;  for  example,  if  the  maximum  gravity  on  the  over- 
charge is  1207,  the  gravity  reached  on  regular  charge  should 
be  1204.  The  cells  should  be  all  gassing  moderately. 

Overcharge.  Once  every  two  weeks,  on pro- 
long the  regular  charge  until  15-minute  readings  of  the  gravity 
of  the  pilot  cell  and  of  the  battery  voltage,  taken  from  the 
time  the  cells  begin  to  gas,  show  no  rise  on  five  successive 
readings,  thus  having  been  at  a  maximum  for  one  hour. 

Note. — When  the  above  method  of  overcharge  is  not  prac- 
ticable, the  overcharge  may  be  given  every  sixth  charge,  pro- 
vided the  battery  receives  an  overcharge  at  least  once  every 
month.  If-  In  following—Has- -method,  i.  e.,  where  the  over- 
charee  Is  given  at  intervals  longer  than  two  week?-  and  not 
less  frequently  than  once  a  month,  the  regular  charge  should 
be  prolonged  until  one-half  hour  readings  of  the  gravity  of 
the  pilot  cell  and  of  the  battery  voltage,  taken  from  the  time 
the  cells  begin  to  gas,  show  no  rise  on  seven  successive  read- 
Ings,  thus  having  been  at  the  maximum  for  three  hours.  The 
cells  should  all  be  gassing  freely.  The  overcharge  should  be 
given  whether  the  battery  has  been  in  regular  use  or  not. 

Charging  in  Series.  If  two  or  more  batteries  are  charged 
together  in  series,  care  should  be  taken  that  each  battery 
Is  cut  out  at  the  proper  time;  in  other  words,  if  one  of  the 
batteries  discharges  less  than  the  other,  it  should  not  receive 
as  much  charge. 

Discharging.  Never  allow  the  gravity  of  the  pilot  cell  to 
fall  more  than  about  30  points  below  the  preceding  overcharge 
maximum.  As  a  rule,  do  not  allow  gravity  to  fall  more  than 
20  points. 

Never  allow  the  voltage  to  go  below  1.85  volts  per  cell  when 

discharging  at  the  normal   rate    ( amperes).     If  the  rate 

of  discharge  is  less  than  the  normal  rate,  the  voltage  should 
not  be  allowed  to  go  so  low. 

Limiting  voltage cells volts. 

Never  allow  the  battery  to  stand  in  a  completely  discharged 
condition. 

Readings.  Read  and  record  the  gravity  of  the  pilot  cell  and 
battery  voltage  just  before  the  start  and  the  end  of  every 
charge,  together  with  the  temperature  of  the  electrolyte. 

To  properly  compare  the  gravity  readings,  they  should  be 
corrected  to  standard  temperature,  70  deg.  F.,  as  follows:  Add 
one  point  (.001)  for  every  three  degrees  above  70  deg.  F.,  and 
subtract  one  point  (.001)  for  every  three  degrees  below  70 
deg.  F. 

Once  every  two  weeks,  after  the  end  of  the  charge  preceding 
the  overcharge,  read  and  record  the  gravity  of  each  cell  in 
the  battery. 

Inspection.  Carefully  inspect  each  cell  on  the  day  before 
the  overcharge,  using  a  lamp  on  an  extension  cord  for  the 
purpose.  Examine  between  the  plates  and  hanging  lugs  to 
make  sure  that  they  are  not  touching,  and  also  make  a  careful 
note  of  any  peculiarity  in  color,  etc.,  of  the  plates. 

Use  a  strip  of  wood  or  hard  rubber  in  removing  short 
circuits.  Never  use  metal. 

Towards  the  end  of  the  charge  preceding  the  overcharge,  note 
any  irregularity  of  gassing  among  the  cells  ;  any  which  are  slow 
In  gassing  should  be  investigated. 

Indications  of  Trouble.  Falling  off  in  specific  gravity  or 
voltage  relative  to  the  rest  of  the  cells. 

Lack_pf.  or  slower  gassing  on  overcharge,  as  compared  with 
surrounding  cells. 

Color  of  plates  markedly  lighter  or  darker  than  in  surround- 
ing cells,  except  that  sides  of  plates  facing  glass  may  vary 
considerably. 

In  case  of  any  of  the  above  symptoms  being  found,  examine 
carefully  for  cause,  and  remove  at  once. 

Report  trouble  of  any  description  at  once  to 

Broken  Jars.  If  a  jar  should  break,  and  there  is  no  other 
to  take  its  place,  so  that  the  plates  will  have  to  remain  out 
of  service  for  some  time,  keep  the  negatives  wet  in  a  tub  of 
water  and  allow  the  positives  to  dry.  Connect  into  circuit 
again  just  before  a  charge,  so  that  the  plates  will  receive 
the  benefit  of  the  charge. 

Other  Important  Points.  The  plates  must  always  be  kept 
covered  with  electrolyte.  Use  only  pure  water,  preferably  dis- 
tilled, to  replace  evaporation. 

Never  add  electrolyte  except  under  the  conditions  explained 
In  the  general  instructions. 

Never    allow    the   sediment    to   get    up    to    the    bottom    of    the 
plates;    remove   when   the    clearance   lias    reached  one-half   inch. 
Ventilate  the  room  freely,  especially  when  charging. 
Never  bring  an  exposed  flame  near  the  battery  when  charging. 
Never    allow    metals    or    impurities   of    any    kind    to    pet    into 
the    ce[)s ;    if    such    has    happened,    remove    at    once,    wash    the 
plates  and   replace   the   electrolyte. 


Fill   out  the  report  sheets  regularly. 
Read   the   general    instructions   carefully. 

Routine   Instructions    for    the    Operation    and    Care    of    Storage 
__      Batteries  in  Block  Signal  Service.    Central 

Charging  Plant. 

Charging.    When  to  charge :    Unnecessarily  frequent  charging 
should    be    avoided,    but    to    insure    a    reserve    in    case   of    emer- 
gency  it   is   advisable  not  to   take   out   on    discharge   more   than 
one-third    capacity,    this    being    indicated    by    the    fall    of    the 
specific   gravity    of   the    electrolyte.     The   fall    in    gravity    is    In 
proportion  to  the  ampere  hours  discharged  and  for  a   discharge 
equal    to   one-third    capacity    in    approximately    10   points    (.010 
specific  gravity).     How  frequently  each  circuit  or  series  of  bat- 
teries  should    be   charged    will    be   governed   by  the  battery   in 
the   circuit   having   the  greatest   average  amount  of  discharge 
-  Having  determined  which  battery  first  shows  a  drop  in  gravity 
.  from  full  charge  to  the  regular  working  limit  (not  exceeding  10 
points)     charge    often    enough    to    prevent    the    gravity    of    the 
battery  falling  below  this  limit. 
Regular   Charge.     Charge    at   an   average   rate   of  am 

pe,res    for ho"rs     (this    being    the    time    required    to 

Sring  the  battery  having  the  greatest  discharge  up  to  full 
charge,  as  indicated  by  the  specific  gravity  and  voltage  ceasing 
to  rise). 

Overcharge.  Once  every  two  weeks  prolong  the  regular  charge 
for  three  hours. 

Discharging.  As  a  general  rule,  do  not  continue  the  dis 
charge  after  the  gravity  of  the  battery  receiving  the  most 
discharge  has  fallen  more  than  10  points  from  maximum 
Never,  however,  except  in  case  of  emergency,  allow  the  gravity 
to  fall  more  than  30  points  from  maximum,  or  the  voltage 
below  1.85  volts  per  cell  when  discharging  at  the  normal  rate 

*• amperes).  If  the  rate  of  discharge  is  less  than 

the  normal  rate,  the  voltage  should  not  be  allowed  to  eo 
so  low. 

Readings.  Once  a  month,  on  the  day  before  the  overcharge 
read  and  record  the  gravity  of  each  cell  of  each  battery  on 
the  circuit,  together  with  the  average  temperature  of  the 
electrolyte. 

To    properly    compare    the    gravity    readings,    they    should    be 
corrected  to  standard  temperature,  70  deg.  F.,  as  follows:    Add 
one    point    (.001)    for    every   three    degrees    above    70    deg    F 
and   subtract   one   point    (.001)    for   every   three   degrees   below 
70   deg.   F. 

Inspection.  Carefully  inspect  each  cell,  once  a  month,  on 
the  day  before  the  overcharge.  Examine  between  the  plates 
and  hanging  lugs  to  make  sure  that  they  are  not  touching, 
and  also  make  a  careful  note  of  any  peculiarity  in  color,  etc., 
of  the  plates.  Always  use  a  strip  of  wood  or  hard  rubber 
in  removing  short  circuits.  Never  use  metal. 

In  case  a  battery  or  individual  cell  is  found  to  be  in  poor 
condition,  due  to  overdischarge,  short  circuits,  impurity  in 
the  electrolyte  or  sediment  touching  the  plates,  it  may  be 
well  or  advisable  to  remove  it  to  the  charging  plant  for  treat- 
ment, first  substituting  in  its  place  a  fully  charged  battery 
or  cell,  or  else  a  portable  set  kept  for  the  purpose  (for  treat- 
ment of  low  cells,  see  "General  Instructions"). 

The  instructions  uirder  the  headings  "Indications  of  Trou- 
ble," "Broken  Jars,"  and  "Other  Important  Points"  are  the 
same  as  those  for  Storage  Batteries  In  Interlocking  Plants, 
given  on  this  page. 

Routine  Instructions   for  the   Operation   and   Care  of  Batteries 

in  Signal  Service.     Charging  from  Primary 

Cell. 

Operation.  For  regular  operation,  sufficient  primary  cells 
(connected  either  in  single  series  or  multiple  series)  'should 
be  installed  to  maintain  the  storage  cells  at  approximately  a 
constant  state  of  charge,  as  shown  by  the  specific  gravity  of 
the  electrolyte  remaining  at  about  the  same  point.  If  the 
gravity  falls  off,  there  is  a  lack  of  sufficient  charge.  The 
voltage  per  cell  should  average  between  2.08  and  2.12  volts. 
A  higher  average  than  this  shows  that  the  battery  is  receiving 
too  much  charge,  which  is  also  indicated  by  a  constant  slight 
gassing ;  a  lower  average  voltage  indicates  insufficient  charge, 
resulting  in  the  falling  off  in  gravity  referred  to  above. 

The  gravity  of  the  cells  operating  as  above,  in  a  fully 
charged  state,  should  be  between  1205  and  1215  at  normal 
temperature  (70  deg.  F.)  and  with  the  electrolyte  one-half 
inch  above  the  plates.  Should  there  be  an  unusual  drop  in  the 
gravity,  say  from  10  to  15  points  (.010  to  .015  sp.  gr.)  below 
the  normal,  or  of  the  voltage  below  1.95  volts  per  cell,  the 
cause  should  be  investigated. 

Readings.  At  intervals,  not  exceeding  one  month,  read  and 
record,  on  a  suitable  form,  the  gravity  and  voltage  of  each 
storage  cell,  together  with  the  temperature  of  the  electrolyte, 
and  by  means  of  a  portable  ammeter  read  and  record  the 
charging  current  delivered  from  the  primary  cells. 

To    properly    compare    the    gravity    readings,    they    should    be 


Figs.  2248-2249 


ACCESSORIES. 


329 


corrected  to  standard  temperature  (70  deg.  F.),  as  follows: 
Add  one  point  (.001)  for  every  three  degrees  above  70  deg. 
F.,  and  subtract  one  point  (.001)  for  every  three  degrees  below 
70  deg.  F. 

Inspection.  At  the  time  the  readings  are  taken,  inspect  each 
storage  cell,  examining  between  the  plates  and  hanging  lugs 
to  make  sure  that  they  are  not  touching,  and  also  make  a 
careful  note  of  any  peculiarity  in  color,  etc.,  of  the  plates. 

Always  use  a  strip  of  wood  or  hard  rubber  in  removing  short 
circuits.  Never  use  metal. 

See  that  the  cell  connections  are  clean  and  tight. 

In  case  a  battery  or  individual  cell  is  found  to.  be  in  poor 
condition,  due  to  overdischarge,  short  circuits,  impurities  in  the 
electrolyte,  or  sediment  touching  the  plates,  it  will  be  ad- 
visable to  remove  it  to  some  central  point  where  it  can  be 
treated  to  better  advantage,  substituting  in  its  place  a  fully 
charged  battery  or  else  a  portable  set  kept  for  the  purpose. 

The  instructions  under  the  headings  "Indications  of  Trou- 
ble," "Broken  Jars"  and  "Other  Important  Points"  are  the 
same  as  those  for  storage  batteries  in  interlocking  plants,  given 
on  page  328. 

Routine   Instructions   for  the   Operation   and   Care   of  Portable 
Storage  Batteries  in  Signal  Service. 

When  to  Charge.  Charge  each  battery  frequently  enough  to 
keep  the  specific  gravity  of  the  electrolyte  from  falling  more 
than  80  points  (.080  sp.  gr.)  below  what  it  read  when  fully 
charged,  the  battery  then  being  about  two-thirds  discharged. 
For  Instance,  if  the  gravity,  when  fully  charged,  is  1300,  do 
not  allow  it  to  fall  below  1220'. 

In  any  case,  the  battery  should  be  charged  once  a  month, 
whether  it  is  in  use  or  not.  If  the  battery  has  been  Idle, 
it  should  be  charged  before  putting  into  service  again. 

Charging.  Remove  the  vent  plugs  before  charging.  Charge 
at  the  rate  of  ....  amperes.  After  the  cells  begin  to  gas,  read 
and  record  the  gravity  and  voltage  of  each  cell  every  two  hours, 
continuing  to  charge  until  three  of  these  readings  are  alike. 

If  the  time  for  charging  is  limited,  the  charge  may 

be  started  at  amperes,  reducing  the  rate  to  

amperes  when  the  cells  begin  to  gas,  continuing  the  charge 
until  four  readings  of  the  gravity  and  voltage,  taken  every 
two  hours,  are  alike. 

The  cells  should  all  be  gassing  freely  at  the  end  of  charge. 

Do  not  allow  the  temperature  of  the  electrolyte  to  exceed 
100  deg.  F.,  while  charging.  If  it  tends  to  do  so,  reduce  the 
charging  rate  or  discontinue  charging  until  it  lowers. 

Discharging.  Never,  except  in  case  of  emergency,  allow  the 
gravity  to  fall  more  than  80  points  below  what  It  read  when 
last  charged. 

Readings.  Record,  on  a  suitable  form,  the  specific  gravity  of 
each  battery  before  starting  the  charge  and  at  its  completion, 
Including,  with  the  latter,  voltage  readings  taken  with  the 
charging  current  flowing. 

Electrolyte.  Replacing  evaporation.  Keep  the  plates  well 
covered  with  electrolyte  and  use  only  pure  water  to  replace 
evaporation.  Never  use  electrolyte  for  this  purpose. 

Adjusting  Specific  Gravity.  The  gravity  of  the  electrolyte 
should,  with  the  cells  fully  charged,  be  between  1270  and  1300, 
and  unless  actually  lost  through  spilling  or  a  leaky  jar,  it 
should  not  need  frequent  adjustment.  If,  at  the  end  of  charge, 
the  gravity  does  not  rise  to  its  normal  value,  the  battery 
should  be  carefully  inspected  for  short  circuits  or  other  troubles 
and  If  any  are  found  they  should  be  removed  and  the  charge 
continued  until  gravity  ceases  to  rise.  If  no  short  circuits 
or  other  troubles  are  found,  the  gravity  should  be  brought  up 
to  1300  by  replacing  some  of  the  electrolyte  with  electrolyte 
having  a  higher  gravity.  Should  it  read  above  1300,  it  should 
be  reduced  by  taking  out  a  little  electrolyte  and  replacing  with 
pure  water.  To  accomplish  the  above  result  It  will  generally 
be  found  more  convenient  to  pour  out  all  the  old  electrolyte 
and  replace  at  once  with  new  of  the  proper  gravity. 

General  Care.  After  a  battery  has  been  charged,  the  outside 
of  the  case  and  tops  of  jars  should  be  carefully  cleaned.  The 
connectors  should  be  taken  apart  and  washed  in  a  solution  of 
bl-carbonate  of  soda  and  water  and  rinsed  with  water  and, 
when  dry,  well  oiled. 

The  case  should  also  be  well  oiled  before  sending  the  battery 
out.  Oil  should  never  be  allowed  to  come  in  contact  with  soft 
rubber. 

Once,  each  year,  each  battery  should  be  taken  apart,  the 
sediment  removed  from  the  bottom  of  the  jar,  and  the  plates 
and  separators  lightly  washed  before  replacing.  Any  broken 
or  damaged  parts  should  be  renewed.  Do  not  allow  the  plates 
to  dry.  The  old  electro'yte  can  be  used  again,  adjusting  it  to 
the  proper  gravity  at  "the  completion  of  the  charge,  following 
the  cleaning.  Every  second  cleaning,  it  is  advisable  to  use 
new  electrolyte. 


Indications  of  Trouble.  Falling  off  in  specific  gravity  or  volt 
age  relative  to  the  rest  of  the  cells. 

Lack  of  or  slower  gassing  on  overcharge,  as  compared  with 
surrounding  cells. 

Color  of  plates  markedly  lighter  or  darker  than  In  surround- 
ing cells,  except  that  sides  of  plates  facing  glass  may  vary 
considerably. 

In  case  of  any  of  the  above  symptoms  being  found,  examine 
carefully  for  cause,  and  remove  at  once. 

Important  Points.    Always  fully  charge. 

The  plates  must  always  be  kept  covered  with  electrolyte. 

Use  only  pure  water,  preferably  distilled,  to  replace  evapora 
tion. 

Never  add  electrolyte  except  under  the  conditions  explained 
above. 

Never  allow  the  sediment  to  get  up  to  the  bottom  of  th« 
plates. 


Resistance  W/'re 
-|  /-  Ohm  per  Foot 
I-  Amp.  Capacity 


Hard  Wood  Base 


Figs.    2248-2249.      Adjustable    Resistance    for    Storage 
Battery  When  Used   on  Track  Circuits.     Chi- 
cago,   Milwaukee   &   St.   Paul. 

Ventilate  the  room  freely  when  charging. 

Never  bring  an  exposed  flame  near  the  batteries  when 
charging. 

Never  allow  metals  or  impurities  of  any  kind  to  get  into 
the  cells;  if  such  has  happened,  remove  at  once,  wash  the 
plates  and  replace  the  electrolyte. 

Fill   out   the   record   sheets  regularly. 

Specifications  and  Tests  for  Neic  Electrolyte. 

Color.  The  sample  should  be  absolutely  clear  and  colorless, 
showing  no  dark  color,  due  to  organic  matter.  A  small  amount 
of  lead  sulphate,  sometimes  present,  which  shows  as  a  whitt 
sediment,  will  do  no  harm. 

Odor.  Shake  up  a  closed  flask  or  bottle  partially  filled  with 
the  electrolyte,  then  uncork  and  note  whether  there  is  any 
odor.  Sometimes  sulphurous  or  nitric  acid  can  be  detected  In 
this  manner,  and  the  further  testing  be  very  much  shortened. 

Chlorine.  To  a  sample  of  the  electrolyte  in  a  test  tube  add 
a  few  drops  of  nitric  acid,  then  a  little  silver  nitrate  solu- 
tion. Note  the  appearance  cold,  then  boil.  The  sample  should 
remain  perfectly  clear  when  cold,  and  show  only  a  slight, 
if  any,  turbidity  on  boiling. 

Iron.  To  a  few  cc.  of  the  sample  in  a  test  tube  add  weak 
potassium  permanganate  solution,  drop  by  drop,  until  a  faint 
pink  color  is  permanent.  Then  add  a  little  ammonium  (or 
potassium  sulphocyanate  solution),  when  the  presence  of  iron 
will  be  indicated  by  a  red  color.  It  is  almost  impossible  to 
obtain  acid  which  will  not  show  a  faint  color  by  this  test, 
as  it  is  very  delicate,  but  if  the  color  is  at  all  deep  the  acid 
should  be  rejected  or  else  submitted  for  a  quantitative  analysis. 

Oxides  of  Nitrogen.  Take  about  five  cc.  of  diphenylamin 
solution  (y2  gram  to  100  cc.  c.  p.  sulphuric  acid,  1.84  sp.  gr., 
and  20  cc.  distilled  water)  in  a  test  tube,  and  carefully  pour 
in  about  an  equal  volume  of  the  electrolyte  to  be  tested.  Th« 
presence  of  oxides  of  nitrogen,  or  nitric  acid,  is  shown  by  a 
deep  blue  color  at  the  intersection  of  the  two  liquids. 

Heavy  Metals  (Platinum,  Copper,  etc.),  Arsenic,  Selenium 
and  Sulphurous  Acid.  Treat  about  100  cc.  with  hyrdogen  sul- 
phide until  thoroughly  saturated.  The  solution  should  remain 
perfectly  clear,  and  show  no  color  or  precipitate.  A  negative 
result  shows  absence  of  heavy  metals,  also  arsenic,  selenium 
and  sulphurous  acid.  A  very  slight  separation  of  sulphur 
may  be  neglected,  but  if  the  solution  becomes  quite  turbid, 
sulphurous  acid  should  be  tested  for  as  follows :  Place  some 
of  the  electrolyte  in  a  small  narrow-necked  flask  and  add  some 
finely  divided  pure  zinc.  Test  the  gas  evolved  with  filter 
paper  saturated  with  lead  acetate  solution.  If  the  paper  turni 
brown  or  black,  sulphurous  acid  is  present. 

Note. — It  should  be  understood  that  these  tests  are  for  new 
electrolyte  which  has  not  previously  been  used  in  a  battery. 
If  the  results  obtained  from  any  of  the  several  tests  are  such 
as  to  allow  of  any  uncertainty  regarding  the  suitability  of  the 
electrolyte,  a  sample  (at  least  eight  ounces)  should  be  submitted 
to  the  battery  manufacturer;  likewise  any  samples  of  old  elec- 
trolyte from  cells  in  which  the  presence  of  impurities  is 
suspected. 


330 


ACCESSORIES. 


Figs.  2250-2257 


Type  "BT." 


Type  "ET." 


Figs.  2250-2252.     Three  Types  of  Two-Plate  Cells.    "Chloride  Accumulator." 
Electric   Storage   Battery   Company. 


Positive  Terminal    Plate.  Couple.  Negative  Terminal  Plate. 

Figs.  2253-2255.     Plates   of  Type  "CT"  Cell.     Electric  Storage  Battery  Company. 


Fig.  2256.    Two-Plate  Type  Stationary  Battery  in  Glass 

Jars  for  Operating  Automatic  Signals,  Low  Voltage 

Control  Circuits,  Bells,  etc.— Type  "CT" 

Cells  on  Sand  Tray  "Chloride 

Accumulator." — 


Fig.  2257.     Multiple-Plate  Type  Stationary  Battery  for 

Operating     Electric     Power     Interlocking     Plants, 

Automatic    Signals    and    Track    Circuits,    Low 

Voltage    Control,    Electric    Locks,    etc. — 16 

Cells  on  Rack.  "Chloride  Accumulator." 


Figs.  2250-2257.     Cells  and  Plates.     Electric  Storage  Battery  Company. 


Figs.  2258-2264 


ACCESSORIES. 


2258.     Diagram  of  Battery  Parts.     Electric  Storage  Battery  Company. 

Names  of  Parts,  Storage  Battery.    Fig.  2258. 


A  Copper  Conductor 

B  Lead  Terminal  Lug 

C  Lead-covered  Bolt  Conductor 

D  Glass  Hold-dozvn 

E  Positive  Plate 

F  Negative  Plate 

G  Glass  Jar 


H  Wood  Separator  Dowel 

I  Sand  Tray 

J    Glass  Insulator 

K  Rail 

L  Iron  Bolt 

M  Spacing  Block 

N  Cross  Tie 


O  Dowel  Pin 

P  Brace 

Q  Upright 

R  Vitrified  Brick 

+  Positive  Lug 

—  Negative  Lug 


Fig.   2259.     Type  "E"    13,   in 

Glass    Jar.     "Chloride 

Accumulator.' 


Fig.  2261.     Group  of  Negative 
Plates.    .  Type    "E"     n. 
"Chloride   Accumulator." 


Fig.   2262.     Group   of  Positive 
Plates.      Type     "E"     II. 
"Chloride  Accumulator." 


Fig.    2260.      Type    "F"    15,   in 

Style  A  Glass  Jar  on  Glass 

Tray.      "Chloride 

Accumulator." 


Fig.  2263.     Group    of    Nega- 
tive Plates.     Type  "E"  n 
"Tudor   Accumulator." 


Fig.    2264.    Group  of  Positive 

Plates.       Type     "E"     n 

"Tudor  Accumulator." 


Figs.    2258-2264.      Cells   and   Plates.     Electric   Storage  Battery   Company. 


332 


ACCESSORIES. 


Figs.  2265-2275 


Figs.    2265-2268.      "Exide"    Dismantled    Signal    Cell. 
From  Left  to  Right — Hard   rubber  hold  downs 
for  separators,  perforated  sheet  rubber  sep- 
arators, wood  separator,  negative  group, 
positive  group,  vent  plug,  cover, 
rubber  jar. 


Fig.    2269.     "Exide"     Portable 

Signal  Cell.     Harriman 

Lines. 


Fig.     2270.       "Exide"     Portable     Signal    Battery 
Type    4-SS-g.      Burned    Connections    Be- 
tween   Cells,    Sealed    Top,    Wooden 
Case,   Cover  in    Position. 


Fig.    2271.       "Exide"    Portable     Signal     Battery    Type 
4-SS-9.      Burned    Connections    Between    Cells, 
to    Sealed   Top,   Side   Cut  Away  to  Show 
Construction. 


Fig.   2273.   Wood    Sand   Tray    for 
Glass   Jar  Cells. 


Fig.    2272.      "Exide"    Type     SS7. 

Side  Cut  Away  to  Show  Construction. 


Fig.  2274.     "Exide"  Portable  Signal  Battery  Type  4-SS-Q.  Fig.  2275.     Type  "E"   Glass  Sand  Tray 

Bolted    Connections    Between    Cells.  f°r    Glass   Jar   Cells. 

Figs.  2265-2275.     Signal   Cells.     Electric  Storage  Battery  Company. 


Figs.  2276-2282 


ACCESSORIES. 


333 


Fig.  2281.      Type  "W.  S. 
Couples.     Gould  Stor- 
age Battery  Com- 
pany. 


Fig.  2277.     Positive   Plate.     Willard   Stor- 
age   Battery    Company. 


Fig.    2276.    Type    "DS-5"    Storage    Battery. 
Willard    Storage    Battery    Company. 


Fig.  2282.     Type  "C.  Z."   Cell   Complete.      Gould   Stor- 
age Battery  Company. 


Fig.   2278.     Type  "E-g"    Storage    Battery.     Willard         Fig.     2279.     Negative      Group.     Fig.      2280.      Positive    Group. 
Storage    Battery   Company.  Willard  Standard  Plates.  Willard  Standard  Plates. 


334 


ACCESSORIES. 


Figs.  2283-2296 


EDISON  STORAGE  BATTERY. 

A  cell  Is  one  complete  unit  of  a  storage  battery,  consisting 
of  plates,  electrolyte  and  steel  container.  The  positive  or 
nickel  plate  consists  of  one  or  more  perforated  steel  tubes, 
heavily  nickel  plated,  filled  with  alternate  layers  of  nickel 
hydroxide  and  pure  metallic  nickel  in  exceedingly  thin  flakes. 


sulating  the  complete  element  from  the  steel  container.  At  the 
end  of  element,  that  is,  between  the  outside  negative  plates  and 
the  container,  are  inserted  smooth  sheets  of  hard  rubber.  At 
the  bottom  the  element  rests  upon  a  hard  rubber  rack  or  bridge 
less  than  one  inch  high,  insulating  the  plates  from  bottom  of 
container.  In  the  Edison  cell  no  active  material  is  precipitated. 
The  jar  or  container  is  made  throughout  from  cold  rolled 
sheet  steel  of  fine  quality.  The  container  is  welded  at  the 
seams  by  the  autogenous  method,  making  leakage  or  breakage 


/Ok-_ 


Cell  Completely 
Assembled. 


Top    View     Com- 
plete Cell. 


Positive  and  Neg- 
ative Plates. 


Construction  of  Positive 
and   Negative   Plates. 


Complete       Element 
with    Insulators. 


Figs.  2283-2290.     Views   of  Type  A-4  Cell.     Edison   Storage  Battery    Company. 


The  tube  is  drawn  from  a  perforated  ribbon  of  steel,  nickel 
plated,  and  has  a  spiral  lapped  seam.  This  tube  after  being 
filled  with  active  material  is  reinforced  with  eight  steel  bands, 
equi-distant  apart.  The  tubes  are  held  in  perfect  contact  with 
a  supporting  frame  made  of  cold  rolled  steel,  nickel  plated. 
The  tubes  are  %  in.  In  diam.  and  4%  in.  long.  The  positive 
plate  is  made  in  two  standard  sizes :  Size  "A"  with  30  tubes 
in  two  rows,  and  size  "B"  with  15  tubes  in  one  row. 

The  negative  or  iron  .plate  consists  of  a  grid  of  cold   rolled 
steel,    nickel    plated,    holding    a   number    of    rectangular    pockets 


from  severe  vibration  impossible.  The  cover  is  of  the  same 
quality  sheet  steel,  is  nickel  plated,  and  has  four  mountings, 
two  being  pockets  for  containing  stuffing  boxes  about  the 
terminal  posts.  One  of  the  other  two  is  the  separator,  so 
called  because  it  separates  spray  from  the  escaping  gas  while 
the  battery  is  charging.  The  fourth  mounting  is  an  opening 
for  filling  the  cell  with  electrolyte,  and  for  the  adding  of 
distilled  water  to  take  the  place  of  that  which  evaporates 
during  the  charge.  This  has  a  water  and  air  tight  cap, 
latched  in  place. 


Fig.  2293.  Edison  Cells  Assembled 
in  Trays. 


Figs.    2294  -   2295. 
Positive    and    Nega- 
tive Plates  "B-4"  Cell. 


Fig.     2296.       Type 
"B-4"   Cell    Com- 
plete. 


Figs.    2291-2292.      Vulcanized    Rubber    Insulation    and 

Piece  .Used   for   Insulating   Plates   from 

Bottom  of  Container. 

filled  ^with  powdered  iron  oxide.  These  pockets  are  made  up  of 
very  finely  perforated  steel,  nickel  plated.  After  the  pockets 
are  filled  they  are  inserted  in  the  grid  and  subjected  to  great 
pressure  between  dies  which  corrugate  the  surface  of  pockets 
and  force  them  Into  practically  integral  contact  with  the  grid. 
After  the  plates  are  assembled  into  a  complete  element,  nar- 
row strips  of  treated  hard  rubber  are  Inserted  between  the 
plates,  thereby  separating  and  insulating  them  from  each 
other.  The  side  insulator  is  provided  with  grooves  that  take 
the  edges  of  the  plates,  thereby  separating  the  plates  and  in- 


The  electrolyte  copsists  of  a  21  per  cent  solution  of  potash 
in  distilled  water  with  a  small  per  cent  of  lithia.  The  density 
of  the  electrolyte  does  not  change  on  charge  or  discharge. 

Nothing  but  clean  distilled  water  should  be  used  in  refilling. 
A  special  filling  apparatus  automatically  indicates  when  the 
solution  is  at  required  depth  above  plates. 

Every  metal  part  that  enters  into  the  construction  of  the 
Edison  cell  is  nickel  plated.  The  process  of  nickeling  is  the 
simple  one  of  electroplating,  and  an  annealing  process  fuses 
the  metals  together,  making  them  inseparable. 

The  voltage  of  the  cell  is  1.2  volts.  In  charging  a  voltage  of 
1.85  volts  per  cell  should  be  provided.  The  capacity  of  the 
cell  varies  with  the  size  and  number  of  plates.  The  sizes  in 
most  common  use  are : 

Size.  B-2       B-4     B-6       A-4     A-6     A-8    A-10  A-12 

Nor.  dis.  rate,  amp. .7. 5        15       22.5        30       45        60       75        90 
Ampere    hours    ....  40       80     120         150     225     300     375     450 


Figs.  2297-2311 


ACCESSORIES. 


335 


PRIMARY  BATTERIES. 


GRAVITY    BATTERY 


-  A/o.  /4  Cop/yerMre,  /fv&tief 


Defer//  o/~Z/rrc  Term/rrar/ 


i       /" 
NH 


I       ^^ 

-Jr 


,/" 
4-/~--*> 

^'/s 


^•\(U 

T 


4Lb.Zinc. 
Mercury  Alloy 


I  I 


Figs.  2297-2302.    Gravity  Battery  Details.     New  York 
Central  &  Hudson  River. 


Fig.  2305.   Two-Leaf  Copper  (with  "Turn- 
overs"). 


Figs.   2303-2304.     Three-Leaf   Coppers   (with   two   2-in. 
x  3-in.  "Turnovers"). 


Figs.  2306-2308.     "Pan  Bottom"  Coppers. 


Fig.  2311.    Two-Leaf  Copper  (with  four 
Figs.  2309-2310.    Three-Leaf  Coppers.  x    3-in.    "Turnovers"). 

Figs.  2303-2311.     Types  of  Gravity  Battery  Coppers. 


336 


ACCESSORIES. 


Figs.  2312-2318 


R.    S.    A.    SPECIFICATIONS    FOR    GRAVITY    BATTERY    ZINCS. 

1.  Zincs   shall   be  made  from  virgin  spelter  cast  at  a   low 
temperature   and   shall    be   thoroughly    amalgamated   with   mer- 
cury.   They  shall  be  uniform  in  size  and  weight,  free  from  flaws 
and  mechanical  defects,  and  shall  have  a  smooth  outer  surface. 
A  fracture  of  the.  zinc  must  show  the  grain  firm  and  close. 

2.  The  size  and  shape  of  zincs  shall  conform  closely  to  this 
drawing.    The  brass  binding  post  must  be  firmly  connected  both 
mechanically    and   electrically    to   the   zinc.     The   thumb   screw 
must  be  perfectly   threaded  and   must  fit  closely.      (Figs.   2312- 
2315.) 


fc-16  THREADS 

Figs.  2312-2315.     R.  S.  A.  Standard  Gravity 
Battery  Zinc.     (Zinc,  Binding  Post 

and  Thumb  Screw.) 

The  manufacturer's  name  must  be  cast  on  the  upper  flat 
surface  of  the  zinc  in  as  large  letters  as  the  zinc  will  permit 
and  must  be  raised  not  less  than  3-32-in.  above  the  surface.  In 
addition,  the  manufacturer's  name  or  trademark  must  be 
stamped  on  some  other  part  in  such  a  position  as  not  to  be 
effaced  by  the  action  of  the  electrolyte  or  by  the  process  «f 
cleaning. 

3.  Weight,  the  zincs  shall   weigh  four  pounds  each. 

4.  The  chemical  composition  of  the   finished  zincs   shall  be 
as  follows : 

Mercury    not    less  than  2.00  per  cent. 

Ir°n   not  more  than       .10        " 

Lead    not   more  than       .50 

Other    impurities    not    more  than  .40        " 


5.  When   a   shipment   of   zincs   is    received,   an   examination 
will  be  made  to  see  that  the  physical  requirements  are  fulfilled, 
and    if  found   satisfactory,    one   zinc  from    each    50    or   fraction 
thereof  will  be  taken  for  chemical   analysis.     The  result  of  this 
analysis  shall  determine  whether  the  shipment  will  be  accepted. 

In  the  event  of  controversy  with  the  manufacturer  over  the 
chemical  composition,  one  zinc  from  each  50  or  fraction  thereof 
shall  be  submitted  to  a  disinterested  chemist,  acceptable  to  both 
manufacturer  and  purchaser,  for  an  analysis.  If  in  the  analy- 
sis the  chemical  composition  of  the  zincs  analyzed  is  found  to 
be  in  accordance  with  this  specification,  the  zincs  furnished  will 
be  accepted  and  the  cost  of  the  analysis  shall  be  paid  by  the 
purchaser.  If  the  chemical  composition  is  not  found  to  be  In 
accordance  with  this  specification,  all  expenses  in  connection 
with  the  analysis  including  the  loss  on  the  zincs  analyzed  shall 
be  borne  by  the  manufacturer. 

The  manufacturer  shall  be  advised  of  all  material  rejected 
as  a  result  of  chemical  analysis  or  physical  tests,  and  if  at  the 
expiiation  of  two  weeks  no  instructions  are  received  for  the 
return  of  same,  the  rejected  material  shall  be  returned  at  the 
risk  of  the  manufacturer,  he  paying  the  freight  in  both  direc- 
tions in  either  case. 

The  payment  for  zincs  shall  be  based  upon  the  net  weight 
received. 

6.  Zincs  must  be  carefully  and  securely  packed  in  shavings 
or  sawdust  in  a  stout  barrel  or  box,  in  lots  not  to  exceed  50 
each.    The  name  of  the  manufacturer  and  the  name  of  the  con- 
signee, together  with  the  destination,  number  of  zincs  contained 


CWPER 
RIVET 

-|'HEAI 
8   ~-r: 


J 


a  . 


J 

•nj-* 
M 

L  ' 

i  J 

fi  .t  - 

«•>»  * 

UkriJ 

TWO-LEAF 
COPPER 

1                    1 

9  -  -i-  "3* 

"T  1 

not    less  than  97.00 


Figs.  2316-2318.     R.  S.  A.  Standard  Gravity 
Battery  Copper. 

in  the  package  and  the  purchase  order  number  must  be  plainly 
marked  on  the  outside  of  each  package. 

All  zincs  broken  in  transit  on  account  of  not  being  properly 
packed  will  be  returned  to  the  manufacturer,  who  must  promptly 
replace  same  free  of  cost  to  the  purchaser. 

7.  Thumb  screws  for  binding  posts  shall  be  furnished  only 
when  specified. 

When  furnished  each  box  or  barrel  must  contain  at  least  as 
many  thumb  screws  as  there  are  zincs,  the  thumb  screws  being 
wrapped  separately  and  tied  to  one  of  the  zincs  just  under  the 
cover. 

R.  S.  A.  SPECIFICATIONS  FOR  GRAVITY  BATTERY  COPPER. 

1.  Material,      (a)    Coppers  shall  be  two-leaf  or  three-leaf  as 
specified  and  shall  conform  to  the  above  drawing.     Leaves  shall 
be  No.  30  B  &  S  gauge,  hard  rolled  bright  copper  not  less  than 
98  per  cent  pure.      (Figs.  2316-2318.) 

(b)  Lead  wire  shall  be  No.  14  B  &  S  gauge,  solid  soft  drawn 
copper,   insulated  throughout  the   entire  length,    except  one   In. 
at  each   end.      The  insulation   shall   consist  of  a   3-64-in.    wail 
of  rubber,   shall  adhere  tightly  to  the  wire,  and  shall  be  of  a 
character  suitable  to  withstand  the  action  of  the  battery  solu- 
tion.    Insulation  on  ends  of  wire  to  be  trimmed  either  tapered 
or  square  and   in   this  operation  the  wire  must  not  be  scored. 

(c)  End    of    wire   attached    to    copper   must    be    thoroughly 
cleaned    and   tightly    riveted   as   shown   with  a   rivet   having  a 
%-in.  head  and  a  washer  %-in.  in  outer  diameter.     Both  rivet 
and  washer  shall  be  copper  not  less  than  98  per  cent  pure. 

2.  Packing   and  Marking.      Coppers   shall   be    carefully  and 
securely  packed  In  lots  of  100  each,  or  50  if  so  specified,  and 
the  purchase  order  number,  contents  of  package,  name  of  manu- 
facturer,  and  name  and   address  of  consignee  shall   be  plainly 
marked  on  the  outside  of  each  package. 

3.  Inspection  and  Acceptance.     One  copper  taken  at  random 
from  each  50  or  fraction  thereof  shall  be  examined  and  tested. 


Figs.  2319-2328 


ACCESSORIES. 


337 


"Crowfoot"    Zinc." 


Round    Zinc. 

Figs.    2319-2322.     Types    of 

Gravity  Battery  Zincs. 


Round  Zinc. 


Fig.    2323.      Gravity    Bat- 
tery Jar. 


Fig.  2324.    Gravity  Cell 
Assembled. 


The  results  of  this  examination  shall  determine  whether  the 
lots  so  represented  will  be  accepted.  If  the  samples  are  found 
to  meet  this  specification,  the  material  will  be  accepted.  If  any 
of  the  samples  fail  to  meet  this  specification,  the  lots  repre- 
sented will  be  rejected  and  returned  at  the  risk  of  the  manu- 
facturer, he  paying  the  freight  in  both  directions. 


THE    COLUMBIA    TRACK    BATTERY. 

The  Columbia    track   battery   is   a   primary   caustic   soda   cell 
having  flaky  copper  oxide  as  a  positive  element,  loosely  placed 


the  solution.  This  battery  was  designed  primarily  for  railway 
signal  service  to  replace  the  gravity  or  blue-stone  cell.  It  has 
a  relatively  high  internal  resistance  for  a  caustic  soda  cell,  and 
yet  lower  internal  resistance  than  that  of  the  gravity  cell.  It 
does  not  require  cleaning  or  attention  from  the  time  that  it  is 
put  into  service  until  the  elements  are  exhausted.  On  account 
of  its  construction  and  the  electrolyte  it  will  not  freeze  nor 
evaporate.  Owing  to  its  high  internal  resistance  no  external 
resistance  is  needed  between  the  battery  and  the  track,  and  yet 
it  is  of  sufficiently  low  internal  resistance  so  that  a  severe 


an  11 


190 

DRY 
BATTE 


Fig.  2325.     Columbia  Track  Battery. 
National  Carbon  Company. 


Figs.    2326-2328.      Types    of    Dry    Battery.      Nungesser 
Carbon  &  Battery  Company. 


on  a  tin  disk  to  which  .a.  wire  Is  riveted  for  electrical  connec- 
tion to  the  external  circuit.  The  negative  element  consists  of 
metallic  zinc  properly  amalgamated,  circular  in  form  and  sus- 
pended by  means  of  wires  from  the  edge  of  the  jar  containing 


rainstorm  will  not  make  the  track  insulation  so  bad  that  the 
relay  will  not  hold  up.  The  capacity  of  this  cell  is  350  ampere 
hours  and  it  will  give  service  from  three  to  six  months  on 
tracks.  The  construction  of  the  cell  is  shown  in  Fig.  2325 


338 


ACCESSORIES. 


Figs.  2329-2336 


Fig.    2329.      Schoenmehl    Plate    Type    Copper 

Oxide  Signal  Cell,  400  a.  h.  Waterbury 

Battery   Company. 


Fig.  2330.    R.  S.  A.  Standard  Wing  Nuts  for 
Signal    Battery. 


Fig.   2331.     Track   Battery.      Banks    Electric    &   Manu- 
facturing Company. 


Fig.  2333.  Caustic 
Potash  Battery.  Rail- 
road Supply  Company. 


Fig.  2332.    Signal  Bat- 
tery.      Banks     Electric 
&  Manufacturing  Com- 
pany. 


Figs.  2334-2336.     Gordon  Signal  Cell.     Lutz-Lockwood   Manufacturing   Company. 


Figs.  2337-2351 


ACCESSORIES. 


339 


EDISON-BSCO   CELLS. 

The  plates  used  in  the  Edison-BSCO  primary  battery  are 
made  of  pure  amalgamated  zinc  and  compressed  copper  oxide. 
Each  cell  contains  two  amalgamated  zinc  plates,  forming  the 
positive  electrode  (negative  pole),  and  one  copper  oxide  plate 
constituting  the  depolarizer  and  negative  electrode  (positive 
pole).  The  electrolyte  consists  of  caustic  soda  of  a  special 
grade,  and  water  properly  proportioned. 

When  a  cell  is  on  closed  circuit  and  current  flows,  the  caustic 
soda  is  decomposed  and  the  sodium  is  carried  to  the  oxide  of 
copper  plate,  while  the  oxygen  and  hydrogen  are  carried  to  the 
zinc  plates.  The  oxygon  and  hydrogen  unite  with  the  zinc, 
the  result  of  the  combination  being  hydrated  oxide  of  zinc. 


This  compound  then  dissolves  in  the  free  solution,  and  zincate 
of  sodium  is  formed. 

The  sodium  which  goes  to  the  copper-oxide  plate,  having  a 
stronger  affinity  for  oxygen  than  copper  has  for  oxygen,  takes 
oxygen  away  from  the  copper  oxide  and  combines  with  It  (the 
oxygen),  forming  sodium  oxide.  This  immediately  unites  with 
some  of  the  water  of  the  solution,  reforming  caustic  soda.  The 
amount  of  soda  reformed  in  this  way  is  equivalent  to  the 
amount  decomposed  by  the  current,  so  that  caustic  soda  Is 
used  up  only  as  it  combines  with  hydrated  oxide  of  zinc  to 
form  zincate  of  soda. 

The  action  of  the  cell  gradually  dissolves  the  zinc  plates 
and  converts  the  oxide  of  copper  plate  into  a  plate  of  pure 


Type  401,  400  a.  h.  (Porce- 
lain or  Heat  Resisting 
Glass   Jar). 


Type  402  (Rectangular) 

400    a.    h.     (H.    R. 

Glass  Jars.) 


Type  404  (Barrel  Shaped) 

400  a.  h.  (H.  R.  Glass 

Jars.) 


Figs.  2337-2339.    Edison  BSCO  Batteries.    Thomas  A.  Edison,  Inc. 


PORCELAIN  COVER 


Fig.    2340.      Edison    Type 
"SS"  350  a.  h.  Cell.  Por- 
celain or  H.  R.  Glass 
Jar. 


Fig.  2350. 
Edison    BSCO 

Element 
and   Cover 
Assembled. 


=13 

2i 


r 


POPCIUIH  JAR 


Figs.  2341-2349.     R.  S.  A.  Standard 

Jar,   Cover,   and    Wing   Nut   for 

Signal  Cell. 


Fig.  2351.     Edison  BSCO  Renewal. 


copper  by  taking  away  its  oxygen.  The  copper  oxide  at  the 
surface  of  the  plate  is  the  first  to  be  converted  into  metallic 
copper,  the  reduction  gradually  penetrating  toward  the  cen- 
ter. When  the  cell  is  exhausted  all  but  a  very  thin  layer  of 
black  oxide  of  copper  in  the  center  of  the  plate  is  reduced  to 
metallic  copper.  The  amount  of  unused  oxide  can  be  ascer 
tained  at  any  time  by  picking  into  the  plate  with  a  pen- 
knife. The  portion  that  has  been  exhausted  and  converted  into 
metallic  copper  will  be  red  or  copper  color,  while  the  unchanged 
oxide  of  copper  will  be  black. 

It  follows,  therefore,  that  the  degree  of  exhaustion  which 
the  cell  has  reached  can  be  determined  In  this  way,  but 
its  condition  can  also  be  determined  by  examination  of  the 
zinc  plates,  holes  appearing  in  the  lower  panels  when  the  rated 
capacity  of  the  cell  has  been  discharged. 


34° 


ACCESSORIES. 


Figs    2352-2364 


R.    S.    A.    CAUSTIC   SODA    SIGNAL   CELL. 

The  Railway  Signal  Association  standard  specifications  for 
a  caustic  soda  signal  cell  (see  Figs.  2341-2349)  are  as  follows: 

Complete  Cell.  A  complete  cell  consists  of  a  jar,  cover  and 
renewal  with  one  hexagon  nut,  two  wing  nuts  and  two  washers 
as  shown. 

Renewal.  A  renewal  consists  of  a  sealed  can  of  caustic  soda, 
sealed  bottle  of  mineral  oil  and  assembled  elements  with  con- 
necting wire  and  rigidly  connected  suspension  bolt.  Nuts  and 
washers  shall  be  furnished  with  renewals  only  when  speci- 
fied. 

The  elements  shall  be  so  assembled  that  when  attached  to 
the  cover  and  the  nut  on  the  upper  side  tightened  to  place,  the 
elements  will  be  at  the  proper  height  in  the  solution. 

Connection  to  zinc  shall  be  No.  12  B  &  S  gauge  solid  soft. 
drawn  copper  wire  covered  with  an  insulation  suitable  to  with- 


stand the  action  of  the  oil  and  electrolyte.  Insulation  on  end 
of  wire  shall  be  trimmed  either  tapered  or  square  and  in  this 
operation  the  wire  must  not  be  scored. 

Suspension  bolt  shall  be  iron,  copper  plated. 

Jar  and  Cover.  Jar  and  cover  shall  conform  to  the  dimen- 
sions shown,  with  reasonable  allowance  for  slight  irregularities 
in  manufacture.  Top  of  jar  shall  be  square  with  vertical  axis 
and  cover  shall  be  perfectly  flat.  Manufacturer's  name  or  trade 
mark  may  be  shown  on  cover.  Porcelain  jars  shall  be  glazed 
inside  and  out  and  covers  on  top  and  edge. 

A  solution  line  consisting  of  a  slight  ridge  or  depression 
extending  around  the  inside  of  porcelain  jars  and  the  outside  of 
glass  jars  shall  be  placed  as  shown. 

For  heat  resisting  jars,  glass  shall  be  three-sixteenths  (3-16) 
in.  thick  and  inside  dimensions  shall  be  as  shown  with  reason- 
able allowance  for  slight  irregularities  in  manufacture. 


BATTERY  CONNECTORS,  ELEVATORS  AND  SHELTERS 


Figs.   2352-2356.     Types   of  Battery   Wire   Connectors. 


Figs.  2362-2363.     Wire  Fasteners  for  Battery  Elevator. 

Shown  in  Fig.  2364  (on  left). 

Bryant  Zinc  Company. 


Fig.  2358.  Joint  Between 
Solid  and  Flexible  Wire, 
for  Use  at  Battery  Chutes. 


-24  brass 


Figs.    2357.      Battery    Wire 
Connectors. 


EDGES  HOUNDED 
"ft" 


Fig.  2359.     R.   S.   A.   Standard  Nut 
and  Washer  for  Binding  Post. 


k-%») 

Drawn 
Brass    i 


NolO-24  Brass 


Fig.  2360.    Binding  Post 
for    Copper    Terminal    or 
Gravity  Battery. 


Fig.  2361.    Battery  Con- 
nector  Soldered   to   Wire. 


Fig.    2364.      Battery    Elevators    Showing    a    Common 

Method  of  Wiring  (on  right)  and  an  Improved 

Method  Using  Wire  Fasteners  (on  left). 

Bryant  Zinc    Company. 


Figs.  2365-2371 


ACCESSORIES. 


Fig.  2366.    Wiring  for 
Battery    Elevator.     At- 
chison,    Topeka  &  Santa 
Fe. 


Fig.  2365.    Concrete  Battery  Box.    C.  F.  Massey  Company. 


Fig.  2367.     Cast  Iron  Battery  Box. 


Fig.     2370.       Single     Cast  Fig.    2371.      Double    Cast 
x                    Iron    Battery    Chute.  Iron    Battery    Chute. 

Figs.    2368-2369.      Battery   Box    and    Chute.      Michigan  Bryant    Zinc  Railroad     Supply 

Central.  Company.  Company. 


342 


ACCESSORIES. 


Figs.  2372-2393 


Figs.  2372-2373.   Elevator  and  Standard  Arrangement  of  Cells 
in  Battery  Chute.     Southern  Pacific-Union  Pacific. 


Fig.  2374.   Cast  Iron  Bat- 
tery Chute.    Bryant 
Zinc  Company. 


Figs.  2388-2,392.     Wire   Tags. 


SECTION  OF  OUTSIOf  COVCR 

Figs.    2375-2382.      Details    of    Special    Battery    Chute. 
Northern  Pacific. 

Nalifleiibll  (Eytlttlt  to  bfnvdeofJ,  "stock 


Figs.    2383-2387.     Battery    Chute    and    Wiring.     Sunset 
Lines. 


Fig.  2393.     Wooden  Battery  Box.     Bryant  Zinc  Company. 


Figs.  2394-2399 


ACCESSORIES. 


343 


Fig.    2394.      "Ironcrete"   Bat-        Fig.  2395.   Cast  Iron  Bat- 
tery Chute.  Potter-Wins-        tery  Chute.   Railroad  Sup- 
low  Company.  ply   Company. 


ER9zii 

••Hi 


Fig.  2396.    Automatic  Battery 

Elevator.     Bryant  Zinc 

Company. 


BATTERY    ELEVATORS. 

Fig.  2396  shows  the  automatic  elevator  for  battery  chutes 
made  by  the  Bryant  Zinc  Co.  It  consists  of  a  regular  elevator, 
to  which  have  been  added  three  metal  rods.  These  rods  are 
fastened  at  the  lower  end  in  a  wooden  disc,  which  is  the  same 
size  as  the  elevator.  The  rods  pass  through  holes  near  the 
outer  edge  of  the  different  shelves  of  the  elevator.  When  the 
elevator  is  pulled  up  out  of  the  chute,  the  bottom  disc  drops 
down  until  it  is  20  inches  below  the  bottom  of  the  elevator 
proper.  When  the  bottom  of  the  elevator  reaches  the  top  of 
the  chute,  a  locking  dog  automatically  extends  out  over  the 
side  of  the  chute.  The  elevator  will  now  rest  on  this 
locking  dog. 

The  three  rods  extending  downward  into  the  chute  to  the 
lower  disc  will  support  the  elevator  in  an  upright  position, 
while  batteries  are  being  changed  or  renewed.  When  it  is 
desired  to  lower  the  elevator,  it  is  only  necessary  to  give 
it  a  slight  twisting  motion,  which  will  unlock  the  supporting 
device  and  allow  the  elevator  to  be  lowered  to  bottom  of 
chute. 

Other  forms  of  battery  elevator  are  shown  in  Figs.  2370- 
2';71,  2397-2399,  and  2366,  the  latter  shewing  a  form  of  wir- 
ing used  by  the  Atchison,  Topeka  &  Santa  Fe. 


BATTERY    CHUTES. 

Figs.  2397-2399  show  battery  chutes  made  by  the  C.  F. 
Massey  Co.  These  are  7  ft.  long  and  10  in.  inside  diameter. 
They  are  cast  in  one  piece  from  waterproof  cement  reinforced 
by  a  steel  cage,  and  are  provided  at  the  top  with  a  cast  iron 
ring  to  which  the  cover  is  attached.  The  weight  of  the  chute 
is  485  Ibs.  Nine-foot  chutes  of  similar  construction  weigh 
525  Ibs. 

Fig.  2395  shows  a  cast  iron  battery  chute  to  which  is  attached 
a  trunking  cap.  The  figure  shows  also  how  the  trunking  is  fitted 
into  the  cap.  In  Fig.  2394  a  reinforced  concrete  chute  is 
shown  with  a  trunking  cap.  Figs.  2397-2399  show  provisions 
for  three  forms  of  attaching  the  trunking  or  conduit  carrying 
the  wiring  to  the  chute. 


Figs.  2397-2399.     Cement  Battery  Chutes.     C.  F.  Massey  Company. 


344 


ACCESSORIES. 


Figs.  2400-2406 


T 

1      J 

*i 

j 

tVh 

J          J 

.?> 

K 

^ 

J.JC. 

J          J 

Co/?c/-e/e. 
/     C«e/T7e/7r  v-i^'*>-»-j^vjj  ,~.j 

^  ^/TO'.   — j         ---H^r^^ay L_ 

3  Sfone  ^ 6LO"- _^ 


Figs.  2401-2404.     Brick  Battery  Well.     New  York  Cen- 
tral &  Hudson  River. 


Fig.  2400.     Reinforced  Concrete     Battery  Well.     C.  F. 
Massey  Company. 


Figs.   2405-2406.     Reinforced   Concrete  Battery  Vaults.     Pottcr-Winslow  Company. 


Figs.  2407-2415 


ACCESSORIES. 


345 


GROUND 


PLAN 


3-6 


in.  Boiler  Plate  Cover 


SECTION 

Figs.  2407-2409.     Standard  Concrete  Battery   Well.     New   York,    Ontario   &  Western. 


H 


Fig.  2412.    Relay  Box.  Rail- 
road Supply  Company. 


Figs.  2410-2411.     Battery  House.     Michigan   Central. 


Door,  Open. 


tenti/crfing 
Hole.. 


ft" 

$P 


Figs.    2413-2414.      Wooden    Battery    Cellar.      Chicago    & 
North-Western. 


Fig.    2415.       Battery    Cupboard. 
Michigan  Central. 


346 


ACCESSORIES. 


Figs.  2416-2424 


CIRCUIT  CONTROLLERS 


SWITCH  BOXES 


HALL   STYLE  "G"   SWITCH  BOX. 

Fig.  2416  shows  the  Style  "G"  Switch  Box  made  by  the  Hall 
Signal  Co.  The  contacts  of  this  instrument  are  so  arranged 
as  to  be  used  normally  open  or  normally  closed,  or  any  com- 
bination of  contacts  may  be  obtained  by  a  proper  connection 
of  circuits. 


Fig.  2416.     Hall  Style  "G"  Switch   Box. 

Each  spring  is  provided  with  a  front  and  back  connection, 
with  separate  binding  posts,  and  is  forced  mechanically  in 
one  direction. 


Fig.  2417.     Style  "G"  Switch  Box  Complete. 


Fig.  2418.     Hall   Style  "G"  Switch   Box  with  Side   Cut 
Away  to  Show  Contacts. 

The  operation  of  the  contacts  is  accomplished  by  segments 
which  are  independently  adjustable,  the  adjustment  being  per- 
manent when  made,  as  the  operating  arms  are  locked  on  the 


shaft  by  a  worm  gear  arrangement  which  prevents  slipping, 
and  requires  the  turning  of  a  bolt  by  screw  driver. or  wrench 
in  order  to  change  the  adjustment. 

If  a  contact  is  used  as  a  shunt  the  connections  to  binding 
posts  are  made  in  such  a  manner  that  the  contact  is  mechan- 
ically forced  closed  by  the  movement  of  the  switch  point  one- 
eighth  in.,  and  is  held  mechanically  in  that  position  until 
the  switch  is  returned  to  its  normal  position. 

If  a  contact  is  used  for  opening  a  line  circuit,  the  con- 
nections to  the  binding  posts  are  so  made  that  the  contact  is 


Figs.    2419-2420.      Showing    Method    of    Adjusting    Hall 
Style  "G"  Switch  Box. 


mechanically  forced  open  by  the  first  movement  of  the  switch, 
and  held  open  mechanically  until  the  switch  is  returned  to 
its  normal  position.  There  is  no  dependence  on  the  operation 
of  any  spring  for  the  display  of  a  danger  signal,  and  it  is 
impossible  for  a  fused  contact  to  hold  a  circuit  closed. 

The    binding  posts    extend    through   one    end    of   the    case   in 
such  a  manner  that  the   wire  cpnnections  are  made  in   a  sep- 


\m 


JUT 


Figs.  2421-2422.    Hall  Insulated  Ro,d  With  Switch  Lugs 
for   Style   "G"   Switch   Box. 


Figs.  2423-2424.     Plain  Rod  With  Switch  Lugs  for  Style 
"G"  Switch  Box. 

urate    compartment    from    that  .  containing    the    contacts    and 
moving  parts  of  the  apparatus. 
That   portion   of   the  cover   which   protects   the  contacts   and 


Figs.  2425-2428 


ACCESSORIES. 


347 


movable  parts  of  the  Instrument  is  fitted  with  a  tubular  rubber  cover    may    be    closed    sufficiently    tight    to    exclude    dust    and 

gasket    which    is    securely   fastened    in    a    groove    which    is    pro-  water.      This   switch  box  stands  six   and   three-quarter   in.   high 

vided  for  that   purpose.  over    all,    and    is    so    arranged    that    it    may    be    changed    from 

The  hasp  is  attached  to  a  threaded  nut  by  which  means  the  left-hand  to  right-hand  or  vice  versa. 


Figs.  2425-2426.     Style  "E"  Switch  Box. 


Names   of   Parts   of  the  Hall  Style   "C"   Switch   Box 
Figs.  2427-2428. 


A  Switch  Point  Lug 

B  Screw  Jaw 

C  Lignum   Vitae  Roller 

D  Contact  Spring,  with  Platinum  Contact 

E  Spring  Anvil,  with  Platinum  Contact 

F  Heel  of  Contact  Spring 


Figs.  2427-2428.     Style  "C"  Switch  Box.     Hall   Signal  Company. 


348 


ACCESSORIES. 


Figs.  2429-2432 


UNION  ELECTRIC  SELECTOR. 

The  selector  shown  In  Fig.  2429,  is  for  controlling  four  cir- 
cuits in  either  extreme  position  and  can  be  worked  directly 
from  switch  points  or  from  the  slide  bar  of  a  switch  and  lock 


SECTIONAL      SIDE      VIEW 


Fig.  2429.     Electric   Selector  for   Four   Circuits   in   Each 

Direction,  Operated  by  Switch   Points  and  by 

Switch  and   Lock  Movements.     Union 

Switch    &    Signal    Company. 


SECTIONAL       SIDE     VIEW 


Fig.  2430.     Electric  Selector  for  Six  Circuits   in  Each 
Direction,  Operated  Same  as  Fig.  2439. 

movement.  When  operated  directly  from  the  switch  points  it 
can  be  adjusted  to  open  when  point  has  moved  %  in.,  and  when 
operated  from  slide  bar  of  a  switch  and  lock  movement  it  can 
be  adjusted  so  that  there  is  at  least  a  half-inch  wipe  or  slide 
on  the  springs  before  the  circuit  is  broken. 


The  contact  carriers  are  adjustable  for  variable  throws  of 
switches  and  the  operating  arm  can  be  turned  up  or  down  and 
placed  on  either  side  of  the  box  to  suit  conditions. 

The  selector  shown  in  Fig.  2430,  controls  six  circuits  in  either 
extreme  position.  It  is  similar  in  all  respects  to  Fig.  2429. 


UNION    UNIVERSAL    SWITCH    CIRCUIT   CONTROLLER. 

The  switch  circuit  controllers  illustrated  in  Figs.  2431  and 
2432  are  universal  in  that  the  same  box  and  fittings  are 
used  for  either  two  or  three  position  work,  the  only  difference 
between  the  controllers  being  in  the  number  and  style  of  cams 


SECTIONAL    SIDE   VIEW 


Fig.  2431.     Universal  Switch  Circuit  Controller.    Union 
Switch  &  Signal  Company. 


IE)        -i  ii 


SECTIONAL    SIDE    VIE/ 


Fig.  2432.     Universal  Switch  Circuit  Controller.    Union 
Switch  &  Signal  Company. 

used,   and   the  two-position    having   one   and   the    three-position  -. 
two  adjustable  cams  per  set  of  contacts. 

The  operating  arms  and  arms  for  carrying  the  cams  are 
mounted  upon  a  square  shaft.  The  controller  can  be  placed  on 
either  side  of  the  track  and  have  the  cover  open  away  from 


Figs.  2433-2437 


ACCESSORIES. 


349 


the  rails ;  is  six  and  three-quarter  in.  high  and  is  designed  for 
application  to  any  switch  having  not  more  than  five  and  one- 
half  in.  throw. 

The  two-position  controller  can  be  equipped  with  either  front 
or  back  contacts,  and  is  adapted  for  shunting  track  circuits. 
The  three-position  controller  can  be  equipped  with  front  and 
back  contacts  and  double  adjustable  cams,  giving  it  a  selective 
feature.  Contacts  in  both  the  two  and  three  position  controllers 
are  positively  forced  open  or  closed  by  the  cams. 

The  contacts  and  operating  mechanism  are  placed  in  a  dust 
and  dirt  proof  compartment  separate  from  the  terminal  com- 
partment, keeping  all  wearing  parts  free  from  dirt. 

The  contact  springs  and  operating  levers  are  mounted  upon 
the  same  bakelite  terminal  block,  thus  allowing  all  parts  to  be 
removed  from  the  box  without  disturbing  the  adjustment.  The 
terminal  block  is  a  moisture  and  heat  proof  insulation  of  great 
mechanical  strength  and  its  use  eliminates  the  insulation  be- 
tween the  block  and  contact  springs  and  between  the  terminal 
block  and  terminal  posts. 

All  contacts  are  in  plain  view,  ef.sily  accessible  and  each 
spring  can  be  separately  removed.  Standard  14-24  binding 
posts  are  used. 

The  wires  are  brought  into  the  terminal  compartment  through 
trunking  and  protected  at  the  top  by  a  cast  iron  hood. 

A  centering  device  to  return  the  operating  arm  to  a  central 
position  in  case  of  a  broken  or  disconnected  operating  rod  may 
be  added  if  desired. 


Figs.  2436-2437  show  a  switchbox  made  by  the  General  Railway 
Signal  Company  and  used  on  the  Electric  Zone  of  the  New  York 
Central  &  Hudson  River.  It  is  provided  with  three  normal  and 
three  reverse  contacts,  the  six  springs  on  each  side  constituting 
three  pairs,  each  pair  being  bridged  by  a  brass  contact  plate. 
These  plates  are  carried  by  hard  rubber  blocks  attached  to  the 
top  of  the  contact  arm.  The  lower  part  of  the  contact  arm  is 
formed  into  a  jaw  at  one  end,  and  those  jaws  are  engaged  by 
the  operating  arms,  which  are  adjustable.  The  adjusting  arm 
A  is  rigidly  attached  to  the  shaft,  which  is  moved  by  the  ope- 
rating lever. 

When   the   switch    is    normal,   the  parts   assume    the   position 


Fig. 


/  //  s&x/3/4  "Under  Head 

V'-l'v 


2435-     Vertical  Rotary  Switchbox,  Figs.  2433-2434. 
Operated  by  Switch  and   Lock  Movement. 
Pennsylvania   Railroad. 


Names    of    Parts     of    Switchbox. 
Figs.  2436-2437. 

A  Adjusting  Arm 

B  Right-Hand  Operating  Arm 

C  Right-Hand  Contact  Arm 

D  Right-Hand  Contact  Spring 

E  Left-Hand  Operating  Arm 

F  Left-Hand  Contact  Arm 

G  Left-Hand  Contact  Spring 

H  Left-Hand  Contact  Spring 

K  Right-Hand  Spiral  Spring 


Figs.  2433-2434.     Vertical   Rotary  Switchbox,  Model  2. 
The  Union  Switch  &  Signal  Company. 

Figs.  2433-2435  show  the  vertical  rotary  switchbox,  Model  2, 
made  by  The  Union  Switch  &  Signal  Company,  a  style  generally 
used  in  automatic  block  signaling.  The  box  is  usually  fixed 
to  a  tie,  about  3  ft.  from  the  track.  The  movement  of  the  switch 
points  closes  contacts  in  the  box  which  connect  the  opposite 
rails  of  the  track,  so  as  to  de-energize  the  track  relay,  and  thus 
throw  to  the  stop  position  the  home  signal  for  that  section,  as 
in  Fig.  475.  Contacts  may  also  be  arranged  to  break  the  control 
circuits  for  signals  when  the  switch  Is  open.  The  driving  or 
connecting  rod  is  fastened  to  the  switch  rail  by  a  lug  bolted 
close  to  the  point  on  the  normally  closed  side.  Adjustment  is 
provided  so  that  the  opening  of  the  switch  point,  as  much  as 
V-i  in.,  will  operate  the  circuit  controllers  in  the  box.  The  wires 
are  brought  into  the  box  through  a  hole  in  the  tie  to  binding 
posts  connected  with  the  contact  springs  which  are  guided  by  a 
crossplece.  The  crosspiece  is  operated  to  move  the  springs  by 
a  roller  engaging  a  cam  revolved  by  a  shaft.  The  shaft  is  turned 
by  a  crank  driven  by  the  connecting  rod.  There  is  a  large  lug 
on  the  bottom  of  the  case  which  is  set  into  the  tie  as  shown, 
holding  the  box  in  place. 


Figs.  2436-2437.     Sectional  View  of  G.  R.  S.  Switchbox. 


35° 


ACCESSORIES. 


Figs.  2438-2444 


shown  in  Fig.  2436.  The  operating  arm  B  engages  the  jaw  of 
the  contact  arm  C,  forcing  it  downward  and  drawing  up  the 
contact  plates  against  the  springs  D,  bending  them  upward. 
This  holds  the  three  normal  contacts  closed.  As  the  switch 
starts  to  move  to  Its  reverse  position,  B  is  raised  and  the  spiral 
spring  K  forces  C  away  from  the  contact  springs.  However,  if 
the  spiral  spring  should  be  broken  the  operating  arm  B  would 
accomplish  the  same  result  before  disengaging  with  the  jaw. 


G.   R.    S.    UNIVERSAL   SWITCH  BOX. 

The  Model  5  Form  A  switch  box  (Fig.  2440),  which  is  made 
by  the  General  Railway  Signal  Co.,  can  be  used  for  shunting  or 
breaking  track  circuits,  for  opening  line  circuits  or  for  select- 
ing circuits. 

Contacts,  of  which  there  are  four  normal  and  four  reverse, 
are  designed  to  control  voltages  up  to  and  including  220.  By 
the  use  of  supplemental  cover,  contacts  are  protected  from 
frost  and  condensation,  and,  when  main  cover  is  open,  from 


Fig.    2438.     Switchbox,   with    Cover   Open. 


Fig.   2439.     Switchbox   and   Selector. 


Fig.  2441. 


Fig.  2443. 


Fig.   2440.     Model    5,    Form   A,    Shunt 

Switch  Box.     General  Railway 

Signal  Company. 


Figs.  2441-2444.    High  Voltage  Switch 

Boxes.     General  Railway  Signal 

Company. 


Fig.  2444. 


Fig.  2442. 


When  the  operating  lever  is  in  the  center  of  its  stroke,  neither 
jaw  is  engaged  and  all  contacts  are  open.  In  the  last  %  in.  of 
its  stroke,  the  operating  lever  brings  the  operating  arm  E  into 
engagement  with  F,  closing  the  reverse  contacts  G,  in  the  same 
manner  as  were  D  in  the  extreme  normal  position. 

It  will  be  seen  from  the  above  that  this  switchbox  is  designed 
for  use  where  control  circuits  are  broken  and  is  not  desirable 
where  track  circuits  are  to  be  shunted.  The  switch  shown  in 
Figs.  1! 4 59-2461  is  designed  for  shunting  purposes. 


rain  ;  contacts  are  all  mounted  on  one  panel  of  slate  which 
is  removable  without  interfering  with  contact  adjustment; 
contacts  are  forced  open  and  forced  closed,  spring  action  only 
not  being  relied  upon. 

The  operating  crank  has  a  maximum  throw  of  six  Inches, 
and  may  be  placed  on  either  side  of  box.  The  height  of  the 
box  is  six  inches.  A  centering  mechanism  which  will  auto- 
matically open  all  the  circuits  if  operating  rods  become  dis- 
connected can  be  provided. 


Figs.  2445-2450 


ACCESSORIES. 


If 


O 


O 


Figs.   2445-2446.     Switchbox. 


o 

ID 


ED 

O 


Pigs.  2445-2446  show  a  switchbox  in  which  are  mounted  con- 
tacts 3,  3-A,  4,  4-A,  5,  5-A,  6  and  6-A,  which  are  closed  by  the 
insulated  rollers  7  and  8,  carried  by  toggle  pin  9.  The  toggle 
is  composed  of  link  10  and  tumbler  11,  which  hangs  on  pin  9 
The  tumbler  11  rotates  on  stationary  spindle  12,  and  is  actuated 
by  the  slide  17.  The  upper  end  of  link  10  engages  with  the 
concave  portion  of  yoke  14,  which  is  forced  down  against  the 
upper  end  of  toggle  "10  by  helical  springs  15  and  15-A.  The 
tongue  13  is  attached  to  vertical  spindle  16  and  engages  with 
and  moves  slide  17  in  guide  18  and  18-A.  This  slide  engages 
the  portion  of  tumbler  11,  which  is  below  spindle  12,  and  as 
slide  17  moves  either  to  right  or  left,  it  causes  tumbler  11  to 
swing  on  spindle  12  until  the  hinge  pin  9  reaches  a  point  on 
either  side  of  center.  After  reaching  this  point,  the  springs  l-o 
and  15-A  force  the  yoke  14  down,  causing  the  toggle  to  close 
contacts  on  the  side  to  which  it  swings.  The  vertical  spindle 
16  extends  through  the  bottom  of  case  1  and  attached  to  it  's 
crank  arm  39.  This  arm  is  operated  to  left  or  right  by  the 
switch  point. 

The  circuit  to  be  opened  is  broken  during  the  first  3  deg.  of 
movement  of  the  crank  19,  and  the  circuit  to  he  closed  is  made 
up  during  the  last  3  deg.  of  movement  of  the  crank.  During 
the  intermediate  movement  of  the  crank,  the  contacts  remain  in 
the  portion  shown.  Other  arrangements  of  contacts  can  be 
made  ;  contacts  may  be  made  up  during  the  first  3  deg.  of  move- 
ment of  crank  and  othersr  remain  closed  until  the  last  3  deg. 
of  movement  of  crank  19. 


Names   of   Parts  of   Switchbox;  Figs.   2445-2446. 

1  Case  13  Tongue 

2  Cover  14  Yoke 

3-6a  Contact  Springs  15-15^  Helical  Springs 

7-8  Insulated  Rollers  16  Vertical  Spindle 

9  Toggle  Pin  17  Slide 

10  Toggle  Link  i8-i8a  Guide  S 

11  Tumbler  19  Crank  Arm 

12  Horizontal  Spindle  20-200  Openings  for  Wires 


Fig.  2449.     Model  "B"  Switch  Box. 

American  Railway  Signal 

Company. 


Figs.  2447-2448.     Model  "B"  Switch   Box.     American 
Railway  Signal  Company. 


Fig.    2450.     Model   "B"    Switch    Box 

Open.     American    Railway 

Signal  Company. 


352 


ACCESSORIES. 


Figs.  2451-2456 


Figs.  2452-2453.     Plan  and  Section  of  Switchbox 
Fig.  2451. 


Fig.   2451.      Switchbox.     American    Railway   Signal 
Company. 


Figs.  2454-2456.     Switchbox.     Railroad  Supply  Company. 


Figs.  2457-2462 


ACCESSORIES. 


353 


Figs.  2457-2458.     Switchbox.     Railroad   Supply 
Company. 


000000 

oooooo 


Figs.  2459-2461.     Shunt  Switchbox,  with  Front  and  Back  Contacts. 
General  Railway  Signal  Company. 


Names  of  Parts,  Electrical  Point  Detector;  Fig.  2462. 


A  Lug 

B  Switch  Point 

C  Stock  Rail 

D  Case 


F     Crank  Arm 
G    Contact  Arm  and  Shaft 
H  H1  Contact  Springs 
JJ1  Contact  Plates 


E     Operating  Rod        K  K1  Adjustable  Contact  Points 


Fig.  2462.     Electr.'c   Point  Detector    (Switch- 
box).     W.  R.  Sykes'  Interlocking  Com- 
pany, Ltd.,  of  England. 


354 


ACCESSORIES. 


Figs.  2463-2474 


SIGNAL  CIRCUIT  CONTROLLERS. 


TMOX    ROTARY    CIRCUIT    CONTROLLER. 

This  circuit  controller  is  designed  for  application  to  the  rear 
end  of  the  semaphore  shafts  of  mechanical  signals.  It  has  two 
contact  springs,  which  control  two  independent  circuits.  These 
springs  are  actuated  by  two  cams  connected  to  the  semaphore 
shaft  by  a  bolt  and  sleeve.  The  cams  have  corrugated  faces, 
making  it  possible  to  fasten  them  at  any  desired  angle,  so  as 
to  operate  the  contact  springs  at  whatever  point  in  the  stroke 
of  the  signal  may  be  necessary. 


Figs.  2464-2465.     Combined  Motion  Plate  Pole  Changer 
and  Circ.uit  Controller  for  Electro-Pneu- 
matic   Dwarf   Slide    Signal. 


Figs.  2466-2467.     Combined  Motion  Plate  Pole  Changer 
and  Circuit  Controller  for  Electro- 
Pneumatic  Slide  Signal. 


Fig.    2463.      Duplex    Rotary    Circuit    Controller.      The 
Union  Switch  &  Signal  Company. 


For  Circuit  Controller,  Closing  Two  Circuits  at  Clear  and  one 
at    Stop. 


For    Circuit   Controller,    Closing    One    Circuit    at    Clear    and 
Two  at  Stop. 


For  Combined  Pole  Changer  and  Circuit  Controller,  Opening 

Circuit    When    Starting    to    Clear    and    Operating 

Pole  Changer  at  Clear. 


For  Combined  Pole  Changer  and  Circuit  Controller  for  Three 
Position  Signal,  Opening  Circuit  When  Starting  to  Clear. 


For  Combined  Pole  Cha-nger  and  Circuit  Controller,  Operating 
Both  When  Starting  to  Clear. 

Figs.  2468-2469.     Combined  Motion  Plate  Pole  Changer       Figs.   2470-2474.     Circuit    Controller   Plates   for  Use  with 
and    Circuit  Controller  for   Electro-  Electro-Pneumatic  Signals.     The  Union  Switch 

Pneumatic  Signal.  &  Signal  Company. 


Figs.  2475-2478 


ACCESSORIES. 


355 


Fig.  2475.     Four- Way  Circuit  Controller  for  Attaching 

to  Shaft  of  Mechanical   Signals.     Union 

Switch  &  Signal  Company. 


Fig.  2476.     Style  "E"  Commutator  Applied  to  Mechan- 
ical   Signal.      Hall    Signal    Company. 


Fig.    2477.      Style   "E"    Commutator,    Four-Way.      Hall       Fig.  2478.     Style  "E"  Commutator  Six-Way.     Hall  Sig- 
Signal  Company.  nal  Company. 


356 


ACCESSORIES. 


Figs.  2479-2488 


Fig.  2479.     Circuit  Controller  for  Sig 
nals,  Levers,  etc.     General  Rail- 
way Signal  Company. 


Figs.  2480-2481.    Circuit  Controller, 
Roller  Type  for  Signals,  Lev- 
ers, etc.     General  Railway 
Signal    Company. 


Fig.  2484.    Circuit  Controller  for  Signals, 

Levers,  etc.     Railroad  Supply 

Company. 


Fig.    2485.      Circuit    Controller,     Fig. 
2484  with  Cover  Removed.  Show- 
ing Contact  Springs  Mounted,, 
on  Slate  Block. 


Figs.  2482-2483.    Circuit  Con- 
troller    for     Electro-Pneu- 
matic Signals.     The  Un- 
ion Switch  &  Signal 
Company. 


Names  of  Parts,  Hall  Track 

Instrument;  Figs.  2487- 

2488. 

i,  2     Terminal  Screws 
A     Stringing  Ann 
B     Contact  Spring 
C    Anvil 
D     Air  Chamber 
E     Chamber  in  Base 
F    Dust  Guard  and  Spring 
G    Large  Rubber  Spring 
H     Small  Rubber  Spring 
L    Lever 
R     Valve 

S    Piston  and  Rod 
X    Air  Passage 
Y    Pon 


TRACK,  TOWER  AND  BRIDGE  CIRCUIT  CONTROLLERS 


Fig.  2486.     Sectional  View  of  Figs.  2484-2485,  Showing 
Operation  of  Parts. 

HALL,    TRACK    INSTRUMENT. 

Figs.  2487-2488  show  the  track  instrument  made  by  the  Hall 
Signal  Company.  Depression  of  lever  L  by  the  wheels  of  a  train 
forces  piston  S  upward.  This  piston  moves  in  an  air  chamber  D, 
and  communicates  motion  to  the  swinging  arm  A  of  the  circuit 
controlling  apparatus. 

Upper  and  lower  ends  of  the  air  chamber  D  are  connected 
with  each  other  by  an  air  passage  X,  and  valve  R,  so  arranged 


Figs.  2487-2488.     Track  Instrument.     Hall  Signal 
Company. 

that  when  piston  S  is  forced  upward,  a  portion  of  the  air 
above  the  piston  is  forced  out  through  the  port  Y  through  valve 
It  and  passage  X,  to  the  under  side  of  the  piston.  Continued 
raising  of  the  piston  covers  opening  Y,  and  shuts  off  communica- 


Figs.  2489-2497 


ACCESSORIES. 


357 


tion  between  top  and  bottom  of  chamber  D.  The  air  remain- 
ing forms  a  cushion  preventing  the  piston  rod  from  being  thrown 
forcibly  up  against  the  cover.  The  beveled  top  of  the  piston  rod 
extends  through  the  plate  on  which  the  contacts  are  mounted 
and  when  raised  engages  the  roller  of  swinging  arm  A,  forcing 
spring  B  into  contact  with  its  anvil  C,  thereby  completing  a 
circuit.  Air  below  the  piston  also  acts  as  a  cushion  to  prevent 
shocks  when  the  piston  falls.  R  is  a  valve  for  regulating  the 
air  pressure.  Its  lower  extremity  covers  the  top  of  the  passage 
X.  G  and  H  are  rubber  springs  so  compressed  that  any  weight 
less  than  that  imposed  by  the  pressure  of  an  ordinary  car  wheel 
fails  to  operate  the  piston.  Contact  springs  can  be  arranged 
either  normally  open  as  shown,  or  normally  closed,  and  they 
can  be  furnished  in  multiple  for  the  control  of  a  number  of 
circuits. 


FOULING    BAR. 


The  fouling  bar,  illustrated  in  Fig.  2489,  is  used  to  operate  a 
circuit  controller,  thereby  locking  a  switch  or  signal  until  the 
train  is  off  the  bar  and  clear  of  a  certain  section  of  track. 


Fig.   2489.     Fouling   Bar.     Great   Western   Railway  ot 
England. 


Fig.  2490-2491.    Table  Circuit  Controller.    Union  Switch 
&  Signal  Company. 


Fig.  2492.     Hand  Circuit  Controller,  Cover 
Removed.    The  Union  Switch  & 
Signal  Company. 


Figs.  2493-2497.     Magnetic  Circuit  Controller,  With  and  Without  Bell.     The  Union  Switch  &  Signal  Company. 


358 


ACCESSORIES. 


Figs.  2498-2506 


Fig.  2498.     Floor  Push.     Railroad 
Supply  Company. 


Fig.  2499.  Double 
Circuit  Controller 
for  Use  with  Me- 
chanical Interlock- 
ing Machines.  Un- 
ion Switch  &  Signal 
Company. 


Figs.    2500-2501.     Floor    Push.      General    Railway 
Signal    Company. 


G.     R.     S.     FLOOR    I'USH. 

In  the  floor  push  shown  in  Figs.  2500-2501  the  circuit 
is  closed  by  pushing  down  on  the  plunger  B  ;  this  com- 
presses spring  E.  and  brings  contact  ring  H  against 
springs  K.  Ring  H  is  mounted  in  an  insulating  bush- 
ing held  in  place  on  rod  G  by  the  nut  L.  Shield  D  is 
fastened  to  rod  G,  and  diverts  all  water  and  dirt  that 
may  enter  from  above  to  the  cavity  in  F,  thus  keeping 
the  contacts  clean  and  free  from  corroding  influences. 


Figs.  2502-2503. 


Names  of  Parts  of  Floor  Push;  Figs.  2499-2500. 


Weatherproof  Floor   Push. 
Supply   Company. 


Railroad 


Floor  Socket 

Plunger 

i"  Wrought  Iron  Pipe 

Shield 

Spring 

Contact  Box 

Steel  Rod 

Contact  Ring 

Contact  Spring 

Brass  Nut 

Cap 

Binding  Post 


2504.     Double  Pole  Single 
Throw  Knife  Switch, 
Porcelain  Rase: 


Fig.  2505.     Table  Push.     The  Union 
Switch    &    Signal    Company. 


Fig.  2506.  Single  Cir- 
cuit Controller  for  Use 
with  Mechanical  Inter- 
locking Machine.  The 
Union  Switch  &  Signal 
Company. 


Figs.  2507-2514 


ACCESSORIES. 


359 


FLOOR    PUSH. 

The  Hall  floor  push  is  shown  in  Fig.  2507.  The  circuit  is 
closed  by  pressing  on  plunger  P,  the  movement  of  which  com- 
presses spring  S,  forcing  circular  contact  C  against  spring  D. 


Fig.    2508.     Double    Pole    Single    Throw    Knife    Switch 
with   Cartridge   Fuse   Protection,   Slate   Base. 


Fig.  2510.     Double  Pole  Sin- 
gle  Throw   Knife  Switch 
Porcelain  Base.  Rail- 
road Supply  Com- 
pany. 


Fig.    2509.      Two-Point 

Switch,  Slate  Base. 

Railroad     Supply 

Company. 


Fig.    2511.      Cam    Circuit    Controller. 

The,  Union  Switch  &  Signal 

Company. 


Fig.  2507.     Floor  Push  Complete.     Hall  Signal 
Company. 


When  the  pressure  is  removed,  plunger  P,  by  action  of  spring 
S,  rises  to  its  normal  position.  The  projecting  head  of  the 
plunger  and  the  provision  for  drainage  at  bushing  M  prevent 
the  access  of  dirt  and  water. 


Fig.   2513.      Bell    Key   in    Case.      The 
Union  Switch  &  Signal  Company. 


Fig.    2512.      Two-Point 
Switch,  Hard  Rub- 
ber Base. 


Fig.    2514.     Bell    Key,    Fig.    2513. 


360 


ACCESSORIES. 


Figs.  2524-2530 


Two   Contact   Strap   Key. 


Single    Contact   Strap    Key. 


Single  Point  Switch.  Two-Point  Switch. 

Figs.  2524-2527.     Switches.     United   Electric  Apparatus  Company. 


IRON     CLAD     SWITCH. 

This  switch  is  designed  for  use  in  connection  with  electric 
switch  locks  where  a  number  of  switches  are  controlled  from 
one  central  point.  It  is  arranged  so  that  only  one  electric  lock 
can  be  unlocked  at  a  time,  thus  preventing  more  than  one 
train  entering  the  main  track.  Made  with  from  two  to  six 
points.  Size :  five  inches  square,  three  inches  high. 


STRAP    KEY. 

Fig.  2530  illustrates  a  type  of  strap  key  manufactured  by 
the  Bryant  Zinc  Co.  This  key  has  heavy  binding  posts  and  is 
equipped  with  upper  and  lower  platinum  contacts,  It  is  so 
arranged  that  it  can  be  used  for  open  or  closed  .  circuit  or 
both.  An  adjustment  screw  regulates  the  travel  of  the  lever 


Figs.  2528-2529. 


Iron  Clad  Switch. 
Company. 


Bryant  Zinc 


Fig.   2530.     Strap    Key.     Bryant    Zinc    Company. 


Figs.  2531-2541 


ACCESSORIES. 


361 


Fig.  2531.     Two-Point  Switch. 


Fig.  2532.     Track  Instrument.     Railroad  Supply  Company. 


Fig.  2533.     Sectional  View 
of  Fig.  2534.     Show- 
ing  Operation 
of  Key. 


Fig.  2534.     Push  Key.     Rail- 
road Supply  Company. 


Figs.  2535-2536.     Strap  Key.     Railroad  Supply  Company. 


Fig.  2537.     Six- Way  Bridge  Cir- 
cuit   Controller.     Ameri- 
can Railway  Signal 
Company. 


Fig.  2539.     Elevation  of  Front  and   Side  of  Bridge 
Member.     T.   George   Stiles   Company. 


Fig.  2538.     Plan  View  of  Style  "C"  Drawbridge  Circuit 
Controller.    T.  George  Stiles  Company. 


Fig.  2540.     Front  Elevation  of  Abutment  Member.     T.      Fig.   2541.     Side   View   of   Circuit   Controller   Coupled. 
George  Stiles  Company.  T.  George   Stiles   Company. 


362 


ACCESSORIES. 


Figs.  2542-2549 


Fig.  2542.     Drawbridge  Circuit  Closer  (24-Way)  Svith  Cen- 
tering  Device.     Slide  Withdrawn. 


Fig.    2543.     Drawbridge    Circuit    Closer     (24-Way)     with 
Centering  Device.     Contacts  Closed. 


Fig.  2544.    Drawbridge  Circuit  Closed  (12- Way)  with  Cen- 
tering Device.     Contacts   Closed. 


Fig.  2546.     Drawbridge   Circuit   Controller   with  Cover 
Removed.     Hall   Signal    Company. 


Fig.     2545.     Drawbridge     Circuit     Closer     (12- Way)     with 
Centering  Device.     Slide   Withdrawn. 


Drawbridge    Circuit    Controller    Covered. 
Hall  Signal  Company. 


Figs.    2542-2545    show    Drawbridge    Circuit    Controllers 

Made  by  the  General  Railway  Signal 

Company. 


Figs.  2548-2549.     Electric  Bridge  Coupler.     The  Union  Switch  &  Signal  Company. 


Figs.  2550-2555 


ACCESSORIES. 


363 


INDICATORS 


ANNUNCIATORS  AND  TOWER  INDICATORS 


Fig.    2550.      Group    of    Annunciators    and    Semaphore 
Indicators.     Union    Switch   &  Signal  Company. 


Fig.    2551.     Drop    Annun- 
ciator.    Railroad  Sup- 
ply Company. 


Fig.  2552.     Drop  Annunciator.     United   Flectric  Apparatus   Company. 


Figs.   2553-2554.     Open   and    Enclosed 
Types  Tower  Bells.      United  Elec- 
tric Apparatus    Company. 


F~ig.  2555.     Annunciator  with  Pulley  Attachment  for  Resetting. 
United    Electric    Apparatus    Company. 


364 


ACCESSORIES. 


Figs.  2556-2563 


5 

t' 

J 

J 

j 

i 

( 

H] 

«fll'K- 


Fig.  2556.     Installation  with   Open  Circuit  Relays  and   Open  Circuit 

Annunciators. 


Fig.  2557.  Circuits  for  Drop  An- 
nunciator, with  Interlocking  Relay 
on  Single  Track;  Automatically  An- 
nounces Trains,  in  One  Direction 
Only;  Normally  Closed  Track  Cir- 
cuits. Railroad  Supply  Company. 


Fig.  2558.     Circuit  for  Drop  Annunciator  with  Interlocking  Relay  on 

Single  Track;  Automatically  Announces  Train  in  One  Direction 

Only;  Normally  Closed  Track  Circuits.     Union  Switch 

&  Signal  Company. 
/  Mi/e  more  or  /ess 


W/r/fe,-. 


T    Recf- 


Fig.     2559.      Simple     Circuit       for 
Track  Indicator. 


/rrfarfocfringr 


ffefurrr /far/7-' 

Fig.   2560.     Circuit   for   Drop  Annunciator   for   Use   on      Fig.  2561.     Circuits  for  Block  Indicator  and   Signal  at 
Single  Track;  Automatically  Announces  Trains  Interlocking  Plant.     Boston  Elevated  Railroad. 

in  One  Direction  Only;  Normally 
Open  Track  Circuits. 


Figs.  2562-2563.     Iron  Case  Drop  Annunciator.     Union  Switch  &  Signal  Company. 


Figs.  2564-2571 


ACCESSORIES. 


365 


Figs.   2564-2565. 


Everett  Annunciator, 
ply    Company. 


Railroad    Sup- 


The  train  annunciator  shown  in  Fig.  2571  is  made  by  the 
Bryant  Zinc  Co.  This  is  a  compact  instrument  of  the  unit 
type,  with  iron  cover.  The  size,  4  in.  by  4  in.  by  11  in.,  per- 
mits placing  between  tower  windows.  This  annunciator  is  de- 
signed to  be  used  where  it  is  desired  to  silence  the  bell  while 
the  train  is  still  in  the  tripping  section. 

The  feature  of  stopping  the  bell  or  buzzer  with  the  train 
in  the  tripping  circuit  obviates  the  danger  of  towermen  plugging 
the  annunciator  to  silence  the  bell  or  buzzer  when  there  is  a 
long  train  in  the  circuit.  To  silence  the  bell  it  is  only  neces- 
sary to  raise  the  banner  to  the  upper  position,  at  which  point 
it  will  remain  until  the  train  leaves  the  tripping  circuit,  when 
it  will  automatically  restore  itself  and  be  ready  for  the  next 
approaching  train. 

The  possibility  of  the  banner  being  released  by  vibration  has 
been  eliminated  by  means  of  a  simple  device  which  holds  the 
armature  under  the  banner  until  the  coil  is  energized,  at  which 
time  the  vibration  stop  does  not  affect  the  movement  of  the 
armature.  The  annunciators  are  furnished  with  either  a  me- 
chanical restoring  rod  or  an  electrical  resetting  coil,  by 
means  of  which  the  banner  can  be  reset  from  any  part  of  the 
tower  through  a  push  button. 

Platinum  to  platinum  contacts  are  furnished.  The  annuncia- 
tors are  mounted  on  a  polished  hardwood  base  and  are  pro- 
tected by  a  neat  enameled  iron  case.  The  standard  winding 
is  25  ohms. 


Fig.  2566.     Drop  Annunciator  Group.     Railroad  Supply 
Company. 


Figs.  2567-2568. 
Types  of  Elec- 
tric Bells  Used 
With  Annuncia- 
tors and  Indica- 
tors or  Separ- 
ately. 


Fig.     2569.     Mechanism     of     Drop 
Annunciator.      Railroad    Sup- 
ply Company. 


Fig.    2570.     Drop    Annunciator.      Bryant    Zinc    Company. 


Fig.  2571.     Train  Annunciator.  Bryant 
Zinc  Company. 


366 


ACCESSORIES. 


Figs.  2572-2576 


Fig.    2572.     Tower    Indicator    Semaphore    Type.      Hall 
Signal  Company. 


Figs.    2574-2575.     Style    "C"    Tower     Indicator.       Hall 
Signal    Company. 


Fig.   2573.     Tower   Indicator   Disc   Type.      Hall    Signal       Fig.    2576.     Indicator    Case    Three-Way.      Hall    Signat 
Company.  Company. 


Figs.  2577-2582 


ACCESSORIES. 


367 


2577.     A.  C.  Tower  Indicator.     The  Union  Switch 
&   Signal   Company. 


UNION     TOWER     INDICATOR. 

The  Union  tower  indicator  illustrated  in  Figs.  2577-2578  has 
form-wound  coils  and  makes  use  of  9-C  relay  parts  wherever 
possible.  The  parts  are  mounted  on  a  porcelain  base  in  the 


Fig.  2578.     D.  C.  Tower  Indicator.     The  Union  Switch 
&  Signal  Company. 


same  manner  as  in  the  relay.  The  flexible  connections  at  the 
rear  of  the  contact  springs  are  unusually  long  and  are  brought 
forward  to  porcelain  terminal  strip.  All  of  the  terminal  posts 
are  very  accessible.  When  the  cover  is  removed  all  of  the 
parts  are  in  plain  view  and  easy  of  inspection.  The  mechanism 
is  universal  in  that  it  may  be  operated  by  d.  c.  magnets  or  by 
the  a.  c.  jaw  type  magnet. 


Figs.    2579-2580.     Indicator    with    Cover.       Hall    Signal      Figs.     2581-2582.     Style     "C"     Disc     Tower     Indicator. 
Company.  Hall  Signal  Company. 


368 


ACCESSORIES. 


Figs.  2583-2586 


Fig.  2583.     Upper  Quadrant  Semaphore  Indicator  with 

"Out    of    Order"    Disc.     United    Electric 

Apparatus  Company. 


Fig.   2584. 
Case. 


Disc   Indicator   A.   C.   or   D.   C.   with   Iron 
United  Electric  Apparatus  Company. 


Fig.  2585.     Upper  Quadrant  Semaphore  Indicator  A.  C. 
or  D.  C.    United  Electric  Apparatus  Company. 


Fig.   2586.     Lower   Quadrant   Semaphore    Indicator. 
United  Electric  Apparatus   Company. 


Figs.  2587-2596 


ACCESSORIES. 


369 


Figs.  2587-2588.     Group  of  Indicators  in  Wooden  Case.     Railroad 
Supply  Company. 


Fig.  2589.     Style  "A"  Indicator  Mechan- 
ism.     Railroad    Supply    Company. 


Fig.    2590.     Semaphore    Indicator.      Bryant    Zinc    Com- 
pany. 


/    \ 


Figs.  2591-2592.     Alternating  Current  Semaphore  Indi- 
cator. 

BRYANT    ZINC    SEMAPHORE   INDICATORS. 

The  indicators  (Fig.  2590)  made  by  the  Bryant  Zinc  Co.  are 
furnished  in  oak  cases,  size  6  in.  x  7  in.,  and  are  designed  for 
use  in  interlocking  towers  and  .signal  stations.  They  can  be  sup- 
plied with  two  contacts,  either  front  or  back.  When  wound  to 
50  ohms  resistance,  they  will  operate  on  .03  ampere.  Either  a  60 
or  90  deg.  indication  can  be  used. 


Fig.   2593.     Style  "A"   Semaphore   Indicator.     Railroad 
Supply    Company. 


Fig.    2594.     Indicator    Group. 


Figs.  2595-2596.     Disk  Indicator.     Railroad  Supply 
Company. 


370 


ACCESSORIES. 


Figs.  2597-2603 


Fig.   2597.     D.    C.    Indicator    Group    (Style    "A"),   with 

Hand    Screw    Releases    and    Terminal     Board. 

r  i  r>   -i  c-       1  r* 

General  Railway  Signal  Company. 


2601.     Universal  D.  C.  Indicator  Group.     Model 
Form  "A."     General  Railway  Signal  Company. 


Fig.  2598.    Universal  D.  C.  Indicator  Model  9,  Form  "A" 
(4-way).      General    Railway    Signal    Company. 


Fig.  2602.     Installation  of  Model  9,  Form  "A."     Indica- 
tors.    Chicago   &  North-Western. 


Fig.  2599.     Universal   D.    C.   Disc  Indicator    Model    9, 

Form   "A"    (2-way).      General    Railway 

Signal   Company. 


Fig.    2600.      Universal    D.    C.    Indicator    Model    9, 
Form  "A"  (6- way).     General  Railway  Sig- 
nal Company. 


Fig.  2603.     Universal  Electric  Lock  for  Mechanical  Inter- 
lockers,    Model    5,    Form '  "A."      General    Rail- 
way Signal  Company. 


Figs.  2604-2606 


ACCESSORIES. 


G.     R.     S.     DIRECT     CURRENT     INDICATORS. 

Kitf.  2598  shows  the  Model  9  Form  "A"  tower  indicator,  which 
to  all  intents  and  purposes  is  a  Model  9  relay,  arranged  with 
an  indicating  device.  It  is  provided  with  a  light  sheet-iron 


The  device  is  also  put  out  in  the  form  of  a  switch  indicator, 
as  shown  in  Fig.  2636.  The  case  is  weatherproof,  the  back 
door  being  removable  and  secured  by  the  G.  R.  S.  standard 
cam  hasp. 


Fig.    2604.     Three-Position    Signal    Repeater. 
Signal  Company. 


Federal 


THREE-POSITION     SIGNAL     UKPKATER. 

The  three-position  signal  repeater,  shown  in  Fig.  2604,  con- 
sists of  two  magnets,  1-2,  and  their  armatures,  3-4.  These  arma- 
tures are  connected  with  levers  5  and  6,  which  move  the  minia- 
ture semaphore  7  to  the  clear  or  stop  position  by  striking  pin  8 
on  counterweight  9,  secured  to  shaft  10,  on  which  is  mounted 
the  semaphore'  arm  7.  Connected  to  armature  3-4  are  contact 
fingers  13-14.  Front  contacts  15  and  16,  and,  if  required,  back- 
contacts  17  are  provided.  Binding  posts  are  mounted  on  the 
Lack  of  the  frame  18.  A  cover  with  glass  front  is  placed  over 
the  mechanism.  The  operation  of  the  repeater  is  as  follows :  A 
circuit  controller  on  the  signal  closes  the  circuit  through  magnet 
when  the  signal  assumes  the  stop  position.  This  throws  minia- 
ture semaphore  arm  to  the  corresponding  stop  position  by  lever 
5  striking  pin  8.  When  the  signal  assumes  the  proceed  position, 
circuit  through  magnet  1  is  broken,  circuit  through  magnet  2  is 
closed  and  the  arm  is  moved  to  the  clear  position  by  lever  6. 
The  controller  on  the  signal  'is  so  arranged  that  when  the  signal 
arm  is  15  degrees  below  stop,  or  15  degrees  above  proceed  posi- 
tion, neither  magnet  1  nor  2  is  energized  and  the  arm  will  as- 
sume a  middle  position,  as  shown  in  the  figure,  owing  to  the 
counterweight  9  swinging  into  a  vertical  position.  The  back 
and  front  contacts  can  be  used  for  making  or  breaking  circuits. 

THE   TRAIN    DESCRIBER. 

The  train  describer  made  by  the  Union  Switch  &  Signal  Com- 
pany, shown  in  Figs.  2605-2606,  provides  16  indications  which 
may  describe  express  or  local  passenger,  freight,  light  engines 
and  other  classes  of  trains ;  and  give  directions  as  to  what 
route  they  are  to  take.  Also  indications  may  be  provided  to 
convey  other  information  such  as  "cancel,"  "repeat,"  etc.  They 
are  generally  operated  in  sets  consisting  of  one  transmitter  and 
one  receiver,  though  one  transmitter  may  operate  two  or  more 
receivers,  or  one  receiver  may  show  indications  from  two  or 
more  transmitters.  The  transmitter  is  a  make  and  break  circuit 
controller  driven  by  a  key-wound  spring,  which  is  released  to 
send  a  certain  number  of  current  impulses  over  a  line  to  the 
receiver  when  the  corresponding  numbered  disk  is  pushed.  The 
receiver  consists  of  a  magnet  operating  an  armature,  ratchet 
and  the  pointer  on  the  face  of  the  instrument,  the  ratchet  limit- 
ing the  action  of  each  impulse  to  a  certain  movement  designed 
to  rotate  the  pointer  from  one  number  to  the  next.  Means  are 
provided  for  manually  operating  the  receiver,  if  necessary,  to 


Transmitter.  Receiver. 

Figs.    2605-2606.     Train    Describing    Instrument.      The   Union  Switch   &  Signal  Company. 


cover,  which  is  easily  removable,  but  which  may  be  locked  if 
desired.  The  indicator  "is  a  "unit"  construction  which  can  be 
grouped  on  shelves,  or  screwed  to  the  wall  in  the  manner 
shown  in  the  C.  &  N.  W.  Ry.  installation,  Fig.  2602. 


correspond  with  the  transmitter  by  pushing  the  button  on  the 
lower  left-hand  side.  Bells  are  usually  employed  in  addition 
to  the  instruments  shown.  Fig.  2617  shows  train  describers 
in  place  on  a  director  board. 


372 


ACCESSORIES. 


Figs.  2607-2610 


Side  View  Arrangement  of  Coils  and   Contacts.  Rear  View  of  Single  Unit. 

Figs.  2607-2608.     Multiple   Unit   Indicator  with   Wooden    Case.     The  Union  Switch   & 

Signal  Company. 


Fig.     2609.     Semaphore    Indicator.       Genera!     Railway      Fig.    2610.     Semaphore     Indicator.       (Fig.    2609)    with 
Signal  Company.  Case  Removed. 


Figs.  2611-2614 


ACCESSORIES. 


373 


Figs.  2611-2612.     Semaphore  Indicator.     American  Railway  Signal 

Company. 


Fig.  2613.     Iron  Case  Indicator,  with  Enclosed  Pointer, 

Polarized  Type.     The  Union  Switch  & 

Signal   Company. 


Fig.    2614.      Iron    Case    Semaphore    Indicator,    Neutral 
Type.     The  Union  Switch  &  Signal  Company. 


374 


ACCESSORIES. 


Figs.  2615-2619 


Fig.  2616.     Electro-Pneumatic     Interlocking     Machine, 

with      Illuminated      Indicators      Beneath  Levers. 
Delaware,  Lackawanna  &  Western.     The 
Union  Switch  &  Signal  Company. 


Fig.  2615.     Illuminated  Track  Indicator  and  Operator's 
Desk.     Interborough  Rapid  Transit  Company. 


In   Fig.   2616   the  Illuminated   Indicators   on   the  front   of  the 
machine   are   on   the   "Ledge,"    indicated    in    the   illustration. 


Fig.  2617.     Train  Director's  Board  and  Instruments,  Dek 

ware,  Lackawanna  &  Western.     The  Union 

Switch  &  Signal  Company. 


Figs.   2618.     Train  Director's  Board    (Fig.  2619)    with    Case 
Open.     Showing  Details  of  Wiring  and  Connections. 


Fig.  2619.     Train   Director's  Board.     Gen- 
eral Railway  Signal  Company. 


Figs.  2620-2624 


ACCESSORIES. 


375 


Names  of  Parts  of  Lamp  Indicator  Apparatus;  Fig.  2621.          indicator 


Thcnnostatc  Circuit  Controllers  K 

Expanding  Spiral  L 

Contact  Post  M 

Bell  N 

Bell  Battcr\  P 

Relay  Q 

Spool  Lightning  Arrester  R 

Pointer  S 


Banner 

Adjustable  Slop 
Coil  Terminal 
Ground  Terminal 
Bell  Circuit  Terminal 
Line   Terminal 
Coil  Terminal 
Line  Battery 


1-00 


Fig.   2620.     Arrangement  of   Circuits   for   Operating 
One    Bell    from    Several    Lamp    Indicators. 


Fig.  2621.     One  Indicator  Connected  to  Operate  with  Two  Lamps. 
Figs.  2620-2621.     Circuits  for  Lamp  Indicators.     Great  Western   Railway  of  England. 


I, AMI'     INDICATOR. 

Figs.   2020-2621   show   the   circuits  and  apparatus   used  by  the 
Great   Western  Railway  of  England,  to  indicate  to  a  signalman 


whether  or  not  the  signal  lamps  are  lighted.  In  the  illustration 
two  thermostats  A  are  shown,  one  for  each  of  two  lamps.  The 
thermostat  consists  of  a  spiral  of  readily  expanding  metal  B, 


SOO  V.  4  C  Mains 


Figs.    2622.     Typical    Arrangement   of 
Circuits,      East      River      Tunnels. 
Showing  Circuits    Controlling 
Track  Indicator,  Fig.  2615. 


Figs     2623-2624.     Circuits    for     Track 

Indicator.      Electric    Zone,     New 

York       Central      &     Hudson 

River.      General    Railway 

Signal    Company. 


376 


ACCESSORIES. 


Figs.  2625-2629 


connected  electrically  to  the  battery  S.  The  other  side  of  the 
battery  is  connected  to  ground.  When  the  lamp  is  lighted  the 
spiral  B  expands  and  makes  contact  at  C,  completing  the  circuit 
from  battery  S,  through  the  thermostat  controller,  coil  of 
the  indicator,  coils  of  the  relay  to  ground  (terminal  N),  back  to 
battery.  This  energizes  the  indicator  and  the  pointer  II  moves 
the  banner  K  so  as  to  show  "In"  at  an  opening  in  the  covet 
(not  shown).  If  one  of  the  lamps  is  extinguished  its  thermo- 
stat opens  the  circuit  and  de-energizes  the  indicator,  causing  the 
banner  to  display  "Out."  The  indicator  is  constructed  like 
block  indicator  shown  in  Fig.  341,  and  operates  in  the  same 
manner.  F  is  a  relay  controlling  the  bell  D.  The  adjustable 
stop  L  on  the  indicator  limit  the  travel  of  II. 

A  local  circuit  is  operated  by  the  back  contact  on  the  relay 
F  to  ring  the  bell  in  case  any  lamp  should  go  out.  In  the 
daytime,  when  the  lamps  are  not  needed,  the  bell  *  circuit  is 
cut  out  by  the  switch  shown  just  beneath  the  lightning  arrester. 

FEDERAL  TRACK  INDICATOR. 

In  the  track  indicator  made  by  the  Federal  Signal  Co.,  the 
different  track  circuit  sections  are  represented  by  a  length 
of  tube  supported  at  the  ends  so  as  to  be  free  to  revolve. 
These  tubes  are  so  placed  that  a  portion  is  displayed  through 
slots  cut  in  the  front  plate,  upon  which  the  track  and  con- 


Fig.  2625.     Front  View  (Glass  Removed)  of  Illuminat.- 

ed  Track  Diagram.     Chicago  &  North-Western. 

General  Railway  Signal  Company. 


Fig.  2627.     Illuminated  Track  Diagram.     Electric  Zone.     N.  Y. 
C.  &  H.  R.  R.  R.    General  Railway  Signal  Company. 


nections  and  signals  are  drawn.  If  the  track  is  occupied  or 
not  clear,  the  portion  of  the  tube  showing  through  the  slot 
in  the  front  plate  will  be  red,  whereas  if  the  track  is  un 
occupied  and  clear  the  part  of  the  tube  showing  will  be 
white.  The  tubes  are  operated  by  electro-magnets  controlled 
through  the  track  circuits  ;  and  these  electro-magnets  can  be 
arranged  for  direct  or  alternating  currents. 

G.    R.     S.     TRACK    INDICATOR. 

Figs.    2627-2629    illustrate    a    track    indicator    illuminated    by 
electric    lights    and    typical    circuits    for    operating    same.      The 


Fig.  2626.     Rear  View  of  Illuminated  Track  Diagram. 

Chicago  Terminal.     Chicago  &  North-Western. 

General  Railway  Signal  Company. 

indicator  consists  of  a  box,  the  cover  of  which  contains  a 
glass  plate  painted  to  show  a  diagram  of  the  tracks,  switches 
and  signals  concerned.  The  part  representing  the  sections 
covered  by  the  track  indicator  is  transparent,  the  rest  being 
opaque.  Within  the  box  are  rows  of  electric  lights  correspond 
ing  to  the  transparent  track  sections  on  the  glass.  Each 
row  of  lights  is  enclosed  in  a  small  channel  so  that  the  light 
can  shine  only  at  right  angles  to  the  back  of  the  box,  and  each 
row  is  divided  to  correspond  with  the  track  circuit  sections. 
The  lights  are  alternately  red  and  white.  When  a  track  section 
is  unoccupied  the  white  lights  burn  ;  the  presence  of  a  train 
extinguishes  them  and  causes  the  red  lights  to  burn,  so  that 
the  signalman  is  kept  constantly  informed  of  the  conditions 
of  the  track  sections  at  his  plant.  The  apparatus  illustrated 
was  made  by  the  General  Railway  Signal  Company  and  in 
stalled  on  the  Electric  Zone  of  the  New  York  Central  &  Hudson 
River,  and  at  the  Chicago  Terminal  of  the  Chicago  &  North 
Western  Railroad. 

D.     S.     &     S.    TRACK    INDICATOR. 

Figs.  2615  and  26iZ  illustrate  a  track  indicator  designed  by 
the  Union  Switch  &  Signal  Company  and  installed  in  connec- 
tion with  the  automatic  block  signals  in  the  East  River  tun 
ned  of  the  Interborough  Rapid  Transit  Company.  As  will  be 
seen  from  a  comparison  of  the  circuit  diagrams,  it  is  operated 
in  the  same  manner  as  the  indicator  illustrated  in  Figs.  2627- 
2628,  the  principal  difference  being  that  green  lamps  are  used 
instead  of  white  to  indicate  that  the  track  is  unoccupied. 

Fig.  2616  shows  an  illuminated  indicator  attached  to  the 
levers  of  an  electro-pneumatic  interlocking  machine,  which  shows 
when  the  track  section  in  which  the  function  occurs  Is  occu- 
pied by  a  train.  This  is  accomplished  by  an  electric  light 
behind  a  ground  glass  beneath  each  lever.  When  the  track 
section  is  unoccupied  the  light  burns. 


2628.     Track   Indicator   Shown  in   Fig.  2627,  with 
Glass   Front  Raised   Showing  Arrangement  of 
Lamps  and  Channels. 


Fig.  2629.     Typical   Circuits  for  Track  Indicator  Ope- 
rated  by   Alternating   Current.     General   Rail- 
way   Signal    Company. 


Figs.  2630-2632 


ACCESSORIES. 


377 


SWITCH  INDICATORS. 


Where  switches  occur  in  block  signalled  territory  they  are 
frequently  protected  by  switch  indicators.  These  may  'give  a 
visual  or  audible  indication  or  both.  Visual  indications  are 
given  by  an  electrically  operated  semaphore  arm  or  disk 
mounted  in  an  iron  case  on  a  post.  Audible  indications  are 
given  by  bells.  Indicators  are  placed  near  the  switch  and  are 
controlled  by  circuits  in  such  a  manner  as  to  announce  the 
approach  of  a  train  by  the  horizontal  position  of  the  arm, 
presence  of  the  disk  or  ringing  of  the  bell  when  the  train  is  a 


Fig.   2630.     Switch   Indicator   with    Push    Button. 
Signal    Company. 


Hall 


certain  distance  away,  usually  when  it  is  approaching  the  dis- 
tant signal  for  the  block  in  which  the  switch  occurs.  When 
such  announcement  is  given  the  switch  must  not  be  opened 
until  the  train  has  passed. 

AMERICAN     SIGNAL,     COMPANY'S     SWITCH     INDICATOR. 

The  American  Hallway  Signal  Company  makes  the  semaphore 
switch  indicator  shown  in  Figs.  2643-2644.  The  mechanism  is 
contained  in  a  cast  iron  case  designed  to  be  screwed  on  top  of 
a  pipe  post.  The  magnet  is  mounted  vertically,  the  armature 
below,  and  operates  the  semaphore  arm  by  an  up  and  dowu 
rod  and  a  lever. 

Figs.  2650-2651  show  a  semaphore  switch  indicator  with 
rotary  armature  and  differential  coils.  The  armature  is  of  the 
Z  type  and  actuates  the  arm  direct.  There  are  two  windings  on 
the  magnet,  one  of  a  low  resistance,  which  operates  the  indi- 
cator, and  one  of  high  resistance,  which,  in  series  with  the  first, 


holds  the  indicator  in  the  clear  position.     The  high   resistance 
is  controlled  by  a  circuit  breaker  on  the  shaft. 

The  alternating  current  switch  indicator  (Figs.  2658-2659)  Is 
provided  with  an  electric  light  mounted  on  the  door,  which 
illuminates  the  face  at  night. 

G.     R.     S.     rXIVERSAI,     POLYPHASE     INDICATOR. 

The  Indicator  shown  in  Figs.  2646-2647  is  of  the  same  con- 
struction  as  the  General  Railway  Signal  Company's  Model  2 


Fig.   2631.     Switch    Indicator  with  Pusli    Button. 
Signal   Company. 


Hall 


Fig.   2632.     Double    Switch    Indicator   and    Pest. 
Signal   Company. 


Hall 


378 


ACCESSORIES. 


Figs.  2633-2642 


Fig.  2633.     Siding  Bell 
Box. 


Figs.       2634-2635.        Style 

"A"  Switch  Indicators. 

Railroad    Supply 

Company. 

[Fig.  2634  shows  the  Indica- 
tor equipped  with  'vibratory 
bell  and  push-button  box.] 


SECTIONAL  PLAN  VIEW 


SECTIONAL  PLAN  VIEW 


Fig.  2636.  Universal  D. 
C.  Switch  Indicator.  Mod- 
el 9,  Form  "A."  General 
Railway  Signal  Company. 


FRONT  VIEW 


SECTIONAL  SIDE  VIEW 


FRONT  VIEW 


SECTIONAL  SIDE  VIEW 


Figs.    2637-2639.     D.    C.    Iron    Case    Switch    Indicator.      Figs.    2640-2642.     A.    C.    Iron    Case    Switch    Indicators. 
The  Union  Switch  &  Signal  Company.  The  Union   Switch    &   Signal   Company. 


Figs.  2643-2649 


ACCESSORIES. 


379 


igs.  2643-2644.    Semaphore  Switch  Indicator.     American  Railway  Signal  Company. 


Fig.     2645.     Switch     Indi- 
cator   on     Iron    Post. 
Hall   Signal  Com- 
pany. 


Form  A  polyphase  relay.  The  case  is  designed  to  accommo- 
ite  a  terminal  board  and  lightning  arrester. 
The  <;.  U.  S.  Co.'s  polyphase  relays  and  indicators  are  ope- 
rated by  means  of  a  two-phase  induction  motor  (track  and 
local  phase).  Each  of  these  two  windings  must  be  supplied 
with  current  having  the  proper  phase  relation,  polarity  and 


frequency  to  ensure  operation  of  the  relay.  It  is  rendered  im- 
mune to  foreign  or  track  current  by  the  use  of  the  G.  R.  S. 
non-magnetic  rotor.  The  design  is  such  that  the  breaking 
down  of  insulated  joints  will  cause  the  relay  contacts  to  open. 
Fig.  2636  shows  the  Universal  D.  C.  switch  indicator.  Model 
9  Form  A,  made  by  the  General  Railway  Signal  Company. 


Figs.    2646-2647.     Universal    Polyphase    Switch    Indica- 
tor, Model  2,  Form  "A."     General  Railway 
Signal  Company. 


X 


Figs.   2648-2649.     Semaphore     Switch     Indicator 
Rotary  Armature  and  Differential  Coils. 


with 


ACCESSORIES. 


Figs.  2650-2655 


Figs.  2650-2651.     Details  of  Semaphore  Indicator. 


HALL     SWITCH      INDICATORS      . 

Figs.  2630-2631  show  the  mechanism  of  the  switch  indicator 
made  by  the  Hall  Signal  Company,  and  a  front  view  of  the 
indicator.  This  instrument  is  equipped  with  a  push  button 
which  is  mounted  on  the  lower  side  of  the  indicator  case  as 
shown  in  the  figures. 

A  disk  switch  indicator,  which  gives  night  indications,  is  illus- 


Defailof 

WeaffierS/iield. 


Figs.  2652-2653.     Semaphore  Switch  Indicator  with  Bell    \  Figs.    2654-2655.     Siding    Bell    Box.      Railroad    Supply 
Added.  L_  Company. 


Figs.  2656-2659 


ACCESSORIES. 


trnted  in  Figs.  2652-2653.  A  disk  which  carries  a  colored  ccllu- 
Icid  center  is  moved  in  front  of  the  white  lens  of  a  lamp  by  being 
connected  to  the  Z  armature  of  an  electromagnet.  The  presence 
of  current  in  the  magnet  raises  the  disk  to  show  a  clear  signal, 
while  the  absence  of  current  causes  a  counterweight  to  restore 
the  disk  to  the  stop  or  caution  position.  This  illuminated  type  is 
used  most  frequently  in  yards  where  the  indicators  must  be  placed 
at  some  distance  from  the  switch  because  of  insufficient  clearance 
between  tracks  for  the  usual  type.  These  instruments  may  be 
used  at  exits  to  passing  sidings  instead  of  dwarf  signal?. 
Wires  arc  brought  up  through  the  base  and  the  pipe  post.  The 
mechanism  is  enclosed  in  an  iron  case  which  has  a  removable 
back. 

Figs.  2663-2665  illustrate  a  semaphore  switch  indicator  made 
by  the  Union  Switch  &  Signal  Company.     It  consists  of  a  mag- 


direction  of  the  current  in  the  coils  of  the  electromagnet.  The 
permanent  magnet  actuates  a  pointer  which  stands  vertical 
normally  and  swings  to  one  side  or  the  other  in  synchronism 
with  the  permanent  magnet.  This  type  of  indicator  is  designed 
to  cover  the  field  whereby  indication  at  a  distance  may  be  had 
of  the  condition  of  two  or  more  devices  or  mechanisms.  It  is 
especially  suited  to  railway  signaling  for  indicating  to  a  train- 
man at  an  outlying  passing  siding  switch  :  First,  the  approach 
of  a  train  ;  second,  the  movement  of  the  signal  controlling  the 
track  section  in  which  the  switch  occurs,  to  a  position  cor- 
responding to  that  of  the  outlying  switch.  In  automatic  block 
signaling  it  may  be  desirable  that  a  trainman  have  positive 
information  relative  to  main  line  conditions  when  about  to 
open  a  switch  leading  to  the  main  line,  and  having  opened  such 
switch,  that  the  main  line  signal  has  moved  to  the  stop  position. 


Fig.   2656.     Semaphore   Switch   In- 
dicator   Mounted    on    Iron    Pipe 
.    Post    Set   on    Cast    Iron    Base, 
Embedded    in    Concrete 
Foundation. 


Fig.      2657.          Semaphore 
Switch  Indicator.  Rail- 
road Supply  Com- 
pany. 


Figs.  2658-2659.  Illum- 
inated Alternating  Cur- 
rent Semaphore  Switch 
Indicator.  General  Rail- 
way Signal  Company. 


net  mounted  in  an  iron  case  which  operates  a  semaphore  arm 
through  its  armature  and  a  crank  and  link.  The  armature  is 
below  the  magnet  and  the  semaphore  arm  is  carried  on  a  shaft 
above  the  magnet.  The  shaft  projects  through  a  white  face 
plate  used  as  a  background  for  the  arm.  In  the  figure  Is 
shown  a  cast  iron  pipe  post  and  foundation  combined. 

The  semaphore  switch  indicator  with  bell  (Figs.  2669-2671), 
made  by  the  Union  Switch  &  Signal  Company,  is  in  all  respects 
like  the  indicator  shown  in  Figs.  2663-2665,  except  for  the 
addition,  below  the  indicator  head,  of  a  bell  box  containing  the 
bell.  Two  types  are  shown. 

The  polarized  switch  indicator  made  by  the  Union  Switch  & 
Signal  Company,  shown  in  Figs.  2672-2674,  consists  of  an 
electromagnet  between  the  poles  of  which  Is  suspended  a 
permanent  magnet.  When  the  electromagnet  is  de-energized  the 
permanent  magnet  assumes  a  neutral  position,  being  held  by 
springs.  When  the  electromagnet  Is  energized,  the  permanent 
magnet 'is  attracted  to  one  side  or  the  other,  according  to  the 


and  that  the  opening  of  the  switch  was  the  cause  of  setting 
the  signal.  The  ordinary  neutral  type  of  indicator  does  not 
fulfil  these  conditions.  Should  a  train  enter  the  main  line 
section  at  the  instant  the  switch  was  opened  by  a  trainman,  it 
is  possible  that  the  trainman  might  assume  that  his  act  of, 
opening  the  switch  had  set  the  main  line  signal  and  his  train 
would  move  out  onto  the  main  line,  which  might  cause  delay 
to  an  approaching  train ;  or  he  might  assume  that  a  train  was 
at  the  setting  section  for  the  indicator  and  move  out  onto  the 
main  line  expecting  the  approaching  train  to  be  held  at  the 
home  signal,  when  In  reality  the  approaching  train  had  passed 
the  signal  and  was  in  the  block  containing  the  passing  siding 
switch,  thereby  causing  a  collision  risk.  It  may  be  used  at 
slotted  signals  at  interlocking  plants  to  indicate  an  approach- 
ing train,  the  clearing  of  the  signal,  and  its  return  to  the  stop 
position  ;  or  it  may  be  used  to  indicate  whether  or  not  a  signal 
light,  not  visible  from  the  tower  or  other  point,  is  in  proper 
condition  at  night ;  or  for  other  similar  purposes. 


382 


ACCESSORIES. 


Figs.  2663-2668 


Figs.    2666-2668.        Illumi 
nated  Disk  Switch  In- 
dicator.     The      Un- 
ion Switch  &  Sig- 
nal   Company. 


Figs.   2663-2665.    Sema- 
phore    Switch     Indi- 
cator.    The  Union 
Switch   &   Signal 
Company. 


Figs.  2669-2674 


ACCESSORIES. 


383 


Fig.  2672.     Mechanism   of  Polarized   Switch  Indicator. 


Fig.    2673-2674.     Polarized    Switch    Indicator    Mounted 
Figs.  2669-2671.     Semaphore  Switch  Indicator  with  Bell.  on  Iron  Pipe  Post.     The  Union  Switch  & 

The  Union  Switch  &  Signal  Company.  Signal   Company. 


ACCESSORIES. 


Figs.  2675-2679 


RAILWAY  SIGNAL  LAMPS 


There  are  now  in  use  a  great  variety  of  signal  burners  ranging 
from  the  largest  flat  wick  chimneyless  burners,  with  flame 
1  3-8  in.  in  diameter  or  more  at  the  optical  axis  and  illumina- 
tion of  three  c.  p.,  to  the  small  round  flame  chimney  burners 
with  flame  diameter  of  3-16  in.  and  0.25  and  0.35  c.  p. 
Burners  of  the  larger  sizes  are  commonly  known  as  "one 
day"  burners,  being  designed  for  daily  attendance.  Many  rail- 
way men  favor  them  to-day  for  use  wherever  conditions  permit, 
on  account  of  the  increased  spread  of  light  from  lanterns  and 
the  superior  stability  of  flame  in  windy  weather.  These 
burners  are  open  to  one  serious  objection,  the  large  flame  and 
the  small  size  of  the  present  signal  lanterns  combine  to  raise 
the  temperature  of  the  oil  pot  beyond  the  safety  point  in  hot 
weather,  especially  with  oil  running  as  low  as  125  deg.  F. 
fire  test,  which  is  not  infrequent.  Lanterns  so  equipped  have 
more  than  once  caught  fire,  though  the  danger  from  this  would 
not  be  great  were  150  deg.  test  oil  used. 

Wool,  cotton,  sand,  asbestos  and  glass  have  all  been  tried 
for  wicks ;  chemical  treatment  has  been  employed  and  the 
mechanical  construction  of  wicks  varied  in  the  hope  of  re- 
ducing or  eliminating  crust.  All  kerosenes  form  crust  when 
burning,  no  matter  what  the  material  of  the  wick,  and  a  fail- 
test  considers  the  quality  rather  than  the  quantity  of  this  crust. 


the   extreme   limits   of   colors   which   it    is   proposed   to   furnish. 
These  shall  bear  labels  showing  the  photometric  values,  and  If 

approved  will  be  kept  in  the  office  of 

as  standards. 
Rejected  Material. 

The  purchaser  will  notify  the  manufacturer  promptly  as  to 
rejected  material,  which  will  be  retained  not  longer  than  two 
weeks  from  date  of  notification.  If  at  the  end  of  that  time 
the  manufacturer  has  not  advised  the  purchaser  as  to  disposi- 
tion, such  materials  will  be  returned  to  the  manufacturer  at 
his  risk,  the  manufacturer  paying  the  freight  both  ways  in 
either  case. 
Design.  ROUNDELS 

Roundels  must  be  of  diameter  specified  in  order,  and  between 
.21-inch  and  .20-inch  thick. 

Roundels  will  be  subject  to  spectro-photometric  analysis 
The  following  table  gives  an  analysis  of  roundels  of  the  vari 
ous  colors  of  medium  intensity,  the  letters  indicating  lines  of 
the  spectrum,  and  the  figures  showing  percentages  of  light 


Train     Order     Lan- 
tern with  Double 
Fresnel  Lens. 


Signal    Lantern    with 

Single  Fresnel 

Lens. 


Semaphore    Lantern 

with          Electric 

Burners. 


Round    Body     Steel 
Lantern    (Closed). 


Round     Body     Steel 

Lantern        (Top 

Draft). 


Figs.    2675-2679.     Switch   and    Signal    Lanterns.      Peter    Gray    &   Sons. 


A  dry,  brittle  formation  will  crack  at  intervals  and  fall  apart, 
leaving  crevices  through  which  the  gas  from  the  hot  wick  may 
escape,  while  a  tarry  crust  will  in  short  order  completely 
seal  up  the  top  of  a  wick  and  extinguish  the  flame.  Wicks 
have  been  impregnated  with  chemicals  designed  to  cause  dis- 
integration of  this  crust,  but  the  improvement  has  been  slight, 
If  any.  The  best  results  have  been  obtained  by  allowing  the 
wick  to  fit  as  loosely  as  possible  in  its  tube  and  by  incor- 
porating in  the  wick  channels  or  cores  parallel  to  its  length. 


R.   S.   A.    SPECIFICATIONS   FOR   SIGNAL  ROUNDELS^  LENSES   AND 
GLASS    SIDES. 

Material.  GENERAL. 

All  glasses  must  be  of  clear  uniform  solid  color,  containing 
the  highest  proportions  of  lead  compatible  with  durability  and 
securing  the  required  color  and  must  have  a  specific  gravity  of 
not  less  than  2.75.  Chipped  or  flashed  glasses  will  not  be  ac- 
cepted. 
Workmanship. 

Workmanship  shall  be  of  the  best,  and  glasses  must  be  true 
to  size  and  form,  and  practically  free  from  bubbles,  streaks,  and 
wrinkles. 
Color. 

Red,  green,  yellow,  blue,  purple  and  lunar  white  glasses  will 
be  purchased. 
Wrapping. 

Each  glass  must  be  wrapped  in  paper  of  corresponding  color. 
Tests. 

The   manufacturer  must  test   each   glass,   placing  thereon   a 
label  showing  the  photometric  value. 

The  purchaser  reserves  the  right  to  make  repetition  of  the 
above  test,  to  insure  that  only  material  meeting  the  require- 
ment is  accepted,  and  all  materials  not  meeting  such  require- 
ments will  be  rejected.  All  red  glasses  must  be  submitted  to 
the  sodium  test. 
Samples. 

The  manufacturer  must  submit  samples  of  glasses,  showing 


A 

Red     60 

Green     , .  .    0 

Yellow     0 

Blue    0 

Purple     0 

Lunar    White. . ,  .0 


F 

0 
45 

3 
24     40     46 

2     43     42 
65     74       0 


G 

0 

25 

0 


transmission  at  the  different  points.  Roundels  of  medium  in- 
tensity should  transmit  light  as  nearly  as  possible  of  this  com- 
position, a  reasonable  variation  being  allowed  for  light  and 
dark  limits. 

a      B      C       D      E      b 
65     70     72       0       0       0 
0       0       0       4     27     40 
38     50    43     41     12       9 
0       0       0       3       4       6 
42     42       0       0       0       0 
62     49     17     15     25     38 
Briefly   describing   the   above  photometric   values. 
Red. 

Will  be   of   such  quality   that   all   yellow   rays   of   light   are 
absorbed,    the    spectrum    being    either    red    or    red   and    orange. 
The    photometric    value    shall    be,     light    130,    standard    100, 
dark  70. 
Green. 

Will    be   of   the    color   known    as    Admiralty    green,    having   a 
slightly  bluish  tint.    The  spectrum  shall  show  very  little  yellow, 
being  a  full  green  with  some  blue.    The  photometric  value  shall 
be,  light  125,  standard  100,  dark  75. 
Yellotv. 

Will  give   a   spectrum   showing  a  full   yellow  band,   most  of 
the  red  and  slightly  of  the  green.    The  photometric  value  shall 
be,  light  120,  standard  100,  dark  80. 
Blue. 

Will  give  a  spectrum  having  a  full  blue  band,  with  a  narrow 
band    of    green.     The    photometric    value    shall    be,    light    125. 
standard  100,  dark  75. 
Purple. 

Will   give  a   spectrum   showing  a   considerable   proportion  of 
both  red   and  blue.   The   photometric  value  shall  be  light  125, 
standard  100,  dark  75. 
Lunar  White. 

Shall   show   a  maximum   of 'absorption  for  the  yellow.     The 
photometric  value  shall  be,  light  120,  standard  100,  dark  80. 


Figs.  2680-2687 


ACCESSORIES. 


385 


J.EXSES. 

Tin-    Railway    Signal    Association    specifications    for    linses    arc 
as   follows  : 
Design. 

All  lenses  must  he  of  the  optical  pattern,  focusing  to  a 
plane  rather  than  to  a  point,  and  must  he  of  the  polyzonal 
typo,  with  smooth  outer  face.  All  parts  of  the  lens  must  focus 
i.i  ,in  area  not  exceeding  •%  inches  in  diameter  for  all  lenses 
up  to  the  six-inch  size,  nor  exceeding  \'.,  inch  in  diameter  for 
the  larger  sizes;  must  be  so  designed  that  the  divergence  of  the 
projected  heam  (i.  e.  spread),  with  flame  one  inch  broad,  shall 
not  exceed  one  foot  from  the  axis  in  eight  feet.  When  ob- 
served at  a  distance  of  30  or  40  feet,  a  small  flame  oil  burner 
being  placed  in  the  focus,  the  whole  lens  shall  be  equally  illumi- 
nated, the  "risers"  on  the  inner  surface  showing  only  as  narrow 
dark  rings. 

All  lenses  <>%  inches  and  over  diameter  must  have  at  least 
five  zones,  and  the  smaller  lenses  four,  and  must  be  corrugated 
inside. 


Color. 

Colored    corrugated    lenses    must,    have    the    same    photometric 
and   spcctro-photometric   values   as    roundels   of  the   same   color, 
but  allowance  will  be  made  for  divergences  due  to  irregularities 
of  manufacture. 
Focus. 

The  focus  of  each  lens  must  be  stamped  on  the  outer  zone. 


CLASS     SLIDES. 

The     Railway     Signal     Association     specifications     for     glass 
slides  are  as  follows  : 
Material. 

The   glass   must   be   double   thick,   and   of   the   same   character 
of    material    as    furnished    for    lenses    and    roundels.     Thickness 
of   slides   shall   be  not   less   than   .005    inch   and   not   more   than 
.15  inch. 
Design. 

Slides    must    be    cut   or   pressed    to    size    ordered. 


Fig.  2680.     Semaphore  Lantern.  Dres- 
sel  Railway  Lamps  Works. 


Figs.    2681-2682.     Semaphore    Lamps    Equipped    with     Long 
Time   Burners.      The   Adams   &  Westlake    Company. 


[Note. — The  Lonj 
in  Detail  in  Fig.  2701.] 


Time  Burner  Shown  in   Fig.  2681   is  Shown 


Figs.  2683-2685.     Steel  Switch  Latnt^j,     Dressel  Railway  Lamp  Works. 


Fig.  2686.  Sem- 
a  p  h  o  r  e  Lamp. 
Dressel  Railway 
Lamp  Works. 


Fig.  2687.  Sem- 
aphore Lantern 
with  Acetylene 
Burner.  Peter 
Gray  &  Sons. 


386 


ACCESSORIES. 


Figs.  2688-2698 


k-      •  -/<?-       


2691.     Non-Sweating  Balanced  Draught 
Lamp.     The  Adams  &  Westlake 
Company. 


Figs.  2688-2690.     Distant  Signal  Lamp.      Chicago    &    Nofth- 
Western. 

ADLAKE   NON-SWEATING  BALANCED   DRAUGHT. 

Adlake  non-sweating  balanced  draught  lamps  are  designed 
to  eliminate  precipitation  of  moisture  or  "sweating,"  irrespect- 
ive of  varying  temperatures  or  wind  pressure.  The  accomplish- 
ment of  this  result  secures  three  important  ends:. 

1st — Lenses  are  kept  clear  and  no  moisture,  frost  or  ice  re- 
tards the  passage  of  light. 

2d — The  corrosion  of  lamp  bodies  is  prevented. 

3d — The  burner  flame  is  fully  protected  to  withstand  severe 
winds.  All  types  of  lamps  can  be  equipped  with  this  ventila- 
tion. 


Back  Light 
Double  Wick  Milk  Glass . 


for  Back  Light. 


±'6lass  Chimney 
''•""•t.Dia. 


Lamp  Wick  5 

r*    RedLight  jj 

S'LongtteDia.  v 
•No.4  Blank  Screw 


\  ^ 

I! 


*]& 


Fount Cover  XX 'Tin  __ 


Fount  Body 
No.245ttel(DraK 


Figs.  2692-2698.     Semaphore  Lamp  and  Details.     Pennsylvania  Railroad. 


Figs.  2699-2713 


ACCESSORIES. 


387 


T 


Fig.    2699.     Long    Burning    Fount 

with     Prism    Glass      Reflector. 

The  Adams   &  Westlake 

Company. 


Fig.   2700.     Long     Burning     Fount 
with  One-way  Metallic  Reflec- 
tor.    The  Adams  &  West- 
lake  Company. 


Fig.  2701.  Long 
Time    Burner. 
The       Adams     & 
Westlake       Com- 
pany. 


Fig.   2706.     2O-Oz.    (One   Day)    Oil 

Fount.      The    Adams     & 

Westlake    Company. 


Fig.  2707.  31- 
Oz.  Oil  Fount. 
Dressel  Railway 

Lamp   Works. 


Figs.    2702-2705.      Chimneys 


Fig.  2708.     Drawn  Steel  Oil  Fount. 
3i-Oz. 


Fig.    2710.     Base   and    Burner   of    Chimneyfess 

Burner.     Peter  Gray  &  Sons. 
Fig.  2709.  Electric 
Top    Socket.      Dres- 
sel    Railway     Lamp 
Works. 


Fig.  2712.  Long 
Time  Burner. 
Dressel  Railway 

Lamp  Works. 


Fig.  2711.     Steel   Flame  Spreader  Detached  from  Base 
of   Chimneyless    Burner.     Peter   Gray   &   Sons. 


Fig.   2713.     32-Ounce   One  Piece  Fount  with  Chim- 
neyless    Burner     for     Switch     and      Semaphore 
Lanterns.      Also    Made    in    20-02.    Size. 
Peter   Gray  &   Sons. 


388 


ACCESSORIES. 


Figs.  2714-2723 


Fig.   2715.     Electric   Socket.     Dres- 
sel   Railway  Lamp  Works. 

A 


Fig.      2716.       Twenty-four 
Hour    Burner.    Adams 
&  Westlake  Com- 
pany. 


.     2714.     Chimneyless        Burner 
omplete.  Peter  Gray  &  Sons. 


Fig.  2717.     Electric  Lights  for  Signal 

Lanterns.       One     Bulb     in     Circuit; 

Other    Automatically    Thrown    in 

Circuit   if   First    Fails.      Peter 

Gray    &    Sons. 


Fig.   2719.     Electric      Back     Socket.        Dressel 
Railway   Lamp    Works. 


Fig.  2718.   Electric 
Lamp       for       Sema- 
phore    Lamp.       The 
Adams    &    Westlake 
Company. 


Fig.    2720.     Electric    Socket.      Dressel    Rail- 
way Lamp  Works. 


'       1 


Fig.  2721.     Electric     Light     Burner. 
Adams  &  Westlake  Company. 


Fig.      2722.     Long  -  Burnirij 

Fount       with     Reflector. 
The  Dressel      Railway 

Lamp    Works. 


Fig.     2723.     Long  -   Burning* 

Fount.     Dressel   Railway 

Lamp    Works. 


Figs.  2724-2730 


ACCESSORIES. 


389 


Fig.  2725.     No.   i   Low  Dres 
sel  Burner.     Dressel  Rail- 
way   Lamp    Works. 


Fig.  2724.     Long-Time  Burner.     The  Adams  &  West- 
lake    Company. 


Fig.    2726.       Twenty-four    Hour 

Burner.     Dressel   Railway 

Lamp    Works. 


Fig.    2727.      Train    Order    Semaphore    Lamp. 
The  Adams  &  Westlake  Company. 


Fig.    2729.       Semaphore     Lamp. 
The    Adams    &    Westlake 
Company 


Fig.   2728.     Convertible    Semaphore  Lamp. 
The   Adams  &  Westlake   Company. 


Fig.  2730.     Crossing  Gate  Lamp.     The  Adams  &  West- 
lake  Company. 


390 


ACCESSORIES. 


Figs.  2731-2735 


/.     FOUNT  SHS1LL   BE   THIRTY  ONE  (3/)  FLUID 
OUNCe   CAPACITY  AND   FITTED    WITH  /? 
SLIP   COLLAR.   FIFTEEN-SIXTeENTHS{ff')OF AN 
INCH    IN   DIAMETER. 

3.    FOUNT  SMALL   BE  MADE  OF  NSSS.  DRAWN 
SHE*T  STEEL.   TINNED,  &NO  BOOY  PRESSED 
OUT  OF  ONE   PIECE  &/VD    WITH    TOP   SOLO-        ~^ 
£RED    ON. 
3.   LONG    TIM£  BURNER  SHALL  BE  USED.  -4C  J*^H 


Fig.    2734- 


S.     A. 


H 

FOUNT 

Lamp  Equipment. 


Fig.     2731.        Pier     or     Abutment 
Lamp.     The  Adams  &  West- 
lake  Company. 


I   BOOY  OF  LAMP  SHALL  Of  MAOC  OF 
NO. /6  •  SHEET  STECL  TINNED. 

Z  BOP*  OF  LAMP  SHALL   BE  SIX  flfilD 

OM-HALF (f>V)IHCH£S  IN   DIAMETER. 
3  RIVETS  SHALL   B£  US£D  IN  CONSTRUCTiQfj 

OF  THf  BOOY  OF  THE  LAMP  FOR 
HOLDING  PARTS   TOGETHER. 

4  DISTANCE  FROM  CENTRE  OF  LAMP  TO 
OUTS/Of  OF  LENS,  OR  LENS  SHIELD, 
SMALL  BE  NOT  MORE  THAN  FOUR  \ 

AND    THREE- FOURTHS  (4f)  INCHES,      f"] 

5  OfSTflMCE  FROM    CENTRE  OF  LENS 

TO  BrtSE  OF  LftMP  SHftLL.  BE  FIVE      \-J 
ANO  NINE- SIXTEENTHS  (  5.?)  INCHES 

6  DtSTftNCE  FROM  CENTRE       OF  LENS 
TO  BOTTOM  SUPPORT  OF  FOUNT  SHflLL 
BE  FOUR  a/VD  ELEVEN -SIXT£ENTHS(4f.)  INCh 

7  DISTANCE  FROM   CENTRE  OF  LAMP 

TO  CENTRE  OF  LAMP  SOCKET  SHflLL  BE 
THREE  AND  FIVE -EIGHTHS  (  3g  )  INCHES . 

8  CAAS  Off  BAIL  nooifS,  WHE°RE  USED, 

SHALL    BE  MflOE  OF  MtlLLEflBl-E  IRON 

RIVETED     TO  BODY  OF  LAMP.  r 

9  HANDLE  OF  LfIMP  SHAL  L    BE  NO.  f.B.W.G.S7  E£L    WIRE.   \_ 
0    DOOR  SHALL.  HAV*  WATER-SHED   SO 

ARRANGED  AS    TO  PREVENT  RAIN  ENTERING 

THE  LAMP ,  AND  aOOR  SHALL   RAISE  HIGH 

ENOUGH    TO  MAKE  THE  OPENING   SIX  AlvD 

FIVE- EIGHTHS  C  65  )  INCHES. 
II    LAMP  SHALL    BE°SO    CONSTRUCTED 

THAT  THE   WICK  ADJUSTMENT  SH&FT 

EXTENDS    THROUGH  BOOY  OF  LAMP. 
I  Z    LAMP  SHALL  HAVE  TOP  DRAUGHT  VEfi 

(VENTILATION  WILL  BE  TESTED  WHEN 

AT  THE  FACTORY  AS  FOLLOWS.  (A)  * 
VELOCITY-  EQUIVflLENV  TO  EIGHTY          „__ 

(80)  M.  p.  H.  FOR  TWO  (Z )  MINUTES  . 

(Q)ST/L,L  fJIff-  TEMPFRflTUffE  ONE 
HUNDRED  AND  TEAl(\\0)  DEGREES  FAHR. 
FOR  TWO  (Z) HOURS. /FflBOVE  TESTS  EX- 
TINGUISHES FLAME  LAMP  WILL  BE  REJECTED. 

1  3  LENS  SHALL  BE  FIVE  (5) INCHES  IN  DIAM- 
ETER WITH  THREE  AND  OHE-HOLF    (  3  J  ) 
INCH    FOCUS  . 

14    LENS  HOLDER  SHALL  BE  ARRANGED  SO  

THAT  LENS  CAN  BE  EASILY  REMOVED  AND 
SHALL  COMPLETELY  ENCIRCLE  THE  LENS. 

I  5    LAMP  SHALL  BE  PROVIDED  WITH  FIVE- 
EIGHTHS  (  I  )  INCH  BffC/f-LIGHT  WITH 

ONE  (\  \/N^:H  SCREW  CAP. 
I  6  SOCKET  OF  LAMP  SHAL  L  BE  ARRANGED 

TO  RECEIVE  ft  LAMP  BRf>CffET  ONE-HALF 
BY  TWO  (  J  X  2  )  INCH  DIMENSIONS . 
SOCfffT  NOT  TO  EXCEED  THe  DIMENSIONS 

OF  BRACKET  MORE  THAAI  ONE  -  S/Jf- 
TEEN  TH  (  |^  )/NCH  AND  BE  EIGH  T  (  8  )  IHCHfS 
IN  DEPTH ,  RECESSED  FOR  (OVAL-HEAD) 
THREE- EIGHTHS  (  |  )  INCH  RIVET. 
17  BACK-LIGHT  AND  PEEP-HOLE  GLASSES 

SHALL   ae  HELD  IN  PLACf  BY  SCREW 
RETA/WNG  RHVGS  . 
i  8    /NSCCT  SCREEN  SHflLL    BE  PROVIDED 


t    STffuCTt'ON    O> 
I    LAMP  a£\OVE  TH 
L/H£  IS  NOT  SPEC: 

\ 

MALLEflElLf  HOOK  OR     ' 
I    i      ;    FLAT  ST££I\PI£CE  TO      '       i    ' 
I    '     /  Bf/FUffflSHfa  AS  OfSlfffD       **} 


Figs.  2732-2733.     R.  S.  A.   Semaphore  Lamp. 


Fig.     2735.      Standard 
tern.        The      Adams 
Westlake  Company. 


Lan- 


Figs. 2736-2743 


ACCESSORIES. 


391 


Figs.         2736-2737. 

Standard       Railroad 

Lanterns.        The 

Adams    &    Westlake 

Company. 


Stop — Swung  Across   the   Track. 


Go    Ahead — Raised     and     lowered 
the     man     facing    toward     the 
person    to    whom    the    sig- 
nal   is    given. 


Back — Swung  vertically  in  a  circle 

at    half   arm's    length    across 

the  track. 


Train   Has    Parted — Swung     verti- 
cally in  a  circle  at"  arm's  length  Apply  Air-Brakes — Swung  horizon-         Release  Air-Brakes — Held  at  arm's 
across  the  track.  tally  in  a  circle.  length    above    the    head. 
Figs.  2738-2743.  Hand    Signals.     To   be   given   with    Hand   or    Lantern. 


392 


ACCESSORIES. 


Figs.  2744-2749 


LIGHTNING  ARRESTERS 


UNION    SPARK    GAP    LIGHTNING    ARRESTER. 

The  arrester  illustrated  in  Fig.  2746  consists  of  two  elec- 
trodes separated  by  a  spark  gap  and  carried  by  a  supporting 
plate  drilled  so  that  it  may  be  slipped  across  the  terminals  of 
the  relay  coils  (see  Fig.  2744)  so  that  no  wires  are  required  to 
connect  it  in  circuit.  This  arrester  acts  as  a  shunt  across  the 
coil  terminals,  which  becomes  effective  only  when  the  potential 
rises  to  an  abnormal  amount. 


L*     fc 


Figs.  2744-2745.     Brass  Plate  and  Glass  Tube  Types  of 

Spark  Gap     Lightning'     Arresters.       The     Union 

Switch    &    Signal    Company. 

It  is  built  in  two  forms  :  One  in  which  the  electrodes  con- 
sist of  two  thin  brass  plates,  separated  by  the  proper  air  gap 
and  bent  away  from  the  supporting  plate  at  the  air  gap  so  as 
to  avoid  the  accumulation  of  dirt  at  this  point  (Fig.  2745)  : 


Fig.    2746.     Spark    Gap    Lightning    Arrester    Mounted. 
The  Union  Switch   &  Signal  Company. 

and  the  other  in  which  ordinary  pins  carried  by  small  glass 
tubes  are  the  electrodes,  three  of  which  units  are  carried  on 
each  side  of  the  supporting  plate.  The  first  type  with  brass 
plate  electrodes  has  the  advantage  of  extreme  simplicity  and 
will  withstand  any  number  of  discharges  without  increase  of 
air  gap  due  to  the  burning  action  of  the  spark.  The  other  type 
with  pin  electrodes  is  more  sensitive  to  discharges  than  the 
brass  plate  form,  as  it  is  a  well  known  fact  that  point  elec- 


FH 


2747.     Spark  Gap  Arrester  for  Line  Service. 
Union    Switch    &    Signal    Company. 


trodes  will  discharge  at  a  lower  potential  than  blunt  ones, 
although  of  necessity  the  point  electrodes  are  more  affected  by 
the  burning  action  of  the  discharge.  However,  the  glass  tube 
arrester  may  be  depended  upon  to  carry  several  hundred  ordi- 
nary discharges  before  showing  a  decrease  in  sensitiveness  due 
to  increase  in  the  spark  gap.  This  type  of  arrester  may  be 
mounted  on  either  the  9-C  or  I'niversal  relay. 


G.     R.     S.     LIGHTNING     ARRESTER. 

Fig.  2748  illustrates  the  G.  R.  S.  Co.'s  Model  I  Form  A 
lightning  arrester,  designed  for  use  on  signal,  telegraph,  tele- 
phone and  crossing  alarm  circuits.  The  arrester  has  a  high 
efficiency,  i.  e.,  a  high  reactance  and  negligible  ohmic  resist 
ance.  This  high  reactance  is  maintained  under  all  condi- 
tions of  frequency  and  current,  owing  to  the  fact  that  no 
iron  is  used  in  the  core  of  the  reactance  coil. 

The  arrester  is  small  (15/16  in.  x  4%  in.  x  3%  in.),  and 
may  be  assembled  in  banks  on  15/16  in.  centers.  Connectors 
between  the  ground  plates  arc  provided,  which  form  a  bus-bar 
of  ample  carrying  capacity,  thereby  making  requisite  but  one 
ground  connection  for  any  number  of  arresters.  Multiple  point 
discharge  plates  are  provided  instead  of  the  single  point  type 


or  one  having  a  circular  surface.  No  delicate  or  easily  broken 
parts  are  used  in  the  arrester  construction.  The  connections 
are  all  in  front  for  easy  inspection  and  installation 

The   Model    I   Form   A  uses  the  same  component  parts   as  the 
Model    I    arrester. 


j.    2748.      Model    i,    Form    "A"    Lightning    Arrester. 
General  Railway  Signal   Company. 

GENERAL    ELECTRIC    DIRECT    CURRENT    LIGHTNING    ARRESTER. 

The  General  Electric  Type  M  Form  D-2  arrester  is  furnished 
for  circuits  from  60  to  800  volts.  The  spark  gap  and  non- 
inductive  resistance  are  in  a  straight  line,  thus  forming  a  direct 


Fig.  2749.     Type  "M"   Form  D-2.     Lightning  Arrester. 
General  Electric  Company. 

path  for  the  discharge  and  reducing  to  a  minimum  the  pcssibll- 
ity  of  short  circuit  in  the  box  in  case  of  excessively  heavy 
lightning  discharges.  All  parts  can  be  readily  inspected  on 
removing  the*  cover  of  the  porcelain  enclosing  box,  and  a 
glance  will  show  if  the  arrester  is  in  proper  condition  for  the 
next  storm. 


THE  ARC   DAMP   ARRESTER. 

The  Arc  Damp  lightning  arrester,  made  by  the  I1.  &  M.  Co., 
is  designed  for  either  alternating  or  direct  current  circuits. 
It  consists  of  a  porcelain  shield  or  box,  the  over-all  dimensions, 
including  binding  posts,  being :  length,  4%  in.;  width,  1  11-16 
in.  ;  height,  3  >/j  in. 

It  has  an  air  gap  of  fixed  dimensions,  in  series  with  a  disc 
or  block  of  special  composition  which  serves  to  dampen  the 


Figs.  2750-2755 


ACCESSORIES. 


393 


Fig.    2750.     The    Arc    Damp    Lightning 
P.  &  M.   Company. 


arc  in  the  air  gap  and  proven t  the  working  current  from  fol- 
lowing the  lightning  discharge  current.  The  arrester  is  in- 
i ended  for  use  on  circuits  having  a  working  voltage  of  250 
volts  or  less.  To  this  voltage  it  is  essentially  an  open  circuit, 
there  is  no  leakage  of  current  through  it  and  no  mutual  inter- 
ference of  signal  circuits.  To  a  lightning  discharge,  however, 
it  offers  a  ready  path  to  earth  at  a  voltage  we.l  below  that 
necessary  to  break  down  the  insulation  resistance  of  fairly  well 
built  magnets.  The  capacity  is  ample  for  carrying  off  the 
charge  of  ordinary  signal  circuits. 

The  area  and  length  of  the  air  gap — a  hole  punched  in 
a  sheet  of  mica — is  not  only  protected  from  outside  interference, 
but  is  essentially  sealed  against  n  renewal  of  oxygen  after 
the  arc  has  started.  This  feature-,  together  with  the  peculiar 
damping  effect  of  the  composition  block  or  disc,  makes  it 
essentially  impossible,  short  of  the  destruction  of  the  arrester 
as  a  whole,  to  fuse  together  the  brass  discs  which  form  the 
walls  of  the  air  gap. 

Lightning  trouble  has  been  experienced  with  installations 
where  distant  signals  are  controlled  without  the  use  of  line 
wires,  no  wires  being  used  except  for  the  local  circuits  at  signal 
locations.  The  most  reliable  evidence  seems  to  indicate  that 
trouble  is  caused  by  a  static  difference  of  potential  between  the 
rails  of  the  track  circuit  and  the  earth,  the  disruptive  discharge 
taking  place  through  the  track  relay,  the  signal  control  mag- 
net, and  thence  to  earth.  In  this  case  the  remedy  would  be  to 
apply  an  arrester  to  each  wire  which  connects  the  relay  coil 
to  the  track  rail.  Trouble  of  this  character  can  be  overcome 
by  the  proper  application  of  the  arrester,  the  most  difficult 
part  usually  being  in  the  correct  diagnosis  of  the  condition. 

A  common  ground  may  be  used  fcr  all  arresters  in  a  signal 
tower,  at  a  signal  location,  or  at  any  other  place  where  a 
number  of  arresters  are  bunched.  An  exception  to  this  is 
where  arresters  are  used  on  circuits  having  a  wide  difference 
of  working  voltage,  such  as  500  volts  or  over  on  the  one  hand 
and  110'  or  under  on  the  other.  The  reason  for  this  is  the  pos- 
sibility of  a  defective  ground  connection  causing  a  discharge 
from  a  circuit  of  higher  voltage  to  a  circuit  of  lower  voltage. 

If  a  ground  plate  is  desired  it  may  be  made  of  a  tinned 
copper  plate  -fa  in.  thick  by  18  in.  square,  to  which  is 
soldered  a  No.  6  B.  &  S.  gauge  tinned  copper  wire  about  10  ft. 
long.  This  plate  should  be  buried  in  a  hole  dug  deep  enough 
to  reach  permanently  moist  earth.  The  plate  should  be  sur- 
rounded by  a  liberal  quantity  of  crushed  cliarci  ai  or  coke. 
This  material  is  a  conductor  and,  being  hygroscopic.  al>> 
and  retains  moisture  and  multiplies  the  area  of  contact 
tween  the  plate  and  earth.  Engine  smoke-liox  cinders 
good  and  are  usually  convenient  for  the  purpoM-. 

Magnetic   material   such  as   iron  or   steel   should    not   be 


Fig.   2751.     Lightning-  Arresters  Applied  to   Block   Signal  Apparatus. 

as  a  part  of  the  conductor  in  securing  a  ground.  A  steel  rail, 
for  instance,  offers  mere  than  10  times  the  impedance  to  alter- 
nating current  of  60  cycles  that  it  does  to  direct  current.  Aa 
Arrester.  tne  impedance  increases  with  the  frequency,  it  is  evident  that 

a  rail  would  be  a  poor  conductor  for  a  current  having  the  very 
high  frequency  of  a  lightning  discharge. 

Connecting  to  a  piece  of  iron  pipe  driven  into  the  ground 
is  open  to  the  objection  that  the  pipe,  even  if  galvanized,  will 
soon  be  coated  with  insulating  rust,  and  the  character  of  the 
ground  into  which  it  is  driven  is  often  unknown  or  not  con- 
sidered, and  it  has  not  the  benefit  of  coke  or  charcoal. 

An   independent  ground  plate  has  the  advantage  of  being  un- 


Fig.  2753.     Carbon  "Lightning  Arrest 
ers   in    Parallel   with   Instrument   to 
be   Protected.     Railroad   Sup- 
ply  Company. 


n 

.SIGNAL  CONTROL.. 

n 

~i 

y 

L                                      LOCK 

1  1 
—  1 

—  i 

t 

Fig.   2752.      Lightning   Arresters   Applied   to 
Interlocking  Apparatus. 


Fig.   2754.     Siemens   &   Halske   Vacuum   Lightning 
Arrester.     United  States  Electric  Company. 


htning  Arrester.     Bryant  Zinc  Company. 


394 


ACCESSORIES. 


Figs.  2760-2768 


disturbed  by  changes  or  renewals  in  other  apparatus,  such  as 
would  be  the  case  were  connections  made  to  rails,  pipes,  etc. 
The  resistance  between  ground  plate  and  earth  should  not 
exceed  50  ohms. 

Fig.  2751  shows  how  lightning  arresters  of  the  arc  damp  type 
are  applied  to  protect  block  signal  apparatus ;  and  Fig.  2752 
ehows  these  arresters  applied  to  the  protection  of  interlocking 
apparatus. 

Figs.  2765-2767  show  the  details  of  the  ground  plate,  such 
as  above  mentioned.  Fig.  2788  shows  the  method  of  installing 
the  Paragon  ground  cone,  which  is  designed  as  a  substitute  for 
the  ground  plate. 


which  give  a  decided  choking  effect.  The  different  parts  of 
this  arrester  are  contained  in  separate  pockets,  cast  in  a 
solid  porcelain  block. 


G.     K.     ALTERNATING     CURRENT    ARRESTERS. 

The  spark  gap  type  arrester,  known  as  "Form  D."  consists 
of  a  row  of  metal  cylinders,  spaced  with  a  small  air  gap  be- 
tween them  and  connected  between  line  and  ground. 


PREMIER    LIGHTNING   ARRESTER. 

Figs.  2759-2760  show  the  Premier  lightning  arrester  made  by 
the  Bryant  Zinc  Co.  i 

A  carbon  ground  plate  is  placed  between  two  toothed  brass 
spark  plates,  and  two  double-wound  choke  coi's  are  used, 


Fig.    2764.      Four-Point    Choke    Coil    Light- 
ning Arrester.     Railroad  Supply 
Company. 


Fig.  2/00.     Premier  Lightning  Arrester.     Bryant  Zinc  Company 


;g  Copper  P/arfe. 


Fig.    2761.     Triple    Pole,    aoo-Volt    Lightning    Arrester. 
General  Electric  Company. 


C/rrcfe/~s  which  are  fo  foe  I 

thorougrh/y  wef  anc/  fcrrrrpea'  r 


earth. 


\     i, 
) 


Figs.  2765-2767.     Ground   Plates  and  Details. 


Fig.  2762.     Method  of  Testing  for  Resistance  of  Ground 

Connection.      (Assuming  Resistance  of   Earth 

to  be  Zero.) 


Fig.  2763.     Carborundum  Lightning  Arrester.     L.  S.  Brach 
Supply  Company. 


Fig.  2768.     Lightning  Arrester. 
General  Electric  Company. 


Figs.  2769-2774 


ACCESSORIES. 


395 


70, 1 OZ 


Fig.     2769.       Lightning     Arrester.       New    York     Central. 
Hall    Signal   Company. 


Fig.  2772.     Lightning  Arrester,  Style  "E-G."     Hall  Sig- 
nal  Company. 


Fig.  2770.     Lightning  Arresters  in   Relay   Bex. 
Signal   Company. 


Hall 


Fig.    2773.      Lightning   Arresters,    Style   "W." 
nal  Company. 


Hall    Sig- 


II.VI.L     LIGHTNING    ARRESTERS. 

Fig.  2769  shows  "NYC"  style  lightning  arrester  made  by  the 
Hall  Signal  Co. ;  Fig.  2770  shows  a  number  of  these  arresters 
as  installed  in  a  relay  box;  Fig.  2771  illustrates  the  Style  "H" 
arrester;  Fig.  2772  shows  the  style  "EG";  and  Fig.  2773  illus- 
trates the  Hall  Style  "W"  arrester. 


Fig.  2771.     Lightning  Arrester,  Style  "H." 
Company. 


Hall  Signal      Fig.  2774. 


2300- Volt   Lightn'ng   Arrester    for   Line   Serv- 
ice.     General    Electric    Company. 


396 


ACCESSORIES. 


Figs.  2775-2782 


Fig.  2775.     Style  "B"  Lightning  Arrester.     Railroad  Supply  Company. 


tig.  2778.     Style  "C"  Lightning  Arrester,  with   Fuse  Block  and  Fuse. 
Railroad    Supply   Company. 


Fig.    2776.     Enclosed    Lightning 

Arrester    Mounted  on  Slate 

Base.      Railroad  Supply 

Company. 


Fig.   2777.     Application   of 
Enclosed  Lightning  Ar- 
rester.    Railroad  Sup- 
ply   Company. 


Fig.  2779.     Style  "A"  Lightning  Arrester.     Railroad  Supply  Company. 


Fig.    2780.     Style     "F"     Arresters     in 
Series   with   Instrument  to   be   Pro- 
tected.     Railroad    Supply    Com- 
pany. 


Fig.  2781.     Bank     of     Vacuum     Arresters.       United 
States    Electric    Company. 


Fig.  2782.     Part  Sectional  View  of  Enclosed  Lightning 
Arrester.      Railroad   Supply  Company. 


Figs.  2783-2788 


ACCESSORIES. 


397 


PARAGON"    GROUND   CONE. 

The  Paragon  ground  cone  is  a  grounding  device  made  by  the 
Paragon  Sellers  Co.  which  consists  of  a  hollow  perforated  cone 
of  pure  copper  filled  with  charcoal  or  coke.  The  charcoal  or 


*>•  m 


SO  Note  B&S.  Gage  Soft  Dra 
Cooper  Hire  Tinned. 


p 

( 

J 
jl 

_ 

Jt 

?—  -  i 

i 
i 
i 
i 

jlr—-. 

r.J              U 

_j 
fl 

,  , 
I          <, 

-4- 
_  Jn 

fiber  D/s/f 


Fig.  2786.   Details  of  Lightning  Arrester.     Federal  Signal 
Company. 

coke  constantly  attracts  moisture,  keeping  the  earth  damp 
around  the  cone,  and  the  perforations — 75  to  tlie  sq.  In. — 
furnish  an  ample  number  of  discharge  points. 

The   cone   is   easily    installed,   as    it    is   only  necessary   to   bore 
a    post    hole    and    <ln>]>    the    <•<  no    in. 


ng.    2783.     Style    "F"    Lightning    Arrester.      Railroad 
Supply  Company. 


Fig.  2787.     Paragon  Ground  Cone. 
Paragon  Sellers   Company. 


Fig.  2784.     Details  of  Style  "F"   Lightning  Arrester.     Railroad   Supply 

Company. 


Fig.  2785.     Cast   Iron   Box,  with   Slate   Base  for  Enclosed   Lightning 
Arresters.      Railroad    Supply    Company. 


Fig.  2788.  Method  of  Installing  Par- 
agon   Ground    Cone.     Paragon 
Sellers    Company. 


398 


ACCESSORIES. 


Figs.  2789-2792 


LOCKS 


ELECTRIC  LOCKS 


Fig.    2789.     Cross    Sectional    View    of 
Electric  Lock.     Fig.   2792. 


Figs.  2789-2700  show  an  electric  lock  applied  to  a  Saxby  & 
Farmer  interlocking  machine.  D  is  the  rotating  locking  shaft 
operated  by  the  lever  latch.  Arm  and  link  F  are  connected  to- 
segment  A  mounted  on  a  shaft  in  the  lock.  The  edge  of  this 
segment  is  notched,  according  to  the  locking  desired,  to  engage 
the  dog  on  B,  connected  by  a  bar  fastened  to  the  armature  of 
the  electromagnet  K,  and  so  pivoted  that  the  energizing  of  the 
magnet  E  will  raise  dog  on  B  out  of  the  notch.  An  indicator 
is  provided  to  show  when  unlocked  ;  a  circuit  controller  oper- 
ated by  the  magnet  and  circuit  controller  operated  by  shaft  are 
included  in  the  mechanism  for  making  or  breaking  circuits 
controlled  by  the  lever  or  lock.  The  bar  F  may  also  be  attached 
to  the  tappet  of  an  interlocking  machine  which  has  vertical 
locking. 


Names  of  Parts  of  Electric  Lock;  Fig.  2792. 

1  Intermediate  Bracket   4     C.  R.  Steel  Turned  I'in 

2  Connecting  Arm  5     Angle  Iron 

3  Tap  Bolt  6    Bolt  for  i  and  5 


Fig.    2790.      Sectional   View    of   Electric    Lock,    Fig.    2792. 

Showing  Alternative   Method  of  Attaching  to 

Saxby  &  Farmer  Interlocking  Machine. 


Fig.  2791.     Model  7  Electric  Lock  Applied  to  a  Stand- 
ard   Interlocking  Machine. 


3  2 
324 

Fig.  2792.     Electric  Lock  Applied  to  Saxby  &  Farmer  Interlocking  Machine. 


Figs.  2793-2796 


ACCESSORIES. 


399 


Fig.   2794.     Model   2,    Electric   Lock  Applied  to   Saxby 

&   Farmer   Interlocking  Machine.     The   Union 

Switch     &    Signal     Company. 


Names  of  Parts  of  Model  2 
Electric    Lock    Applied    to 
Saxby     &     Farmer     In- 
terlocking   Machine. 
Fig.    2794. 

6  Dog   {Mechanical  Locking) 

7  Locking  Bar 

9     Supporting  Plate 

1 6  Rivet  for  24 

17  Rivet  for  25 

24  Guard  Plate 

25  Locking  Dog 


Fig.    2793.     Style    "B"    Electric    Lock    Applied    to    Standard    Interlocking 
Machine.     General   Railway   Signal   Company. 


Fig.    2795.     Application    of    Style    "B"    Electric    Lock 

to    Saxb'r    &    Farmer     Interlocking     Machine. 

General     Railway    Signal     Company. 


Fig.  2796.     Style  "D"  Electric  Lock  Applied  to  Dwarf 

Interlocking    Machine.      General     Railway 

Signal    Company. 


400 


ACCESSORIES. 


Figs.  2797-2804 


Figs.     2797-2800.       Electric     Lock     for     Mechanical     In- 
terlocking   Machines.      The    Union    Switch 
&    Signal    Company. 


rcgr, 


Figs.    2801-2802.      Union    Electric    Lock    Applied    to    Im- 
proved Saxby  &  Farmer  Interlocking  Machine. 


Fig.  2803.     Model  "F"  Electric  Lock  Applied  to  Saxby 

&  Farmer   Interlocking  Machine.     General 

Railway  Signal  Company. 


Names    of    Parts    of    Model    7  Electric    Lock    Applied    to 
No.      2      Johnson     Machine;       Fig.     2804. 

1  Tappet 

2  Bar 

3  Dog 

4  Filler 

5  Plate 

6  Flat  Head  Machine  Screw 

7  Rivet,   Countersunk   Head 

8  Supporting    Bracket 

9  Plunger 

10  Crank 

11  Pivot  Pin  and  Cotter 

12  Turned  Pin  and  Cotter 

13  Washer 

14  Tap  Bolt 

15, 150  Machine  Bolts 


Fig.  2804.     Model  7  Electric  Lock  Applied  to  Johnson  No.  2  Interlocking  Machine.    The  Union  Switch  &  Signal. 

Company. 


Figs.  2805-2812 


ACCESSORIES. 


401 


Names  of  Parts  of  Model  i  Elec- 
tric Lock  Applied  to  Saxby  & 
Farmer    Interlocking    Ma- 
chine;  Fig.   2810. 

Slotted   Sheet  Iron  Plate 

Locking  Lever 

Fulcrum  Bracket 

C.  R.  S.  Dog 

Flat  Head  Rivet 

Flat  Head  Screzv,  Fastening  to  7 

Tap  Bolts 


3 

5 

7 

13 

18 

19 
23 


Figs.    2808-2809.       Electric    Lock    Applied    to 

Mechanical   Interlocking  Machine.     Union 

Switch   &  Signal  Company. 


Names  of  Parts  of  Model  i   Elec- 
tric   Lock   Applied  to   a  Stev- 
ens   Interlocking    Machine; 
Figs.   2811-2812. 

3  Slotted  Sheet  Iron  Plate 

4  Locking  Lever 

11  Right-Hand  Supporting  Strip 

12  Left-Hand   Supporting   Strip 

14  C.  R.  S.  Dog 

15  Filler 

18  Flat  Head   Rivet  for  Fastening 

19  to  Tappet 

19  C.  R.  S.  Dog 

20  Tap  Bolts  for  n  and  12 

21  Flat  Head   Rivet   for  Fastening 

14  to  Tappet 

23  Tap  Bolt  for  Fastening'  Frame 
to  ii  and  12 

39  Flat  Head  Machine  Screw  for 
Fastening  ii  and  12  to  Ma- 
chine. 


Figs.  2805-2807.     Electric  Lock  Covered;  Cover  Removed, 
Segment    Engaged    by    Dog;    Dog    Raised,    Seg- 
ment   Released.       General     Railway    Sig- 
nal   Company. 


Fig.    2810.     Model     i     Electric     Lock 
Applied   to   Saxby   &  Farmer   In- 
terlocking     Machine.        The 
Union     Switch     &    Signal 
Company. 


Figs.  2811-2812.     Model   i    Electric   Lock   Applied  to   Stevens  Interlocking   Machine. 


402 


ACCESSORIES. 


Figs.  2813-2817 


ELECTRIC  SWITCH  LOCKS 


G.     R.     S.     ELECTRIC     SWITCH     LOCK. 

In  Figs.  2816-2817  are  shown  a  switch  lock  made  by  the 
General  Railway  Signal  Company  applied  to  a  switch  and  a 
control  circuit  for  operating  it.  The  switch  lock  consists 
primarily  of  a  weighted  vertical  plunger,  designed  to  pass, 
through  a  hole  in  the  switch  lock  rod,  actuated  by  a  hand 
lever.  On  the  same  shaft  with  the  lever  Is  a  notched  quadrant 
so  arranged  that  a  dog  attached  to  the  armature  of  an  electro- 
magnet will  drop  into  the  notch  and  hold  the  apparatus  im- 
movable when  the  magnet  is  de-energized  and  the  plunger  down. 
A  small  semaphore  indicator  is  provided  to  give  visual  Indica- 
tion of  the  condition  of  the  magnet.  The  whole  is  mounted  in 
an  iron  box  set  on  an  iron  post. 

Fig.  2815  illustrates  a  further  development  of  the  switch  lock 
shown  in  Figs.  2816-2817.  Here  a  telephone  is  added  mounted  in 
a  box  above  the  switch  lock  so  that  trainmen  may  communicate 
with  the  operator,  who  controls  the  lock  and  who  has  a  tele- 
phone in  his  office  connected  to  the  one  at  the  switch. 

The  electric  switch  lock  shown  in  Fig.  2818-2819  consists  of 
an  electro-magnet  having  two  front  and  two  back  contacts. 
When  the  magnet  is  energized,  a  locking  dog  is  lifted  from  a 
notch  in  the  plunger,  allowing  the  switch  to  be  thrown.  The 
movement  of.  the  plunger  operates  a  three-way  circuit  con- 
troller. When  the  magnet  is  de-energized,  the  dog  falls  by 
gravity,  and  locks  the  switch  in  the  desired  position  by  engag- 
ing with  the  notch  of  the  plunger. 


t-4       r--y 

* 

L        \ 

i     /.  C 

i 

Loc/r. 

— 

-LererA/o.3 
/-cr 

/-b 

• 

Z-o 

Common 

Fig.  2813.     Circuits  for  Outlying  Electric  Switch  Lock 
at   Block  Station.     Erie   Railroad. 


Fig.        2814.     Circuit        for       Electric 
Switch    Lock.      General    Rail- 


frffri 

way    Company.                                         phone.      General 

Railway    Si 

nal    Company. 

p, 

u      1=                                                              .  n^.g^dgP" 

Figs.   2816-2817.     Electric    Switch   Lock  in   Place.     General    Railway   Signal    Company. 


Figs.  2818-2823 


ACCESSORIES. 


403 


Parts,    Electric    Switch 
Lock;    Figs.    2818-2819. 


Figs.    2818-2819.     Electric    Switch    Lock. 

A     Armature  Lever  and  Latch  Dog 

B     Armature 

C     Circuit  Controller  Arm 


D    Roller 

E    Front  Contact  Arm 

F    Back  Contact  Arm 


1    i         —  r 

!   ! 

—|  1 

_- IT" 


Figs.  2820-2822.     Electric   Switch    Lock.     American   Railway   Signal   Company. 


240  Ohms 


TDWFR. 


E    /OVo/t  battery. 


NOTE. 

Indicator  Needle  at  a   =  Switch  unlocked. 

"  "    b   =  Lock  door  open. 

"  "    c  =  Switch   locked   in  normal   position. 

"  "    d   =  Something  out  of  order 

"  "    o   =  Something  out  of  order. 


f    =   Contact,  operated  by  lock  door,  made  when  door  is  open, 
g  =   Contact,  operated  by  leek  handle,  broken  when  switch  is 
unlocked. 


p-         _o^-       r*-        •*.       r          TTI      j.  •       o     -i  L     T       1          •<.!  h   —   Contact,   operated   by  lock   handle,  made  when  switch   is 

rig.    2823.     Circuits    for    Electric    Switch     Lock    with 


Repeater.      General    Railway    Signal    Company. 


unlocked. 

k   =   Back-contact  on  lock  armature. 


404 


ACCESSORIES. 


Figs.  2824-2830 


Fig.  2824.     Circuits  for  Electric  Switch  Lock 
with  Telephone.     (See  Fig.  2815.) 


Figs.    2825-2826.     Electric      Switch 

Locks.      Railroad    Supply 

Company. 


Fig.    2827.      Electric    Switch     Lock.      American 
Railway  Signal  Company. 


Fig.  2828.     Application  of  Electric  Locks  to  Switch  Point 

(.Lock  can  also  be  applied  to  the  Head  Rod.) 

Railroad    Supply    Company. 


Figs.  2829-2830.     Style  "F"   Switch  Lock.     Hall  Signal  Company. 


Figs.  2831-2834 


ACCESSORIES. 


405 


MECHANICAL  TIME  LOCKS  AND  TIME  RELEASES 


MECHANICAL    TIME    LOCKS. 

Mechanical  time  locks  are  employed  with  interlocking 
machines  to  introduce  a  time  element  between  placing  signal  or 
other  levers  normal,  and  any  change  in  the  route  for  which  the 
signal  or  other  function  was  reversed.  They  are  used  instead 
of  electrical  track  circuit  approach  locking  and  are  operative 
for  every  movement  of  the  signal  or  other  lever. 

Fig.  2840  shows  the  mechanical  time  lock  made  by  the  Union 
Switch  &  Signal  Company.  The  contact  of  the  lever  locking  Is 
secured  by  engagement  with  an  extra  piece  of  cross  locking 
driven  by  a  bar  in  the  time  lock  vertically  moved  as  the  lever 
is  reversed.  A  rack  on  this  bar  engages  a  gear  wheel  con- 
nected to  a  ratchet  and  escapement  in  such  a  manner  as  to  per- 
mit a  quick  movement  of  the  lever  to  the  reversed  position  to 


Fig.        2831.      Mechanical         Time 
Lock    Applied    to     National     In- 
terlocking     Machine.  The 
Union     Switch     &     Signal 
Company. 


Figs.    2832-2833.     Mechanical    Time    Lock    Applied    to 

Standard    Interlocking   Machine.      The     Union 

Switch    &    Signal    Company. 


Names  of  Parts,  Mechan- 
ical  Time    Lock    Ap- 
plied    to      National 
Interlocking     Ma- 
chine; Fig.  2831. 

1  Operating    Rod    with 

Jaw. 

2  Lever 

3  Stud 

4  Pin  and  Cotter 

5  Locking  Bar 

6  Guide 

7  Bracket 

8  Bracket  for  Supporting  5 

9  Cross  Locking 

10  Bolt 

11  Cross  Locking  Dog 

12  Cap  Screzv 

13  Pin  and  Cotter 


o 


'o 


Fig.   2834.     Mechanical   Time  Lock   Applied  to   Saxby  &  Farmer   In- 
terlocking Machine.     The  Union  Switch  &  Signal  Company. 


406 


ACCESSORIES. 


Figs.  2835-2842 


Fig.  2835.     Electro  Mechanical  Hand  Screw  Release  Ap- 
plied to  Electric  Interlocking  Machine.     General 
Railway  Signal  Company. 

lock  the  switch  levers  but  requiring  a  slow  movement  consum- 
ing one  minute  or  more  to  place  the  lever  normal,  lower  the 
bar  and  release  the  switch  locking. 


TIME    RELEASES. 

Slow  hand  or  time  releases  are  employed  in  connection  with 
electric  locks  on  interlocking  machines  to  release  mechanically 
the  electric  locks  after  an  operation.  They  require  from  20 
seconds  to  two  minutes  to  operate.  The  operation  may  also 
mechanically  lock  certain  levers  so  as  to  insure  the  return  of 
the  device  to  the  normal  position  to  unlock  such  levers.  Hand 
releases  are  usually  employed  at  an  interlocking  plant  having 
approach  locking,  to  release  such  locking  in  case  of  emergency 
when  it  has  become  effective  because  of  the  approach  of  a 
train  and  a  change  of  route  is  necessary. 

The  hand  screw  release,  Figs.  2843-2845,  is  made  by  the 
<Jeneral  Railway  Signal  Company.  Circuits  may  be  controlled 
by  this  device.  When  the  apparatus  is  normal  the  crosshead 
is  at  the  extreme  left  hand  end  at  screw  L.  When  in  this 
position  insulated  pin  II  has  forced  the  left  hand  center  con- 


Figs.  2836-2838.    Universal  Hand  Screw  Re- 
lease for  Mechanical  Interlocking  Ma- 
chines.   General    Railway    Sig- 
nal   Company. 


Fig.  2839.     Application   of   Universal    Hand   Screw  Re- 
lease to  Saxby  &  Farmer  Interlocking  Machine. 
General    Railway  Signal    Company. 


Figs.  2840-2842.    Mechanical  Time 

Lock.     The  Union  Switch   & 

Signal   Company. 


Figs.  2843-2848 


ACCESSORIES. 


407 


tact  0  against  the  side  contact  spring  N  and  the  head  of  O 
will  be  held  by  the  nofth  in  retaining  spring  P.  It  cannot  slip 
out  of  this  notch  and  break  the  circuit  until  H  strikes  against 
the  end  of  P,  thereby  raising  it.  When  the  apparatus  is  in  the 
full  reverse  position  the  right  hand  set  of  contact  springs  is 
operated  in  the  same  manner  by  H.  Thus,  it  is  necessary  to 
operate  the  device  through  its  full  stroke  forward  and  back  in 
order  to  accomplish  a  release  and  restore  the  circuits.  As  the 
center  contact  springs  O  snap  from  their  extreme  positions  a 
quick  break  is  accomplished  avoiding  an  arc. 

Figs.  2846-2847  show  the  application  of  a  mechanical  screw 
release  to  an  interlocking  machine  with  vertical  locking.  The 
release  actuates  an  extra  tappet  carrying  a  special  dog  which 
drives  a  piece  of  cross  locking.  This  piece  of  cross  locking  is 
provided  with  a  wedge  which  enters  the  lock  box  and  raises  the 


dog  in  the  lock  from  engagement  with  the  locking  of  the 
machine.  The  piece  of  cross  locking  will  butt  against  and  hold 
all  the  locking  having  to  do  with  the  tappet  on  which  the 
lock  acts  when  the  screw  release  is  reversed,  thereby  holding  the 
route  locked  until  the  release  has  been  returned  to  its  normal 
position. 

In  Fig.  2855  is  shown  an  application  of  an  electrical  time 
circuit  breaker  (Figs.  2849-2852)  used  to  introduce  a  time 
element  in  releasing  the  route  locking  of  an  interlocking  plant. 
The  time  circuit  breaker  is  an  electrical  device  which  will  make 
or  break  one  or  more  circuits  a  predetermined  number  of 
minutes  after  it  has  been  put  in  action.  Reversal  of  any  one 
of  the  signal  levers  opens  circuit  breaker  L  and  de-energizes 
relay  B.  This  opens  the  circuit  of  lock  C  which  passes  from 
battery  E  through  contact  of  B,  wire  J,  contact  of  A,  to  term- 
inal O,  through  contact  of  time  circuit  breaker,  terminal  M, 
floor  push  D,  lock  C  to  battery.  Relay  B  is  a  stick  relay  and 


2843-     Electrical    Screw    Hand    Release. 
Railway   Signal  Company. 


General 


Figs.  2844-2845.     Electrical  Screw  Hand  Release.     Gen- 
eral Railway  Signal  Company. 


Names  of  Parts,  Screw  Hand  Release;  Figs.  2844-2845. 

A  Insulating  Block 

B  Pinion  Shaft  with  Handle 

C  Crosshead  Insulator 

D  Crosshead 

E  Gear  Wheel 

F  Collar 

G  Contact  Post  Insulator 

H  Pin 

K  Bad;  Sleeve 

L  Operating  Screw 

M  Frame 

N  Side  Contact  Spring 

O  Center  Contact  Spring 

P  Retaining  Spring 

Q  Binding  Posts 


Figs.  2846-2847.     Mechanical  Screw  Hand   Release  Applied   to  An 

Interlocking  Machine  with  Vertical  Locking.     General 

Railway  Signal  Company. 


Fig.    2848.      Electro-Mechanical    Hand    Screw 

Release.     General  Railway  Signal 

Company 


408 


ACCESSORIES. 


Figs.  2849-2852 


cannot  again  pick  up  until  relay  A  is  de-energized,  owing  to  the 
presence  of  a  train  on  the  track  circuit  with  all  signal  levers 
normal  or  until  the  time  release  has  acted.  When  relay  A  is 
de-energized  it  restores  B  through  a  back  point  but  keeps  the 
circuit  for  lock  C  open.  Relay  A  is  also  a  stick  relay  and  can- 
not pick  np  until  I!  is  energized.  If  the  wrong  route  has  been 


6I-I& 


the  emergency  release,  Figs.  2853  and  2857,  made  by  the  Union 
Switch  &  Signal  Company,  is  as  follows: 

The  signal  lever  being  normal,  the  handle  is  turned  to  lock 
the  signal  lever  normal  mechanically  and  release  the  electric 
lock  on  the  switch  lever  mechanically.  The  switch  lever  can 
now  be  reversed.  Reversal  of  the  direction  of  rotation  of  the 
handle  restores  the  device  to  its  normal  position,  thus  releasing 
the  signal  lever  from  this  special  mechanical  locking.  If  the 
electric  locks  are  on  the  signal  levers  the  switch  levers  are 
locked  during  an  operation.  The  time  required  for  an  niicrntion 
depends  upon  the  apparatus  and  adjustment  provided.  The 
slow  speed  apparatus  consists  of  gearing,  in  the  circular  case, 
turned  by  the  wheel  and  handle  to  drive  a  special  locking  bar 
as  shown  in  Fig.  2854.  which  represents  the  electric  lock 
and  the  special  releasing  arrangement  underneath.  The  lock- 
ing bar  is  connected  by  a  lug  1,  and  link  2,  to  the  slotted  bar  4. 
engaging  with  the  rod  5,  in  such  a  manner  as  to  operate 
mechanically  the  armature  of  the  electric  lock,  raise  the  locking 
dog  and  release  the  lock.  Fig.  2854  shows  the  lock  released 
and  the  locking  bar  in  its  full  reversed  position.  This  locking 
bar  in  any  other  than  its  normal  position  mechanically  locks 
the  signal  lever  normal  through  the  cross  locking. 

The  devices  in  Fig.  2853,  made  by  the  Union  Switch  &  Signal 
Company,  perform  the  same  function  electrically  as  the  releases 
already  described,  by  closing  normally  open  circuit  controllers, 
in  the  rectangular  boxes,  shown  with  covers  removed,  thereby 
affecting  the  lock  circuit.  To  insure  its  return  to  the  normal 
position  other  circuit  controllers,  normally  closed,  affecting  the 
control  or  locking  of  the  signals  are  opened  to  prevent  the 
I  clearing  of  the  signals  during  the  operation  of  the  release.  This 
may  also  be  arranged  to  lock  conflicting  levers  mechanically. 


Front  View. 


661-4 


Back    Contact   Closed,    Front 
Contact  Open. 


Front  Contact  Closed,    Back 
Contact  Open. 


Rear  View. 
Figs.  2849-2852.     Electrical  Time  Circuit  Breaker  and  Contacts.     Railroad  Supply  Company. 


lined  up  and  it  is  necesary  to  restore  the  functions  to  normal 
without  being  released  by  a  train,  the  signalman  presses  the 
strap-key  which  puts  the  time  circuit  breaker  in  operation. 
After  the  proper  interval  of  time  contacts  N  and  P  are  brought 
together  and  relay  B  is  energized  thereby,  but  at  the  same 
time  contacts  M  and  O  are  opened,  thereby  keeping  lock  C  de- 
energized  until  the  time  circuit  breaker  has  ceased  to  act. 

With  the  electric  locks  on  the  switch    levers  the  operation  of 


The  electric  lock  shown  in  this  illustration  is  not  connected, 
except  electrically,  with  the  hand  releases.  In  this  arrange- 
ment the  hand  wheel,  through  gearing,  slowly  moves  the  flat 
bar  leading  into  the  circuit  controller  box.  To  this  bar  is 
attached  a  contact  plate  engaging  springs  in  such  a  manner  as 
tt»  open  and  close  contacts  as  described.  The  circuit  controller 
box  is  the  same  as  that  employed  in  the  electro-pneumatic  sys- 
tem for  indication  boxes  at  switches. 


Figs.  2853-2856 


ACCESSORIES. 


409 


jX53.     Model  2  Electric  Hand  Release  Applied  to  Saxby  &  Farmer 
Interlocking  Machine.     The  Union  Switch  &  Signal  Company. 


Fig.  2854.     Releasing  Attachment  for  Model  2  Electric 
Lock  Applied  to  a  Saxby  &  Farmer  Interlock- 
ing Machine.     The  Union   Switch   & 
Signal  Company. 


Names    of    Parts,    Releasing    Attachment   for    Model   2 

Electric  Lock  Applied  to  a   Saxby   &   Farmer 

Interlocking    Machine;    Fig.    2854. 

1  Lug  5  Brass   Operating  Rod 

2  Adjustable   Link  6  Brass  Bushing 

3  Motion  Plate  Guide  7  Spring 

4  Motion  Plate 


Names  of  Parts,  Route- 
Locking  Circuits  with 
Electrical  Time 
Circuit     Breaker; 
Fig.  2855. 

A     Track  Relay 

B     Control  Relay 

C     Electric  Lock 

D     Floor  Push 

E     Main   Battery 

F     Track  Battery 

G  Operating  Terminal 
,»H  Time  Circuit 
Breaker 

J      Wire 

K  Operating  Terminal 
in  Time  Circuit 
Breaker 

L  Circuit  Breaker  Op- 
crated  by  Signal 
Levers 

M    Contact 

O     Contact  Arm 

R     Track  Relay  Lead 

S     Track  Relay  Lead 

T     Wire 


TIME   CIRCUIT   BREAK  tR 


Fij 


2856.     Wall    Type    Hand     Screw     Release     Circuit 
Controller  with  Cover  Removed.     The  Union 
Switch    &    Signal    Company. 


Fig.  2855.     Electrical  Time  Circuit 
Breaker  Used  as  Time  Release 
for  Route  Locking  Circuits. 
Railroad    Supply    Com- 
pany. 

Figs.  2856  shows  another  type  of  instrument  made  by  the 
Union  Switch  &  Signal  Company,  designed  to  accomplish  the 
same  result  as  those  above  described  by  a  semi-electrical 
method.  It  is  used  principally  with  power  interlockings  where 
it  may  be  placed  at  any  desired  point  in  the  tower.  A  gear 
wheel  is  driven  by  a  worm  gear  on  a  shaft  to  which  is  con- 
nected the  hand  wheel.  The  movement  of  the  gear  wheel  can 
be  arranged  to  open  or  close  one  or  more  contacts  as  desired  to 
affect  the  control  of  signals  and  locks  and  require  the  return 
to  its  normal  position.  Provision  is  made  for  controlling  the 
high  voltage  currents  employed  in  electric  interlocking  by  having 
contacts  of  a  slightly  different  construction.  A  brake  is  also 
provided  so  as  to  prevent  false  movements  from  affecting  the 
contacts.  An  indicator  can  be  furnished  to  show  the  position 
of  the  apparatus,  while  the  cams  driven  by  the  gear  wheel  con- 
trol the  contacts  in  such  a  manner  as  to  provide  for  always 
turning  the  handle  in  the  same  direction  for  restoring  as  for 
setting,  giving,  if  desired,  a  long  time  interval  for  releasing  the 
locks  and  a  very  short  interval  for  returning  to  the  normal 
position. 


410 


ACCESSORIES. 


Figs.  2857-2859 


CLOCKWORK     TIME    RELEASE. 

The  clockwork  time  release  shown  in  Figs.  2858-2859  is  do- 
signed  for  the  same  purposes  as  the  hand  release,  but  unlike 
the  latter  does  not  require  the  continued  manipulation  of  the 
instrument  by  the  operator  for  the  entire  time  interval.  This 


The  instrument  is  made  in  two  forms;  one  in  which  the 
pointer  stands  normally  at  whatever  time  interval  it  is  desired 
to  secure,  and  the  other  in  which  the  knob  and  pointer  are 
latched  at  zero.  In  the  former  type  the  operator  merely  turns 
the  knob  to  zero  and  releases  it,  permitting  the  clockwork  to 


Fig.  2857.     Model  2  Mechanical  Hand  Release  Applied  to  a  Saxby  &  Farmer  Interlock- 
ing  Machine.      The   Union    Switch    &   Signal   Company. 


leaves  him  free  to  perform  his  other  duties  after  merely  turn- 
Ing  the  knob  to  the  right  against  the  stop  and  permitting  it  to 
return  slowly  to  the  time  desired  by  means  of  the  clockwork 
mechanism. 

The  maximum  time  interval  which  can  be  secured  on  this 
Instrument  is  four  minutes,  and  the  design  is  such  that  the 
Interval  can  be  varied  to  any  time  between  that  amount  and 
zero  by  the  adjustment  of  stops  in  the  instrument. 


restore  it  to  the  time  desired.  In  the  second  type  the  operator 
after  turning  the  knob  to  /ero  gives  a  small  movement  to  the 
left  to  release  the  latch,  when  it  will  automatically  return  to 
the  lime  desired.  In  neither  type,  however,  is  the  operator 
able,  by  turning  the  knob  to  the  left,  to  vary  the  time  required 
to  effect  the  release. 

It    will    be  noticed    from    the   foregoing  that   the    second   type 
of  release  equipped  with  a  retaining  pawl  or  latch  can  be  used 


Figs.   2858-2859.     Clock   Work  Time   Release.     The   Union   Switch   &  Signal   Company. 


As  will  be  noticed,  a  graduated  dial  and  clock  hand  are  pro- 
vided so  as  to  indicate  at  all  times  the  length  of  time  which 
has  elapsed  since  releasing  the  knob.  Provision  is  made  in  the 
Instrument  for  the  control  of  four  independent  circuits,  two  at 
the  zero  or  extreme  right-hand  position  of  the  pointer  and  two 
at  whatever  time  it  may  be  set  for.  The  turning  of  the  knob 
to  the  right  winds  up  the  clock  mechanism  a  sufficient  amount 
always  to  bring  the  pointer  back  to  the  rime  for  which  it  is  de- 
sired to  set  the  mechanism  after  the  knob  is  released. 


for  the  same  purposes  as  the  type  without  such  an  attachment, 
since  the  operator  can,  after  turning  his  knob  as  far  as  It  will 
go  to  the  right,  give  it  the  s.ight  left  hand  turn,  which  is 
necessary  to  release  the  retaining  pawl  and  allow  it  to  return, 
— in  practically  one  operation. 

In  addition  to  hand  operation,  this  release  can  be  operated 
by  the  lever  of  any  type  of  interlocking  machine  by  substituting 
an  attachment  in  place  of  the  knob  and  omitting  the  retaining 
latch  entirely. 


Figs.  2860-2864 


ACCESSORIES. 


411 


POWER  GENERATION  AND  DISTRIBUTION 

POWER  UNITS  AND  DYNAMO  MACHINERY 


2860.     Generator   Type    CVC. 
General    Electric    Company. 


Fig    2861.     Single-Unit   A.C.-D.C. 

Motor    Generator    Set.     Type  MIC  Motor.     General  Electric  Company. 


Fig.    2862.      Single-Unit    D.C.-iJ.C.    Motor    Generator    Set,    Type  MCC.     General  Electric  Company. 


Fig.  2863.     Two-Unit  Motor  Generator  Set.     General 
Electric    Company. 


Fig.  2864.  Generator.  General  Railway  Signal  Company. 


412 


ACCESSORIES. 


Figs.  2865-2870 


Fig.     2865.       Motor     Generator 
for  Sub-Station  Electric  Zone. 
New    York    Central. 


GASOLINE        ELECTRIC        GE.N'EUATuIl 
SETS. 

The  General  Electric  Co.  builds 
gasoline-electric  generating  sets 
for  signal  service  in  1,  3,  5,  10 
and  25  k.  v.  a.  sizes  for  both 
direct  and  alternating  current 
circuits,  one,  two  or  three-phase. 
25  or  60  cycles  and  in  standard 
voltages.  The  larger  a.  c.  sets 
are  designed  with  two  fly-wheels, 
which  feature  assures  more  even 
operation,  enabling  sets  to  be  op- 
erated in  parallel,  (see  Fig.  2867). 

The  General  Electric  Co.  also 
makes;  a  line  of  small  direct-con- 
nected, steam-driven  generating 
sets,  ranging  in  size  from  Z\i, 
k.  w.  upwards.  They  are  fur- 
nished in  single  or  tandem  com- 
pound types,  condensing  or  non- 
condensing,  and  with  either 
gravity  or  forced  system  of  lu- 
brication. These  were  designed 
originally  to  meet  the  severe  con- 
ditions of  marine  work,  which 
demands  a  light,  compact,  dur 
able  set,  capable  of  close  regula- 
tion and  quiet  operation,  and  ni-" 
well  adapted  for  the  operation 
of  signal  systems. 


Fig.  2866.      I.   H.   C.  "Famous  Mount- 
ing"    Engine — Hopper    Cooled — 2[j 
to  8-H    P. 


Fig.  2867.     I.   H.  C.  Victor- Engine- 
Hopper    Cooled — 2l/2    to 
8-H.  P. 


Fig-.  2868.     I.  H.  C.  Victor  Horizontal 
Engine — 4  to  25-H.   P. 


Figs.  2866-2869. 


Fig.  2869.     I.  H.  C.  "Famous   Mount- 
ing" Engine — Tank   Cooled — 4  to 

20-H.    P. 

Gasoline   Engines   for   Generators.     International   Harvester 
Company. 


Fig.  2870.  1-3-5-10  and  25  K.  W.  Direct  Connected  Gasoline  Electric  Generating  Sets.     General  Electric  Company. 


Figs.  2871-2876 


ACCESSORIES. 


Fig.  2871.     Generator.     Fairbanks,  Morse  & 
Company. 


Fig.  2872.     Motor  Generator  Set.     Two  Bear- 
ing Type.     150  H.  P.,  750  P.  M.,  3  Phase, 
50  Cycle  Motor  and  100  K.  W., 
2;o    Volt  Generator. 


Fig.  2873.     Three   Bearing   Motor   Generator  Set   Con- 
verting  Three-Phase    Alternating    Current 
into  115  Volts  Direct  Current. 


Fig.  2874.     50  H.  P.  Type  "RE"  Fair^ 

banks-Morse    Oil     Engine    Direct 

Connected   to   Direct    Current 

Generator. 


Fig.   2875.      6   H.    P.    Special    Electric 

Oil   Engine,   Direct  Connected   to 

Fairbanks-Morse    Dynamo. 


Fig.  2876.     Fairbanks-Morse  Direct  Current  Generator  Farts. 


414 


ACCESSORIES. 


Figs.  2877-2881 


Fig.  2877.     15  H.  P.  Fairbanks-Morse  Oil  Engine. 


M 


B 


m 

Fig.  2878. 


Showing  Oil  Fngine  Fittings  for  Oil  Start. 
Fairbanks,  Morse  &  Co. 


Fig.  2880.     Sectional  View — Fairbanks,  Morse  Vertical 
Gas  and  Gasoline   Engine. 

Names  of  Parts  of  Vertical  Gas  En- 
gine.    Fig.  2880. 

Cylinder         g         Cylinder  Head 
Base  isE     Flywheel 

Base  Cap      36        Lower  Base 
Suction  Valve  Spring 
Exhaust  Valve  Spring 
Exhaust   Rocker   Lever   Bracket 
Exhaust  Rocker  Fulcrum 
Exhaust  Rod 
Exhaust  Rocker  Lever 
Exhaust  Rod  End  Jaw 
Exhaust  Rod  End  Pin 
Igniter  Rftd 
Governor  Gear 
Fuel  Pump  Link  Spring 
Link  and  Lever  Pin  and  Cotters 
Fuel  Pump  Lcvei- 
Fuel  Pump  Link 
Plunger  Pin  and  Cotters 
Fuel  Pump  Plunger 
Fuel  Pump  Barrel  Cap 
Fuel  Pump  Barrel 
Valve   Chamber 
Valve  Chamber  Cap 


Fig.   2879.     I.    H.    C.   Two-Cylinder  Vertical    Stationary    En- 
gine Regulated  to  2  Per  Cent  Speed  Variation.     24  and  35 
H.   P.     International    Harvester   Comnanv. 


Fig.  2881.  Showing  Oil   Engine  Fittings  to 

Start   on    Gasoline  and  Run   on   Oil. 

Fairbanks,   Morse   &  Co. 


Figs.  2882-2886 


ACCESSORIES. 


415 


Fig.    2884.      lo-KW.      D.    C.     Generator     Direct     Con- 
nected to  Single  Cylinder  Gravity  Lubrication 
Engine.    General    Electric    Company. 


Fig.  2882.  D.  C.  Generator  Direct  Connected  to  a  Singh 
Cylinder  Engine   Having  a  Gravity  System  of 
Lubrication.     General  Electric  Com- 
pany. 


Fig.  2883.     I5-K.  W.  Direct  Current  Steam  Turbine  Set. 
Genera;    Electric   Company. 


Fig.    2885.      50-KVA,     A.     C.     Generator    with     Single 

Cylinder   Form   "K"   Engine.     Gravity   System 

of    Lubrication.      General    Electric 

Company. 


Fig.  2886.  Direct  Con- 
nected Steam  Turbine 
Generating  Set.  Gen- 
eral Electric  Company. 


416 


ACCESSORIES. 


Figs-.  2887-2889 


Fig.    2887.    ^Switchboard     and     Motor 
Boston    Elevated. 


Generator     Set. 


C.   &   N.    W.    TERMINAL    POWER    SYSTEM. 

In  the  power  distributing  system  on  the  Chicago  &  North-West- 
ern passenger  terminal  in  Chicago  power  for  all  uses  except  the 


Fig.  2888.     Motor  Generator  Sets  in  Interlocking  Plant, 
Chicago  Terminal.     Chicago  &  North-Western. 

operation  of  one  of  the  five  plants  is  taken  from  the  power 
house  at  6,600  volts,  three  phase,  and  distributed  through  a 
conduit  system.  The  current  is  transformed  to  220  volts,  three 
phase  for  power  purposes,  and  to  220  volts — 110  volts  single 
phase  for  lighting  purposes.  Transformers  located  near  each 
tower  supply  current  for  the  towers,  and  also  for  the  nearby 
signal  bridges.  The  remaining  transformers  are  ?x>  located  as 
to  supply  two  or  more  outlying  signal  bridges.  The  lighting 
transformers  are  arranged  in  pairs,  with  secondaries  in  multiple 
so  that  there  are  two  sources  of  power  for  each  circuit,  either 
transformer  being  able  to  carry  the  total  load.  Induction-motor 


Fig.    2889.      Power    Room    for    Electric    Interlocking    Plant.      Federal    Signal   Company 


Figs.  2889-2893 


ACCESSORIES. 


generator  sets  are  provided  in  duplicate  for  each  battery  lo- 
cated in  the  towers.  The  generators  are  shunt  wound  with  wide 
variation  of  voltage.  A  motor  generator  is  running  continuously 
in  multiple  with  each  battery,  taking  most  of  the  load,  the 
battery  helping  out  on  the  peaks.  Automatic  underload  circuit 
breakers  are  provided  for  opening  the  generator  circuits  in  case 
of  failure  of  the  alternating  current  supply.  All  motor  genera- 
tors are  of  the  same  type,  the  voltage  range  being  from  four  to 
40.  The  generators  are  capable  of  charging  from  one  to  16 
cells  of  battery. 

Current  for  the  lever  locks  of  the  interlocking  machines  is 
supplied  from  a  220  to  55  volt  transformer  and  the  illuminated 
track  diagram  is  fed  from  a  220  to  14,  12,  and  10  volt  trans- 
former. If  the  alternating  current  fails  an  emergency  switch 
will  connect  up  the  locks,  and  the  plants  are  then  operated 
without  the  diagrams. 

At  one  plant  (Lake  street  plant)  power  is  received  from  three 
single-phase  transformers  delta  connected,  located  in  the  power 
house  and  furnishing  320  volts. 


Fig.   2889. 


Interlocking    Plant    Power    Room    Equipment. 

Southern  Pacific. 
POWER  SWITCHBOARDS 


Fig.    2891.     Interlocking    Plant    Power    Room    Equipment. 
Pennsylvania   Railroad. 


Fig.       2890.       Power      Switchboard 
Panel.     General  Railway  Sig- 
nal   Company. 


Fig.    2892.      Switchboard     for    Electric 

Interlocking  Plant.   New  York,  New 

Haven  &  Hartford.    The  Union 

Switch  &  Signal  Company. 


Fig.        2893.       Power 
Switchboard.        Ameri- 
can      Railway       Signal 
Company. 


4i8 


ACCESSORIES. 


Figs.  2894-2896 


Fig.  2894.     Arrangement  of  Switchboards  and  Generat- 
ing Apparatus.     S.  P.  &  S.  R.  R.     General  Rail- 
way   Signal    Company. 


Fig.  2895.     A.  C.  and  D.   C.   Switchboard   Installed  on 
the  New  York  Central.     General  Elec- 
tric  Company. 


Fig.  -2896.     Switchboard   for   Sub-Station  as   Furnished    for  the  Electric  Zone  of  the  New  York  Central  &  Hud- 
son River  by  the  General  Railway  Signal  Company. 


Figs.  2897-2898 


ACCESSORIES. 


419 


Fig.    2897.     Front    View    of    Power    Switchboard.     General   Railway  Signal  Company. 


Fig.   2898.     Rear   View    of    Power    Switchboard.      General    Railway   Signal   Company. 


420 


ACCESSORIES. 


Figs.  28gg-2g( 


AAMMMAA 

~HO  Volts+l  10  Volts  - 


-  22O  Volts 

wvwvww 


Fig.  2899.     Switchboard  for  Alternating  Current  Track  Circuit  _  Block     Signal     System. 

Transit    Company.      The    Union    Switch    &   Signal    Company. 

MERCURY  ARC  RECTIFIERS. 

GENERAL,      ELECTRIC      MERCURY      ARC      RECTIFIER. 

The  mercury  arc  rectifier  consists,  as  its  name  implies,  of  a 
mercury  vapor  arc.  This  arc  is  enclosed  in  an  exhausted  glass 
vessel  of  peculiar  construction,  which  can  be  seen  in  the  center 
of  the  switchboard,  Figs.  2903-2905,  and  in  Fig.  2909. 

Mercury  vapor  in  its  ordinary  or  molecular  condition  is  prac- 
tically a  non-conductor  of  electricity.  Such  vapor  might  be 
formed  by  applying  heat  to  a  mass  of  mercury  enclosed  in  a 
vacuous  chamber.  If  a  body  of  vapor  thus  formed  were  sub- 
jected to  the  action  of  an  electromotive  force,  either  continuous 
or  alternating,  its  resistance  would  be  found  to  be  very  great. 
If,  however,  the  mercury  vapor  is  ionized,  in  other  words,  if 
the  atoms  of  mercury  in  this  vapor  are  electrified,  the  electrical 
resistance  to  the  flow  of  current  in  one  direction  will  be  very 
small,  while  its  resistance  to  current  flowing  in  the  opposite 
direction  will  still  be  great.  To  use  a  very  crude  analogy,  its 
action  on  an  electric  current  is  similar  to  the  action  of  a 
check  valve  on  a  current  of  water  flowing  through  a  pipe. 

The  ionization  of  mercury  vapor  is  easily  accomplished.  If 
an  arc  is  formed  between  one  mercury  electrode  and  another 
electrode,  the  mercury  being  the  negative,  ionized  mercury  vapor 
will  result.  When  a  mercury  arc  is  formed,  as  in  the  mercury 
arc  lamp,  the  negative  electrode  being  mercury,  the  resistance 
of  this  arc  Is  small,  but  only  to  current  of  one  direction.  Hence 
it  Is  seen  that  the  current  in  a  mercury  arc  must  be  uni-direc- 
tional.  This  brings  us  to  an  understanding  of  the  action  of  the 
rectifier.  A  mercury  cathode  is  provided  and  two  anodes  of 
suitable  material  are  connected  across  the  terminals  of  an  alter- 
nating current  circuit,  thus  becoming  alternatively  positive  and 
negative.  The  arc  shifts  from  one  anode  to  the  other  with  each 
alteration,  always  passing  from  a  positive  anode  to  the  negative 
cathode.  The  current  in  the  wire  connected  to  the  cathode  is, 
therefore,  always  in  the  same  direction. 

The   direct  current  delivered  by  the   mercury  are  rectifier  is 
very   different   in   its   characteristics   from   that   delivered   by   a 


Interborough     Rapid 


Insulating  Transformer 
2  2O  l/o/ts 


Fig.  2900.     Control  and  Operating  Circuits  for  Mercurjr 
Arc  Rectifier. 


Figs.  2901-2905 


ACCESSORIES. 


421 


synchronously  driven  rectifier.  The  current  from  a  synchron- 
ously driven  machine  consists  of  a  series  of  pulsations,  each 
separated  from  the  others  by  a  certain  small  interval.  If  we 
were  able  to  operate  a  mercury  arc  rectifier,  in  accordance  with 
the  above  theoretical  considerations,  without  any  accessory  ap- 
paratus, this  rectified  current  would  be  composed  of  a  series 
of  pulsations,  but  would  lack  the  separating  gaps  mentioned,  the 
current  wave  being  similar  in  form  to  the  impressed  alternating 
current  wave,  with  the  exception  that  the  negative  half 
would  be  transposed,  so  as  to  become  positive  with  reference 
to  the  zero  line.  This,  however,  is  not  the  case. 

All  types  of  mercury  arc  rectifiers  have  three  essential  parts, 
the  rectifier  tube,  the  main  reactance  and  the  panel.  The  rec- 
tifier tube  is  an  exhausted  glass  vessel  in  which  are  two 
graphite  electrodes  (anodes  A-A'),  Fig.  2900,  and  one  mercury 
cathode  (B).  Each  anode  is  connected  to  a  separate  side  of  the 
alternating  current  supply,  and  also  through  one-half  of  the  main 
reactance  to  the  negative  side  of  the  load.  The  cathode  is 
connected  to  the  positive  side.  There  is  also  a  small  starting 
electrode  (C)  connected  to  one  side  of  the  alternating  current 
circuit  through  resistance,  and  used  for  starting  the  arc.  When 
the  rectifier  tube  is  rocked,  so  as  to  form  and  break  a  mercury 
bridge  between  the  cathode  (B)  and  the  starting  anode  (C),  a 
slight  arc  is  formed.  This  starts  what  is  known  as  the  "exci- 


tation" of  the  tube,  and  the  cathode  begins  supplying  ionized 
mercury  vapor.  This  condition  of  excitation  can  be  kept  up 
only  as  long  as  there  is  current  flowing  toward  the  cathode 


rr 


Fig.  2902.     Rear  View  of   Operating  Board,  Fig.  2901. 

fo/t/neter 

a 


stands 

LOGO' Resistance  — 
Circuit  Breaker 


\-/<fnmeter 
RectifierS/iater 
/J/xjde  Switch 
Starting  Smtch 
£ine  Switch 

fuse 


i-  -/feactance 


Fig.  2901.     Front  View  of   Mercury  Arc  Rectifier   Oper- 
ating  Board.     General  Electric  Company. 


Figs.  2903-2905.     Mercury  Arc  Rectifier  and  Operating 
Board.     General   Electric   Company. 


422 


ACCESSORIES. 


Figs.  2906-2909 


Figs.  2906-2907.    Standard  Battery  Charging  Rectifier  Set.    Gen- 
eral Electric  Company. 


Fig.      2908.        Single-Phase 
Mercury    Arc    Rectifier 
for  Use  with  Rail- 
way     Signal 
Batteries. 


B 


Fig.  2909.     Mercury  Arc  Rectifier  Tubes. 
Names  of  Parts  of  Mercury  Rectifier  Tubes;  Fig.  2909. 
A    Anods.  C    Starting  Anode. 


B     Cathode. 


D     Mercury  Vapor  Tube. 


Figs.  2910-2914 


ACCESSORIES. 


423 


If  the  direction  of  supply  voltage  is  reversed,  so  that  the 
formerly  negative  electrode,  or  cathode,  becomes  positive  with 
the  reversal  of  the  alternating  current  circuit,  the  current 
ceases  to  flow  ;  since,  in  order  to  flow  in  the  opposite  direction, 
it  would  require  the  formation  of  a  new  cathode,  which  can 
be  accomplished  only  by  special  means.  Therefore,  in  the  rec- 
tifier tube,  the  current  must  always  flow  toward  the  cathode 
which  is  kept  in  a  state  of  excitation  by  the  current  itself. 

Such  a  tube  would  cease  to  operate  on  alternating  current 
voltage  after  one-half  the  cycle,  if  some  means  were  not  pro- 
vided to  maintain  the  flow  of  current  continuously  toward  the 
cathode. 

The  maintenance  of  the  current  flow  is  accomplished  by 
the  main  reactance.  As  the  current  alternates,  first  one  anode 
and  then  the  other  becomes  positive,  the  current  flowing  from 
the  positive  anode  through  the  mercury  vapor,  toward  the 
cathode,  thence  through  the  battery,  or  other  load,  and  back 
through  one  half  of  the  main  reactance  to  the  opposite  side 
of  the  alternating  current  supply  circuit.  As  the  current  flows 
through  the  main  reactance,  it  charges  it,  and  while  the  value 
of  the  alternating  wave  is  decreasing,  reversing  and  increas- 
ing the  reactance  discharges,  thus  maintaining  the  arc  until  the 
voltage  reaches  the  value  required,  to  maintain  the  current 
against  the  counter  e.  m.  f.  of  the  load,  and  reducing  the  fluc- 
tuations ia  the  direct  current.  In  this  way,  a  true  continuous 
current  is  produced  with  very  little  loss  in  transformation. 

That  there  may  be  no  misapprehension,  it  should  be  particu- 
larly noted  that  the  rectifier  is  so  designed  that  the  entire  alter- 
nating current  wave  is  used.  This,  of  course,  means  that  the 


then  positive,  and  the  arc  is  free  to  flow  between  "A"  and  "B." 
Following  the  direction  of  the  arrow  still  further,  the  current 
passes  through  the  battery  "J,"  through  one-half  of  he  main 


2910.      Mercury   Arc    Rectifier    Mounted    on 
Front    of    Operating    Board.      General 
Electric  Company. 

rectifier  has  approximately  twice  the  efficiency  that  would  be 
obtained  if  only  one-half  or  the  alternating  current  wave  were 
used. 

To  get  an  idea  of  the  operation  of  the  mercury  arc  rectifier, 
assume  that  the  instant  the  terminal  "H"  of  the  supply 
(or  insulating)  transformer  is  positive,  the  anode  "A"  is 


Figs.   2911-2913.     Control   Apparatus   for   Mercury   Arc 
Rectifier.     General   Electric   Company. 


Fig.  2914.    Rectifier  Outfit  at  Communipaw,  N.  J.,  Elec- 
tro-Pneumatic Interlocking  Plant.     Central 
R.    R.   of   New  Jersey. 

reactance  coil  "E/'  and  back  to  the  negative  terminal  "G"'  of 
the  transformer.  When  the  impressed  e.  m.  f.  falls  below  a 
value  sufficient  to  maintain  the  arc  against  the  counter  e.  m.  f. 
of  the  arc  and  load,  the  reactance  "E,"  which  hereto  has  been 
charging,  now  discharges,  the  discharge  current  being  In  the 
same  direction  as  formerly.  This  serves  to  maintain  the  arc 


424 


ACCESSORIES. 


Figs.  2915-2920 


In  the  rectifier  tube  until  the  e.  m.  f.  of  the  supply  has  passed 
through  zero,  reversed,  and  built  up  to  such  a  value  as  to 
cause  the  anode  "A"  to  have  sufficient  positive  value  to  start 


.  30  .  45     ..      .  .          .        se  -6,/7  */Z, 


Fig.   2915.     Control  and   Operating   Circuits    for   Mercury 
Arc  Rectifier.     General  Electric  Company. 


the  arc  between  it  and  the  cathode  "B."  The  discharge  circuit 
of  the  reactance  coil  "E"  is  now  through  the  arc  "B"  instead 
of  through  its  former  circuit.  Consequently  the  arc  A'B  is 
now  supplied  with  current,  partly  from  the  transformer,  and 
partly  from  the  reactance  coil  "E."  The  new  circuit  of  the 
transformer  is  indicated  by  the  arrows  enclosed  in  circles. 

The  rectifier  set  shown  in  Fig.  2906  requires  a  floor  space  of 
approximately  16  in.  x  18  in.  and  has  a  height  of  64  in.  On 
the  panel  are  mounted  a  direct  current  voltmeter  and  ammeter, 
a  double  pole  switch  for  connecting  the  supply  circuit,  a  direct 
current  overload  circuit  breaker  for  the  load,  and  the  necessary 
switches  for  starting  the  rectifier  and  regulating  the  charg- 
ing current.  A  starting  resistance  on  which  the  rectifier  starts 
before  connection  to  the  battery,  is  mounted  on  the  back  of 
the  panel  and  is  operated  by  a  single  pole,  double-throw  spring 
switch  on  the  front. 

Accurate  voltage  control  is  obtained  by  means  of  a  double 
regulating  switch  on  the  front  of  the  panel.  This  switch  has 
two  sets  of  contact  buttons — six  in  one  set  for  rough  regula- 
tion and  eleven  in  the  fine  regulation  set.  It  is  possible  to 
obtain  a  very  wide  regulation,  practically  independent  of  the 
current  flowing.  The  contact  buttons  are  connected  to  rough 
and  fine  regulation  taps  brought  out  from  the  regulating  com- 
pensator mounted  on  the  back  of  the  panel. 

The  'rectifier  tube  differs  in  size  according  to  the  ampere 
capacity,  and  in  shape  according  to  the  direct  current  voltage 
at  which  it  is  to  be  used. 

The  terminals  of  the  rectifier  tubes  are  provided  with  metal 
caps  for  the  protection  of  the  electrodes  from  mechanical  injury 
and  for  convenience  in  making  connections.  The  rectifier  tube 
is  supported  at  the  back  of  the  tube  by  a  metal  holder,  so 
pivoted  and  connected  that  it  can  be  rocked  back  and  forth 
by  the  small  hand-wheel  on  the  front  of  the  board. 

The  reactance  which  maintains  the  arc  at  each  reversal  of 
the  alternating  current  is  connected  directly  across  the  sec- 
ondary of  the  regulating  compensator.  It  is  mounted  in  a  cast 
iron  case  and  stands  on  the  floor  beneath  the  panel. 


AIR^COMPRESSORS 


GENERAL,    ELECTRIC    AIR    COMPRESSORS. 


The  General  Electric  Co.'s  air  compressors  are  single  acting, 
single  stage,  with  horizontal  cylinders.  Connection  to  the 
motor  is  made  through  a  gear  and  pinion  having  accurately 
cut  herringbone  teeth.  The  frame  casting  completely  encloses 
all  working  parts  of  the  compressor  and  contains  both  the 
motor  and  crank-shaft  bearings.  Securely  bolted  to  this  frame 
is  the  motor  frame.  The  gear  is  located  in  the  middle  of  the 
crank  shaft  and  the  gearing  is  entirely  enclosed  in  the  crank 
case,  this  feature  eliminating  the  necessity  of  a  separate  gear 
case. 

All  bearings  and  working  parts  are  automatically  lubricated 
from  a  well  formed  in  the  compressor  frame,  immediately 
below  the  gear. 


Fig.  2916.     Motor  Driven  Air 
Compressor   with    Motor 
and    Compressor    Cov- 
ers   Removed.      Gen- 
eral Electric  Corn- 


Figs.      2918-2919.       Expansion 

Joint       for       Condenser. 

The  Union  Switch  & 

Siffnal  Company. 


Fig.  2917.     Ingersoll-Sergeant  Air  Compressor.     Terminal  Railway  Associa- 
tion of  St.  Louis. 


Fig. '      2920.        Ingersoll  -  Ser- 
geant "Class  "A-i"   Air 
Compressor. 


FigS.   2Q2I-2Q28 


ACCESSORIES. 


425 


2921.        Auxiliary 
Reservoir  and  Dwarf 
Signal  Foundation 
Combined. 


Fig.     2924.       Motor-Driven     Air     Compressors     for     Electro-Pneumatic 
Interlocking  Plant  at  East  New  York.    Brooklyn  Rapid  Tran- 
sit Company.     The  Union  Switch  &  Signal  Company. 


Fig.  2922.  Elevated 
Railroad  Type  of  Aux- 
iliary Reservoir.  The 
Union  Switch  &  Signal 
Company. 


Fig.  2925.     Hose  Connection  with  Union. 
Switch  &  Signal   Company. 


The  Union 


Fig.    2923.     Motor-Driven     Ingersoll-Rand     Air     Compressor     for     Elec- 
tro-Pneumatic  Interlocking   Plant  at  St.   George.     Baltimore 
&  Ohio.     The  Union  Switch  &  Signal  Company. 


Figs.  2926- 
2927.  Expan- 
sion Joint  for 
Air  Pipe.  The 
Union  Switch 
&  Signal  Com- 
pany. 


Fig.  2928. 
Auxiliary  Res- 
e  r  v  o  i  r.  The 
Union  Switch 
&  Signal  Com- 
pany. 


426 


ACCESSORIES. 


Figs.  2929-2934 


„«*•"* 

<VJ 

Figs.    2929-2930.     Method    of    Sup- 
plying    Air     to      Electro-Pneu- 
matic Signals    on    Bracket 
Post.     Pennsylvania 
Railroad. 


Fig.    2931.      Air    Compressor 
Governor.    General  Elec- 
tric   Company 


Fig.  2932.     Pipe  Insulation.     H.  W. 
Johns-Manville    Company. 


J248 


Fig.  2933.     Ingersoll-Sergeant  Motor-Driven  Air  Compressor.     Inter- 
borough   Rapid   Transit   Company. 


Fig.  2934.     Motor-Driven  Air  Compressors  and   Control  Switchboards  for  Electro-Pneumatic  Interlocking  Plant. 

Baltimore  &  Ohio.     The  Union  Switch  &  Signal  Company. 


Figs.  2935-2936 


ACCESSORIES. 


427 


Fig.   2935.     Three-Pressure   By-Pass   System  for   Electro- 

Pneumatic  Interlocking  Plants.     New  York  Cen- 

tral &  Hudson  River. 


Oir  Compressor 


•\g.  2936.     Standard   Connections  to  Air   Compressors,  Water   Cooler,   Air    Reservoir,    Cooling   Coils   and   Aux- 
iliary   Reservoir    for    Electro-Pneumatic    Interlocking    Plant.      New    York   Central    &    Hudson    River. 


Names   of  Parts  for  Three-Pressure  By-Path   System;  Fig.   2935. 


A    High  Pressure  Line 

B    Intermediate  Pressure 

C  High  Pressure  Foster  Reducing 
Valve 

D  Low  Pressure  Foster  Reducing 
Valve 

E    H.  P.  By-Path 

F    L.  P.  By -Path 

G    2"  Globe    Valves 

H     2"  Flange   Unions 

I      2"  Ts 

J      2"  Us 

K  2"  x  2"  x  24"  7"-y  /cr  Hose  Con- 
nections 


L  1 1'  Globe  Valve 

M  i"  Union 

N  Pn'/»  Tfl»A'  or  Reservoir 

O  Intermediate     Pressure     Storage 

Tank 

P  7.  P.  Gong* 

Q  L.  P.  Gauge 

R  //.  P.  Gauge 

S  5//>/t0M  Pi/)* 

T  2"  x  i"  x  2"  T 

U  Floor  Line 

V  2"  x  6"  Nipples 

W  2"  x  7r/^"  Nipples 

X  L.  P.  .SVorfl?*'  To;;/,- 


428 


ACCESSORIES. 


Figs.  2937-2942 


Fig.  2937.     Air   Compressor   Plant  Using  Air  Brake    Apparatus.      New   York,    Ontario    &  Western. 


Fig.   2939.     "Kewanee"     Brass 
and  Malleable  Iron  Self-Seat- 
ing Ball  Joint  Flange  Un- 
ion.    National  Tube 
Company. 


Fig.  2940. 


Fig.  2938.     Cooling    Coils     and     Drip 
Tanks  for  Electro-Pneumatic  In- 
terlocking Plant.     New  York, 
Ontario    &   Western. 


Fig.  2941.  Fig.    2942. 

Figs.  2940-2942.     Pipe  Unions  with  Ground   Brass   Seats. 
National  Tube   Company. 


POWER  SUPPLY  CIRCUITS 


NEW  YORK,    ONTARIO   &    WESTERN". 

Fig.  2943  is  a  diagram  of  circuits  and  apparatus  for  supply- 
ing electric  power  to  the  electro-pneumatic  interlocking  plant 
at  Fallsburgh  Tunnel,  on  the  New  York,  Ontario  &  Western, 
where  double  track  converges  into  single  track  through  the 
tunnel  and  one  plant  controls  the  switches  and  signals  at  both 
ends.  Current  is  normally  furnished  by  one  of  the  air-driven 
generators,  supplied  with  air  from  the  switch  and  signal  mains. 
One  generator  is  held  in  reserve  and  a  primary  battery  is  also 


installed  of  sufficient  capacity  to  operate  the  plant  should 
both  generators  break  down  at  the  same  time.  Indicator  A  is 
controlled  by  a  track  circuit  through  the  tunnel.  It  has  a  stick 
wiring  (not  shown)  so  arranged  that  after  the  train  enters  the 
section  with  a  clear  signal,  the  indicator  cannot  pick  up  until 
the  train  has  left  the  section  and  the  signal  has  been  restored 
to  the  normal  position.  As  shown  the  indicator  breaks  all 
signal  control  circuits.  The  relay  B  is  also  controlled  by  the 
indicator,  and  in  turn  controls  lock  circuits  for  the  units. 


Figs.  2943-2949 


ACCESSORIES. 


429 


Figs.  2944-2945.  Flange 
Union. 


Figs.   2946-2947.  ^Insu 
lated  Flange  Union. 


Fig.  2943.     Circuits  for  Power  Supply,  Electro-Pneumatic  Interlock- 
ing Plant.     New  York,  Ontario  &  Western. 


3  5 fop  Cock 


Fig.  2948.     Standard   Piping  and  Water  Cooling  Con-      Fig.   2949.     Alcohol   Inlet   Valve   for   Air   Pipe.     New 
nections    for   Air    Compressor    Plants.  York  Central  &  Hudson  River. 


430 


ACCESSORIES. 


Figs.  2950-2962 


BATTERY  CHARGING  SWITCHES 


GENERAL    ELECTRIC    BATTERY    CHARGING    SWITCH. 

In  the  battery  charging  switch  manufactured  by  the  General 
Electric  Co.  the  charging  line  is  connected  to  each  side  of  the 
two-pole  switch,  and  the  duplicate  sets  of  batteries,  which 
are  charged  alternately,  and  the  signals  or  other  apparatus 
to  be  operated  are  connected  to  the  four-pole  switch.  By  the 
interlocking  device  contained  in  the  handle  it  is  impossible  to 
reverse  the  four-pole  switch  without  throwing  in  a  resistance 
in  the  line  with  the  two-pole  switch.  This  resistance  is 
mounted  in  fuse  clips  and  can  be  easily  removed. 


Fig.   2950.     Battery  Charging  Circuit.     New  York, 
Ontario    &    Western. 


HAI.L   BATTERY    CHARGING   SWITCH. 

The  charging  switch  shown  in  Fig.  2963  consists  of  a  base 
of  asbestos  wood,  upon  which  is  mounted  a  central  shaft  pro- 
vided with  a  suitable  hand  crank.  Rigidly  fastened  to  the  shaft 
are  a  number  of  contact  segments.  These  segments  are  insu- 
lated from  the  shaft,  and  from  each  other.  When  the  shaft  is 
partially  revolved  the  segments  engage  with  or  are  withdrawn 
from  certain  of  the  contact  jaws,  thus  opening  or  closing  the 


Figs.  2952-2955.     Four-Pole   Double  Throw  Knife  Cir- 
Fig.  2951.     Interlocking  Type  Battery  Charging  Switch          cuit    Controller    (Battery   Charging    Switch).      The 
for  Railway  Signals.     General  Electric  Company.  Union  Switch   &  Signal  Company. 


•*-  CH0KIH6  LINE  — 


-—  CHARGING  LIN£ 


HttHPLf  IN  FVSir/ON  ' 


Figs.    2956-2962.     Battery    Charging    Switch    and    Operating    Circuits.      Federal 

Signal  Company. 


Figs.  2963-2969 


ACCESSORIES. 


desired  circuits.  The  hand  crank  of  this  switch  is  provided  mediate  positions.  Fig.  2964  shows  a  number  of  the  Hall  Signal 
with  a  latch  having  a  spring  plunger,  which  automatically  Company's  battery  charging  switches  as  installed  on  the  New 
locks  the  switch  in  cither  extreme  position  or  one  of  two  inter-  York  Central. 


•Tf  f 

M-i  •: 

4    \       !       J  * 


Fig.    2963.     Battery    Charging    Switch. 
Company. 


Hall    Signal 


G.    R.    S.    BATTERY    CHARGING    SWITCH. 

Fig.  2965  illustrates  the  General  Railway  Signal  Company's 
battery  charging  switch  for  connecting  storage  batteries  in 
series  with  charging  and  discharging  lines. 

During  the  manipulation  of  the  switch  the  battery  is  not 
short-circuited  while  being  connected  to  the  line,  nor  is  the 
series  line  interrupted.  The  design  is  such  that  a  resistance 
is  automatically  inserted  during  the  interval  that  the  battery 
would  otherwise  be  on  short  circuit,  which  resistance  is  again 
cut  out  as  soon  'as  the  short-circuiting  point  is  passed  by  the 
contact. 

Manipulation  of  the  switch  is  simple,  the  four  different  posi- 
tions of  the  switch  controlling  the  batteries  being  as  shown  in 
the  following  table  : 

1 — Battery  A  discharging ;   battery  B   charging. 

2 — Battery  A  discharging ;  battery  B  open. 

3 — Battery  B  discharging  ;  battery  A  open. 

4 — Battery  B  discharging ;   battery  A  charging. 

The  contact  plates  and  fingers  are  large  and  designed  to  take 
can-  of  the  heavy  currents  necessary  in  this  kind  of  service 
without  heating. 

Figs.  2966-2969  show  the  circuits  for  the  battery  charging 
switch,  Fig.  2965.  Fig.  2966  shows  the  connections  while  bat- 
tery A  is  discharging  and  battery  B  is  charging;  Fig.  2967 
shows  the  connections  while  battery  A  is  discharging  and 
battery  B  is  open;  Fig.  2968  shows  the  connections  while  bat- 
tery B  is  discharging  and  battery  A  is  open ;  and  Fig.  2969 
shows  the  connections  with  battery  B  discharging  and  battery 
A  charging. 


Fig.    2964.     Charging    Switches    in    Box.      Hall    Signal      Fig.    2965.     Battery    Charging    Switch.      General    Rail- 
Company,  way    Signal    Company. 


-s^       ' 

r  \  / 


Bat    A     Discharging 
Rat     B      Charging 


Bat    A     Discharging 
Beat.    B    Open 


I <&/  _-   4 


Sat     B     Discharging 
Bat  Pt   Open 


Bat.    B     Discharging 
Bat.   F\  Charcjinci 


Figs.    2966-2969.     Circuits    for    General    Railway    Signal  Company's    Battery    Charging   Switch. 


432 


ACCESSORIES. 


Figs.  2970- 


TRANSFORMERS 


Fig.  2970.     Core  and  Coils  of  Type 
"H"   Line   Transformer  Oil- 
Cooled.      General    Elec- 
tric  Company. 


Fig.    2971.     Secondary    Side    Type 
"H"    Line    Transformer.      Gen- 
eral   Electric    Company. 


Fig.  2972.     Type  ~'H"  Form  K  Line 
Transformer.       General     Elec- 
tric   Company. 


Fig.   2974.     Type   "N.    D."    Lighting 
Transformer  110/10  Volts.    Gen- 
eral   Electric    Company. 


Fig.    2975.     Type    "Y"    Form    "B" 

Lighting    Transformer     110/10 

Volts.     General   Electric 

Company. 


Fig.    2973.     Type    "N.     D."    Form 

3  Lighting  Transformer  no/8-io 

Volts.    Air  Cooled.    General 

Electric   Company. 


Figs.  2976-2977.     Relay  Transformer.     General  Railway  Signal  Company. 


G.    R.    S.    SIGNAL   TRANSFORMERS. 

The  G.  R.  S.  Co.'s  Type  II.  transformer,  Figs.  2970-2972, 
Is  for  use  at  signal  and  track  feed  locations.  It  is  designed 
to  step  down  directly  from  the  transmission  line  voltages  to 
those  required  for  the  operation  of  the  signal  system.  These 


transformers  are  made   in  various   sizes,  as  required,  and  maj 
be    provided   with   any   reasonable    number   of   independent    sec 
ondary  coils,  each  terminating  in  binding  posts  located   withl 
the  transformer,  thus  doing  away  with  a   number  of   externs 
leads   which    may    or    may    not   be    required. 


REACTANCES  AND  RESISTANCE  UNITS 


UNION  REACTANCE  COIL  FOR  ELECTRIC  ROAD  TRACK  CIRCUITS. 

This  coll  is  designed  for  connection  between  the  transformer 
and  track  in  electric  road  track  circuits  of  the  double  rail 
system  with  impedance  bonds.  On  account  of  the  larger  cur- 
rent values  encountered  in  this  system,  much  heavier  copper 
and  fewer  turns  are  required. 

Suitable  terminals  are  provided  for  connecting  directly  to  the 
coil  winding,  and  no  taps  provided.  Adjustment  of  the  impe- 
dance of  the  coil  is  secured  by  varying  the  air  gap  in  the  mag- 


netic circuit,  which  is  accomplished  by  loosening  the  suppor 
ing  clamps  and  raising  or  lowering  the  upper  half  of  the  cor 
Fibre  spacers  of  the  proper  thickness  determine  the  air  gaj 
By  this  means  the  impedance  may  be  varied  from  0.1  to  l.J 
ohms,  25  cycles. 

The  coil  is  impregnated  by  the  vacuum  process  and  thoroughlj 
weather-proof.  The  capacity  of  this  type  of  reactance  coil  Is 
10  volts,  60  amperes,  25  cycles,  and  the  power  factor  about 
10  per  cent. 


Figs.  2978-2982 


ACCESSORIES. 


433 


UNION   REACTANCE   COIL  FOR   STEAM   ROAD  TRACK    CIRCUITS. 

The  coll  shown  in  Figs.  2979-2980  is  designed  for  connection 
between  the  transformer  and  track  in  steam  road  alternating  cur- 
rent track  circuits,  and  limits  the  flow  of  current  from  the 
transformer  when  the  track  circuit  Is  shunted  by  a  train.  It 
consists  of  a  single  coll  with  uniformly  graded  taps  brought  out 
to  terminal  posts,  the  coil  being  enclosed  in  a  laminated  mag- 
netic circuit  containing  an  adjustable  air  gap.  A  suitable 
wooden  base  provides  a  convenient  means  for  mounting  in  the 
back  of  the  relay  compartment.  The  number  of  taps  provide 


any  time  should  special  track  conditions  demand  it.  In  order 
to  secure  a  maximum  degree  of  flexibility  the  terminals  are 
made  of  four  350,000  c.  m.  standard  cables. 

The  bond  may  be  filled  with  either  transformer  oil  or  petro- 
latum. When  the  latter  is  used,  the  bonds  are  filled  and  sealed 
ready  for  Installation  before  they  leave  the  factory.  This  con- 
siderably decreases  the  labor  of  Installation  and  minimizes  the 
possibility  of  defective  sealing  and  the  consequent  admission  of 
water. 

This  bond  is  rated  at  1,500  amperes  per  rail  continuous 
capacity,  or  2,000  amperes  per  rail  for  one  hour,  and  may  b« 
adjusted  to  have  a  variation  of  less  than  10  per  cent  In  impe- 
dance with  an  unbalancing  of  800  amperes. 


Fig.    2978.     Single    Winding   Reactance    Coil. 
Union  Switch  &  Signal  Company. 


The 


sufficient  variation  in  impedance  to  take  care  of  ordinary  adjust- 
ments, and  a  greater  range  may  be  obtained  by  varying  the  air 
gap  in  the  magnetic  circuit. 

As  the  coil  has  an  extremely  low  power  factor,  the  watt 
energy  consumed  is  extremely  small,  resulting  in  a  considerable 
saving  in  power,  the  saving  over  that  required  were  a  resistance 
used  for  the  same  purpose  usually  being  from  30  per  cent  to  50 
per  cent  of  the  total  power  supplied  to  the  track  circuit,  an 
amount  sufficient  at  the  usual  costs  for  power  to  pay  in  a 
short  time  for  the  difference  in  cost  between  the  reactance  coil 
and  a  resistance  tube. 

The  coil  is  designed  for  operation  on  either  25  or  60  cycles. 
;ind  has  a  maximum  capacity  of  30  volts,  15  amperes. 


UNION    IMPEDANCE  BOND. 

The  type  of  impedance  bond  shown  in  Figs.  2981-2982  repre- 
sents a  considerable  advance  in  construction  over  types  previously 
la  use.  The  winding  consists  of  a  nine-turn  coil  of  copper  strap 
In  two  sections  of  four  and  one-half  turns  each,  wound  in  a 
spiral  with  edges  vertical.  Ducts  are  provided  between  the 
successive  turns  to  secure  ample  oil  circulation.  Means  are  pro- 
vided for  readily  varying  the  air  gap  in  the  magnetic  circuit  at 


Figs.     2979-2980.      Reactance     Coil     for    Steam     Road 

Track  Circuits.     The  Union  Switch  &  Signal 

Company. 


SECTIONAL  SIDE  VIEW. 

Figs.   2981-2982.     Impedance   Bond   with    Spiral  Wound   Coil.     The  Union    Switch  &  Signal  Company. 


ACCESSORIES. 


Figs.  2983-2993 


Figs.   2983-2984.     Sectionalizing   Panel   With  Trans- 
former   Housing.     General  Electric  Company. 


Fig.  2985.     Type  "NS"   Form  "D" 

Reactance.       General     Electric 

Company. 


G.    R.     S.     AUTOMATIC    REACTANCE. 

Fig.  2989  illustrates  the  automatic  reactance  manufactured 
by  the  General  Railway  Signal  Company.  The  device,  which  is 
used  in  A.  C.  signaling,  is  inserted  in  one  of  the  track  trans- 
former leads  to  the  rail,  to  limit  the  current  fed  to  the  track 
circuit  when  a  train  Is  present.  Its  use  is  of  particular  advan- 
tage where  the  energy  taken  by  the  track  circuit  is  large.  The 
automatic  reactance,  thus  installed,  takes  the  place  of  the  ordin- 
ary resistance  or  fixed  reactance  employed  for  that  purpose. 
When  the  track  circuit  is  unoccupied,  the  automatic  reactance 
presents  practically  no  resistance  to  the  passage  of  the  cur- 
rent to  the  rails,  but  with  the  train  present,  limits  the  current 
to  a  predetermined  amount  much  less  than  is  the  case  with  the 
ordinary  resistance  or  reactance.  Furthermore,  it  affords  broken 
down  joint  protection,  the  design  being  such  that  should  the 
track  insulation  break  down,  the  current  which  would  thereby 
be  fed  to  the  relay  of  the  adjacent  section,  will  have  practically 
the  same  phase  displacement  as  the  current  flowing  in  the  local 
of  that  relay  and  thus  will  not  cause  its  false  operation.  The 
automatic  reactance  has  no  moving  wires  or  contacts.  Its  size 
and  the  fact  that  it  does  not  become  heated,  permit  it  to  be 
installed  in  ordinary  relay  boxes. 


Fig.    2987.      Mounted    Resistance    Units    for    Railway 
Signals.      General    Electric    Company. 


Fig.   2988.     Type   "SU"    Resistance   Units. 
Electric   Company. 


General 


OENKUAI.    ELECTRIC    RESISTANCE    UNITS. 

The  General  Electric  Company's  type  SU 
resistance  units  aBe  used  principally  for 
track  circuit  work,  to  prevent  short  circuit 
when  the  track  is  occupied,  and  to  afford  a 
suitable  means  for  voltage  regulation.  The 
frame  consists  of  cast  iron  supports  with  a 
sheet  iron  connection  on  the  bottom  and  a 
wooden  top  plate  which  contains  the  termi- 
nals. 


Fig.   2989.     Automatic   React- 
ance.    General  Railway  Sig- 


nal Company. 


Fig.   2986.     Type  "R.   S."   Form   I 

Reactance.      General    Electric 

Company. 


i  era 


Figs.    2990-2993.     Miscellaneous    Group    of    Resistance   Units. 
General    Electric    Company. 


Figs.  2994-2998 


ACCESSORIES. 


435 


SWITCHES  AND  CIRCUIT  BREAKERS 


GENERAL     ELECTRIC     OIL     BREAK     SWITCH. 

The  oil  break  switch  Is  adapted  particularly  for  use  on  alter- 
nating current.  It  can  be  used  simply  as  a  switch  to  open 
or  close  the  circuit  by  hand  or  when  equipped  with  automatic 
features  will  give  automatic  protection  against  the  effects  of 
predetermined  abnormal  conditions.  The  switch  Interrupts  an 
electrical  circuit  in  oil  without  producing  abnormal  disturb- 
ances in  that  circuit.  It  confines  the  destructive  arc  to  a 


current  passes  through  zero  (at  which  point  the  electro-mag- 
netic energy  is  a  minimum),  which  enables  the  oil  break  switch 
to  interrupt  the  circuit  with  very  little  disturbance  and  with 
no  appreciable  surge  on  the  line. 


GENERAL  ELECTRIC   CIRCUIT   BREAKER. 

The  function    of   a   circuit   breaker    is   automatically   to   pro- 
tect electrical  apparatus  from   undesirable  effects   arising  from 


Fig.     2995.      Type     "C"     Form     "G' 

Circuit     Breaker     With     One 

Overload    and     One    Low 

Voltage   Coil. 


Fig.      2996.     Type     "C"     Form    "G" 

Circuit      Breaker,      Front 

Connected. 


Fig.     2994.     Type     "C"     Form     "P" 

Double  Pole  Circuit  Breaker, 

General  Electric  Company. 


Fig.    2997.     Type    "K-I2"    Oil    'Switch,     Solenoid    Oper- 
ated, on  Pipe  Framework. 

small  volume,  thereby  preventing  Its  spread  to  adjacent  appa- 
ratus and  can  therefore  be  safely  placed  In  any  convenient 
location  on  the  switchboard  or  in  the  power  station. 

When    the    switch    Is    opened   the    alternating  current,    which 
tends   to  maintain   an  arc  in   the  oil,  Is  Interrupted  when  the 


Fig.  2998.     "K-I2"     Oil     Switch     With     Oil     Vessel 
Lowered,  Showing  Contacts. 

abnormal  conditions,  such  as  overload  or  short  circuit,  under- 
load, low  voltage,  over  voltage,  reverse  current,  reverse  phase 
or  combinations  of  these  conditions.  It  Is  a  very  flexible  piece 
of  apparatus  and  can  be  used  to  act  instantaneously,  after  a 
predetermined  time  limit,  or  in  a  certain  sequence. 


436 


ACCESSORIES. 


Figs.  2999-3012 


The  automatic  operation  of  a  circuit  breaker  is  usually  ac- 
complished by  an  electro-magnet,  the  current  coil  of  which  is 
connected  in  series  with  the  circuit  and  carries  all  the  current 
flowing  through  that  circuit.  The  power  of  the  electro-magnet 
depends  on  the  amount  of  this  current  and  not  on  the  voltage. 

A  potential  coil  is  connected  across  the  line  and  carries 
only  that  fraction  of  the  total  current  that  the  voltage  of  the 


system  can  force  through  its  high  resistance  winding  and 
series  resistance.  The  power  of  this  electro-magnet  depends 
upon  the  potential  of  the  system,  and  not  in  any  way  upon 
the  amount  of  current  flowing  in  that  system. 

Overload  and  underload  protection  is  secured  by  the  use  of 
current  coils.  Low  voltage  and  shunt  trip  attachments  are 
actuated  by  potential  coils. 


WIRING  AND  DETAILS. 


Figs.  2999-3001.     Primary  Cut  Outs.     General  Electric 
Company. 


ing  Wf 


"C 


4 

j 

* 

_3L 


•i. 

g      J 
1      I 

?      $ 

ll 


O-C 


yVo.g  Signal 


ndica 


Indicator 


1 


tf-Home 


i 


t 

IS 


I 

3 


ing  W 


—  C 


fio.l  Signal 


cator 


6 
°\ 


'nc/icafor 


No.  4  Signal 


flo.3  Signal 


Figs.  3003-3004. 
Line  Wire  Dead 
End.  Chicago  & 
North- Western. 


Positive.  Charging  Wir*  on  Track  Side. 

Fig.  3002.      Standard  Arrangement  of  Line  Wires   for 

Automatic    Block    Signals.      Lake    Shore    & 

Michigan  Southern. 


Figs.  3005-3006. 
Method  of  Tying 
Iron  Line  Wire 
to  Insulator.  Chi- 
cago &  North- 
Western. 


Fig.     3007.       High     Tension     Pol< 

and  Line.     New  York  Central 

&   Hudson  River. 


\ 

n  i'"v* 

t* 

r 

k-C<>rr/T7O/7  to/  re 

A. 

I 

d 

®  : 

:f 
L 

hii 

b 

Trcrch  sic/e. 

f~%  -P/airry/a^s 
Sr   /nsu/afo/- 


te± 


**/Sfe<*/  P/ttr—  -"| 


g  x3g  /  a^/Scre  uj~  ^  _  ^- 
I'*?, 

-JOJ 


Oak  bracket. 


\ 


^^ 


y^  ^ 

^x/^Ga/v'c/  Iron 
~<3Od  tjo/re  nail. 
-30d  w/re  naif. 

7~<s/es  /o  be 


3&frar-rc/  mcrrf/rre 
every  S4in 


Figs.   3008-3012.     Details   of   Pole   Construction   and   Wiring.      Southern  Pacific-Union  Pacific. 


Figs.  3013-3034 


ACCESSORIES. 


437 


- -  \--3^ 

k- si'- >k 2/-  — >k 2/- 4^K- L 


Figs.  3013-3014.     Standard     Four-Pin     Cross     Arm, 
Southern  Pacific-Union  Pacific. 


r*i 


Fig.  3015.     Method  of  Bringing  Cable  into  Mechanism 
Case.     Union    Pacific. 


Figs.    3016-3018.      Iron    Pole    Pin    and    Wooden 
Bracket.      Southern    Pacific. 

On  Straight  Track 


Figs.  3019-3020.     Standard  Glass  Insulators.     Southern 
Pacific-Union    Pacific. 


=N 


oN-'S        $> 


I       I       I         I 

|     *     *      <3 

On  Curve 
\        \       \  \ 


1       -6    Track 


<5i    Side 


\ \ 


Position  of  Wires 

Figs.  3021-3022.     Location   of   Sig- 
nal Wires  on  Poles.     Chicago 
&    North-Western. 


/8- Copper  77e  Wire 


\  Clearance 

«''  ES 

18'b'far.  Highway_ 
~ H 


Fig.  3025.     Standard  Clearance  for 
Line  Wire.     Chicago  &  North- 
Western. 


a.s.a.  /O7O 


Figs.  3023-3024.     Method  of  Tyin: 
Copper   Line   Wire    to   Insula- 
tor.      Chicago     &     North- 
Western. 


i     g     i  4 

Fig.  3026.     R.   S.  A.   Standard  Terminal  Block. 


Fig.  3027.     Copper  Terminal   Fuse. 


Figs.    3028-3030.      Premier    Seamless    Sleeve.      Bryant 
Zinc  Company. 


Figs.    3031-3034.    Wire    Terminals. 
Bryant  Zinc  Company. 


438 


ACCESSORIES. 


Figs.  3035-3043 


3jT-          -    ^-_pEqp- 


n 


^k 


f-r 


k--^->) 


OM^- 

?- 


^ 

£ecr&e&/. 


±^^^ 


Figs.  3037-3038-   Junction  Box  on  Iron  Cable  Post,  with 

Cross  Arm.     Lake  Shore  &  Michigan  Southern. 

The  Union  Switch  &  Signal  Company. 


5/8" Nook  Bo/t 


Figs.    3035-3036.      Junction    Box    Attached    to    Pillar. 

Interborough  Rapid  Transit  Company.     The  Union 

Switch  &  Signal  Company. 


K- /p£- -H 

— - --^--    ~*— 


.± 


Figs.   3039-3040.      Iron   Junction    Box. 
Michigan  Central. 


Fig.  3041.    Fuse  and  Junction  Box.     Railroad  Supply 
Company. 


Figs.  3042-3043.     Junction   Strips. 


Figs.  3044-3048 


ACCESSORIES. 


439 


RELAYS 


UNION   9C   NEUTRAL  TYPE  RELAY. 

This  relay  is  manufactured  by  the  Union  Switch  &  Signal 
Company.  Porcelain  is  used  everywhere  as  an  insulator,  except 
In  the  case  of  the  coils  and  a  block  carrying  the  coil  terminals. 


Fig.  3046.     Union  Model  gC  Neutral  Relay. 


Fig.  3044.   Model  gC  Relay.   2  Front  and  2  Back  Points. 


Fig.  3047.     Style  "H"  Shelf  Type  Neutral  Relay. 
Front  View.     Hall  Signal  Company. 


Fig.    3045. 
Points. 


Model    pC    Relay.      3    Front    and    2    Back 
The  Union  Switch  &  Signal  Company. 


The  coils  are  wound   on  hard   rubber  spools,   easily   removable 
from  the  cores  without  disturbing  the  adjustment  of  the  points. 
There  are  no  concealed  insulating  bushings.    The  relays  pass 
a  ground  test  of  5,000  volts  before  leaving  the  shops. 

HALL   NEUTRAL   RELAY. 

Fig.  3047  shows  the  style  "H"  neutral  relay  made  by  the  Hall 
Signal  Co.  It  is  glass-enclosed  with  metal  base  and  "bakelite" 
top.  The  top  or  magnet  support,  being  made  of  "bakelite, ' 


Fig.   3048.     Bottom  View,  Style  "H"  Relay. 
Signal  Company. 


Hall 


440 


ACCESSORIES. 


Figs.  3049-3052 


dispenses  with  the  use  of  insulating  bushings  or  washers  at 
binding  posts.  By  a  simple  device,  consisting  of  a  square 
washer  and  snap  ring,  the  binding  posts  carrying  the  front 
graphite  contacts  are  locked  in  position  and  cannot  be  turned 
without  first  removing  the  glass  case. 

The  most  important  feature  of  the  style  "H"  relay  lies  in 
the  use  of  a  flexible  silver  gauze  for  the  lower  portion  of  the 
front  contacts.  This  construction  provides  a  contact  of  uni- 
formly low  resistance. 


There  have  been  many  instances  recorded  where  a  relay, 
especially,  of  the  shelf  type,  has  been  placed  at  such  an  angle 
as  to  maintain  a  circuit  through  the  front  contacts  with  the 
magnets  de-energized. 

This  condition  has  also  been  produced  by  the  relay  post 
being  bent  or  thrown  out  of  position  by  a  storm  or  otherwise. 
With  the  "Everett"  contact  no  such  dangerous  condition  can 
exist. 

The  mercury  cup  is  attached  to  the  roar  binding  posts  of  the 


Fig.    3049.      Style    "H"   Wall    Type    Relay  with    Gauze 
Contacts.      Hall    Signal    Company. 


Relay    with    "Everett"    Mercury    Contacts. 
Hall   Signal    Company. 

relay,  find  is  connected  in  series  with  the  contacts.  When, 
through  carelessness  or  other  cause,  the  relay  is  placed  at  an 
angle  sufficient,  to  close  the  front  contacts,  the  mercury  moves 
by  gravity  to  the  side  of  the  cup  and  out  of  range  of  the 
platinum  wire  conm-H  crs.  thus  opening  the  circuit  and  pre- 
venting a  false  clear  signal. 


Fig.   3050.      Style   "H"   Shelf  Type   Relay.     Top   View. 
Hall  Signal  Company. 

The  large  area  of  the  silver  gauze  in  contact  with  the 
carbon  affords  great  carrying  capacity,  and  experience  has 
shown  that  with  this  arrangement  it  is  impossible  for  a  fused 
contact  to  maintain  a  closed  circuit. 

This  relay  is  built  in  both  the  wall  and  shelf  type  and  in 
varying  sizes  up  to  eight  front  and  eight  back  contacts. 


RKF.AY  WITH  "EVERETT"  MERCURY  CONTACTS. 
Fig.  3051  shows  a  relay  made  by  The  Hall  Signal  Co.  having 
"Everett"  mercury  contacts.  These  contacts  are  used  for 
breaking  a  front  contact  on  a  relay  when  the  front  contact 
is  held  closed  without  current  by  the  tipping  or  improper 
position  of  the  instrument. 


Fig.  3052.     Type  "B"  Circular  Track  Relay,  Four  Front 

and    Four    Back    Contacts.      United    Electric 

Apparatus  Company. 


Figs.  3053-3058 


ACCESSORIES. 


441 


Fig.   3053.      Union    Model   9    Neutral    Relay. 


Fig"-   3°54-     Union    Model   9    Neutral    Relay 


Figs.  3055-3056.     Union   Model   iC  Relay. 


Figs.  3057-3058.     Model  2  Relay,  Neutral  Type;  Inverted     View,   and    Section.     The   Union   Switch   &  Signal 

Company. 


442 


ACCESSORIES. 


Figs.  3059-3063 


Fig-  3059-     Plan  of  Union  Model  i,  Neutral  Type  Relay. 


Fig.  3060. 


Sectional  View  of  Union   Model   I,   Neutral 
Type  Relay. 


Fig.  3061.  Neutral  Enclosed    Relay.    Ameri- 
can Railway  Signal  Company. 


Fig.  3062.     Neutral  Enclosed  Relay 

American  Railway  Signal 

Company. 


Fig.    3063.      Type    D    Track    Relay. 
United  Electric  Apparatus  Co. 


Figs.  3065-3069 


ACCESSORIES. 


443 


G.     R.     S.     UNIVERSAL    DIRECT     CURRENT    RELAYS. 

In  the  G.  R.  S.  Co.'s  Model  9  relays  and  indicators,  essentially 
the  same  parts  are  used,  the  magnet  cores,  yoke,  armatures, 
Insulations,  binding  posts,  contacts,  etc.,  being  standard  for  all 
the  devices  of  this  line.  Figs.  3065  and  3066  show  views  of 
the  four  and  six  point  Model  9  Form  A  relays.  The  Model 
9  Form  A  is  also  made  in  the  wall  type  relay,  as  shown  by 
Fig.  3068. 

The  Model  9  Form  B  is  provided  with  "non-freezing"  con- 
tacts, as  a  protection  against  lightning  or  other  heavy  cur- 
rents. This  feature  consists  of  two  semi-interlocked  platinum 
contacts  so  arranged  in  series  that  should  the  working  contact 
be  frozen  the  secondary  contact  will  be  opened  and  locked 
open. 

The  Model  9  Form  C  relay,  illustrated  by  Fig.  3069,  is 
constructed  so  that  the  front  contacts  may  be  removed  for 
the  purpose  of  cleaning  them  without  disturbing  any  of  the 
other  parts. 

In  the  Model  9  polarized  relay  the  neutral  and  polar  magnetic 
circuits  are  entirely  independent,  the  one  not  having  any  in- 
fluence on  the  other. 


Fig.  3067.     Model  19  A.  C.  Relay,  lo-Way.     General  Rail- 
way  Signal   Company. 


Fig.  3065.     Universal  D.  C.  Relay,  Model  g,  Form  A,  Four- 
Way. 


Fig.  3068.    Universal  D.  C.  Relay,  Model  g,  Wall  Type, 
4-Way.     General  Railway  Signal  Company. 


Fig.    3066.      Universal    D.    C.    Relay,    Model    g,    Form   A,       Fig.  3069.     Universal  D.  C.  Relay,  Model  9,  Form  C.  (Re- 
Six-Way.     General  Railway  Signal  movable  Contacts.)     4- Way.     General  Railway 
Company.  Signal  Company. 

Figs.    3065-3069.      Relays.      General    Railway    Signal    Company. 


444 


ACCESSORIES. 


Fi 


gs.  3070-3074 


Fig.   3070.     Type   "E"   Enclosed   Line   Relay.     United    Electric 
Apparatus    Company. 


Fig.     3072.      Enclosed     Neutral     Relay. 
Railroad  Supply  Company. 


Fig.     3073.     Sectional     View     6f     Relay 
Shown    in    Fig.    3072. ' 


Fig.  3074.    Neutral  Relay.     Railroad  Suj 
ply  Company. 

Names    of    Parts,    Neutral    Relay;    Fig 
3074- 


Fig-  3071.     Type  "H"  Enclosed  Relay.     United  Electric  Appa- 
ratus Company. 


Armature 
Armature  Lever 
Spring  Support 
Contact  Spring 
Countenveight 
Contact  Block 


8 

9 
10 


Magnet 

Base 

Flexible    Connec 

tion 
Trunnion    Sup 

port 


Figs.  3075-3078 


ACCESSORIES. 


445 


Fig-.   3075.     Inverted   View,    Showing  Arrangement   of 

Neutral    Armature    and    Contacts,    Model    I 

Relay  Polarized   Type. 


Fig.    3076.      Inverted    View    Showing   Arrangement    of 

Polarized  Armature  and  Polar  Contacts.     Model  i 

Relay  Polarized  Type. 


Fig.    3078.     Neutral    Relay.      Railroad    Supply 
Company. 


The  G.  R.  S.  Model  9  polarized  relay  is  of 
the  same  size  and  construction  as  the  neu- 
tral relay  except  for  the  addition  of  a  per- 
manent magnet  and  polarized  armature 
with  the  necessary  contacts.  The  polar- 
ized armature,  one  end  of  which  swings 
between  the  neutral  pole  pieces,  is  sus- 
pended below  the  permanent  magnet.  The 
principles  involved  in  its  operation  are 
the  same  as  in  the  case  of  the  Union 
Universal  relay,  Figs.  3075-3077. 


Fig.  3077.     Model  i  Relay.     Polarized  Type.    The  Union  Switch  & 
Signal   Company. 


446 


ACCESSORIES. 


Figs.  3079-3083 


HALL     POLARIZED     RELAY. 

The  neutral  polar  relay  of  the  Hall  Signal  Co.,  shown  In 
Fig.  3079,  is  of  the  glass-enclosed  type,  and  consists  of  a 
neutral  and  a  polarized  armature,  with  magnets  and  binding 
posts  mounted  on  a  bakelite  top. 

The  polarized  armature  is  a  permanent  magnet,  horizontally 
pivoted  at  center  and  provided  at  each  end  with  either  one 
or  two  silver  or  platinum  contacts  as  desired. 

The  neutral  armature  carries  from  one  to  four  contact  fin- 
gers, with  silver  gauze  front  contacts,  and  either  silver  or 
platinum  back  contacts. 

Base,  glass  case  and  top  are  held  together  by  four  corner 
screws,  two  of  which,  located  diagonally  opposite,  are  provided 
with  means  for  attaching  the  Hall  metal  seal. 

The  relay   top  is  made  of  bakelite. 


Fig-    30/9.     Neutral    Polar    Relay,    Front   View.      Hall 
Signal  Company. 


Fig.  3082.    Rear  View  of  Three-Point  Quick  Release 

Relay.     American  Railway  Signal 

Company. 


Fig.  3080.     Neutral  Polar  Relay,  Bottom  View. 


Fig.  3081.     Three-Point  Quick  Release  Relay,  Front 
View.     American  Railway  Signal 
Company. 


Fig.  3083.    Two-Point  Heavy  Current  Relay  with  Blow- 
out Magnets.    American  Railway  Signal 
Company. 


Figs.  3084-3087 


ACCESSORIES. 


447 


Fig.  3084.    Two-Point  Heavy  Current  Relay  with  Blow- 
out  Magnets.     American    Railway 
Signal    Company. 


Fig.    3085.      Polarized    Relay.      Back   View.      American 
Railway  Signal  Company. 

rXIOX  GALVANOMETER  TYPE  A.  C.  TRACK  RELAY. 

Fig.  3087  shows  a  two-element  relay,  designed  originally  for 
use  on  electric  roads.  When  used  on  steam  roads,  the  mechanical 
•construction  is  the  same,  the  winding  only  being  changed. 

The  two  large  coils  are  the  field  winding  and  are  connected 
to  a  local  source  of  alternating  current.  The  moving  coil  is 
the  armature  winding  and  is  connected  to  the  track.  The  shaft 
•carrying  the  moving  coil  is  connected  by  cranks  and  a  link  to 
-a  second  shaft,  which  carries  (lie  contact  springs. 

To  operate  the  relay  it  is  necessary  to  have  current  flowing 
to  both  windings,  and  these  currents  must  be  in  a  certain 
direction  relative  to  each  other.  In  case  direct  current  flows 
through  the  armature,  it  cannot  operate  the  relay,  since  the 
•fields  are  energized  with  alternating  current. 

The  relay  contains  tio  iron  in  its  magnetic  circuit  and  there- 
fore it  cannot  be  held  closed  by  direct  current  flowing  through 
the  armature  after  the  alternating  current  has  been  shunted 
off.  If  the  polarity  of  adjacent  track  circuits  is  reversed,  cur- 


Fig.     3086.       Front     View     of     Polarized     Relay.       Two 
Neutral  Front  and  Back  Contacts,  Two  Polar- 
ized Front  and  Back  Contacts.     American 
Railway  Signal  Company. 

rent  coming  from  the  adjacent  track  circuit  in  case  the  insulated 
joints  are   broken   down,   will   tend   to   open   the   relay   contacts. 

The  clearances  in  the  relays  are  large. 


UXIOX    RADIAL   COXTACT   RELAYS. 

The  advantages  of  the  radial  contact  system  are  accessibility 
of  binding  posts  and  the  opportunity  which  the  arrangement 
of  the  contact  system  permits  for  inspection  of,  and  easy  access 
to  the  operating  mechanism.  The  second  characteristic  is  espe- 
cially desirable  when  the  operating  mechanism  involves  small 


Fig.    3087.     Galvanometer    Type    A.    C.    Relay. 
Switch  &  Signal  Company. 


Union 


clearances  between  stationary  and  moving  parts,  such  as  are 
necessary  for  high  economy  of  power  consumption  in  the  induc- 
tion motor  type  of  relay. 

The  divisions  of  the  case  and  the  porcelain  contact  carrier 
are  assembled  with  dust-proof  gaskets,  but  can  be  readily  taken 
apart,  this  making  it  easy  to  make  the  changes  in  points 
necessary  to  get  any  desired  combination  of  front  and  back 
contacts,  or  to  make  renewals  of  wearing  parts. 

By  employing  porcelain  for  the  mounting  of  the  contact  posts 
and  for  the  driving  piece  which  imparts  motion  to  the  movable 
parts  of  the  contacts,  the  radial  system  avoids  the  use  of  con- 
cealed bushings.  The  binding  posts  are  non-turning  and  com 


ACCESSORIES. 


Figs.  3088-3091 


ply  with  Railway   Signal   Association   requirements.     The   radial 
contact  relay  can  be  used  as  either  a  track  or  line  relay. 

The  holding  clear  device  is  placed  in  a  perfectly  accessible 
position,  with  its  movable  members  housed  within  a  sealed  com- 
partment, secured  to  the  frame.  In  other  words,  the  magnet 


Fig.  3088.     Induction   Motor  Type   Radial   Contact   Relay. 
The  Union  Switch  &  Signal  Company. 

and  controlling   elements   of  the  clutch,   or  slot,  are  stationary, 

easily  detached,  accessible,  and  are  out  of  reach  of  the  weather 

during    inspection    or    other    attention     to    the  mechanism    in 
inclement  weather. 


to  arrest  the  momentum  of  the  motor ;  the  application  being 
also  accompanied  by  a  quick  interruption  of  the  motor  circuit. 
This  arrangement  insures  the  interruption  of  the  motor  current 
before  the  brakes  become  effective. 

When  the  signal  returns  to  stop,  the  brake  Is  positively  re- 
leased and  the  break  In  the  motor  circuit  is  again  established. 
In  the  three-position  type  of  mechanism  a  magnetic  clutch  is 
employed  instead  of  a  mechanical  brake.  This  clutch  Is  ener- 


Fig.  3090.     Radial  Relay  Induction  Motor  Type.     The 
Union  Switch   &  Signal   Company. 

gized  with  the  motor  and  causes  the  motor  pinion  to  revolve 
with  the  armature  positively  at  such  times.  When  current  to 
them  Is  interrupted,  the  armature  is  disengaged  from  the  pinion, 
and  the  armature  is  thus  permitted  to  come  to  rest  at  will, 


Fig.  3089.     Radial  Contact  Relay  A.  C.  Jaw  Type.     The 
Union  Switch   &  Signal  Company. 

In  the  two  position  forms  of  this  signal  a  simple  a.  c.  or 
d.  c.  motor  is  used  with  a  mechanically  actuated  brake,  which, 
as  the  signal  is  moved  to  the  clear  position.  Is  suddenly  applied 


Fig.  3091.     Radial  Type  Relay  A.  C.  Jaw  Type. 
Switch  &  Signal  Company. 


Union 


while  the  pinion  and  the  other  gearing  of  the  signal  come  to 
rest  practically  instantaneously.  This  latter  effect  is  assured" 
and  the  backward  movement  of  the  gearing  by  the  signal  is  pre- 
vented by  the  release  of  the  motor  clutch  acting  as  a  brake 
upon  the  pinion  shaft. 


ELECTRO-PNEUMATIC    RELAY. 

The  electro-pneumatic  relays  illustrated  are  of  the  types 
installed  on  the  Pennsylvania  Tunnel  &  Terminal  Railroad. 
The  energizing  of  magnet  F  forces  the  valve  stem  of  valve  G 
up  and  permits  air  to  pass  through  piping  27  to  bottom  of 
cylinder  C.  driving  piston  3  up  and  in  turn  raises  contact 
block  E,  and  by  so  doing  makes  contact  with  springs  on  contact 
spring  board  D.  The  de-energizing  of  magnet  F  permits  the 
air  to  escape  through  valve  G,  and  by  means  of  the  coll 
springs  12  the  contacts  are  forced  open.  With  this  relay  the 
number  of  contacts  and  combinations  are  practically  unlimited. 


Figs.  3092-3096 


ACCESSORIES. 


449 


Fig.  3093.     Heavy  Current  Relay  (Magnetic 
Blow-Out).     General   Railway  Sig- 
nal Company. 


Fig.    3094.      Circuit    Diagram    for 
Fig.  3097- 


Fig.  3092.     Type  "E"  Relay  A.  C.  or  D.  C.     United  Electric 
Apparatus   Company. 


Fig.    3095.      Relay    in    Iron    Relay 
Box.     Bryant  Zinc  Company. 


Fig.  3096.     Type  "E"    Polarized    Relay.     United    Electric  Apparatus 

Company. 


450 


ACCESSORIES. 


Figs.  3097-3103 


PLAN    VIEW 


10        38        11          26          25 


SECTIONAL.     FRONT      VIEW 


Figs.   3097-3098.     Electro-Pneumatic   Relay.      The    Union 
Switch    &   Signal    Company. 


Figs.  3099-3100.  Electro- Pneumatic  Relay  with  A.  C.  Jaw 

Type    Magnet.     The    Union    Switch    &   Signal 

Company. 


PLAN    VIEW 


SECTIONAL    FRONT    VIEW 


END     VIEW 


Figs.  3101-3102.  Electro-Pneumatic  Relay  with  A.  C.  Jaw 

Type  Magnet.     The  Union  Switch  &  Signal 

Company. 


Fig.  3103.     Universal   Polyphase  Wall  Type  Relay, 

Model  2,  Form  B.     General  Railway 

Signal  Company. 


Figs.  3104-3107 


ACCESSORIES, 


RELAY  HOUSINGS,  MOUNTINGS  AND  CABLE  POSTS 


Fig.  3104.     Iron  Relay  Box  Mounted  on  Iron  Stub  Post 
ana  Concrete  Foundation.     Bryant  Zinc  Company. 


Fig.  3106.    Relay  Box  and  Cable  Post.    Northern  Pacific. 
General    Railway    Signal    Company. 


FRONT    VIEW 
COVER     REMOVED 


SECTIONAL    SIDE    VIEW 


Fig.  3105.     Cable  and  Relay  Box  Post;  and  Cable,  Relay, 

and   Indicator   Post  with  Indicators.     Hall  Fig.  3107.    Vertical  Relay  and  Terminal  Case.    The  Union 

Signal  Company.  Switch   &   Signal   Company. 


452 


ACCESSORIES. 


Figs.  3108-3116 


Fig.  3109.     Relay  Box,  Indicator,  and  Cable  Post.    North- 


T-..  o      o    v  u    T  j-  j   /•«  vi     «  -NT     it.  ern   Pacific.     General  Railway     Signal     Company. 

Fig.   3108.     Switch   Indicator  and   Cable   Post.     Northern 

Pacific.     General  Railway  Signal  Company. 


< 

y 


-=,  4 


------  :_r^r  -  ±"1»T "_-:  r_J 


•-JF 


Figs.  3113-3114.    Iron  Relay  Box.     Hall  Signal 
Company. 


SCtspaS' 


Figs.  3110-3112.    Standard  Relay  Box  for  Four  Relays. 
Hall  Signal  Company. 


Figs.  3115-3116.     Iron  Relay  Box  Complete.     Hall 
Signal  Company.  . 


Figs.  3117-3130 


ACCESSORIES. 


453 


Figs.    3117-3118.      Iron    Relay    Box    Complete    for   Three- 
Inch  Pipe.     Hall  Signal  Company. 


Fig.  3122.     Grid  Resistance  and   Polyphase  Relays.     New 
York  Central.    General  Railway  Signal  Company. 


Figs.    3119-3120.      Iron    Relay    Box    Complete    for    Three- 
Inch  Pipe.     Hall  Signal  Company. 


Fig.  3123.     Model  9  Relays  and  Relay  Box  on  Signal  Post. 

Northern  Pacific.     General  Railway  Signal 

Company. 


'  =   \  / 

I     JL 


Fig.  3121.     Relays   and  Relay   Box.     Hall    Signal  Figs.    3124-3130.       Cable    Posts    with    Relay    Boxes    and 

Company.  Indicators. 


454 


ACCESSORIES. 


Figs.  3131-3136 


Fig-  3135-  Relay  Box  and 
Cable  Post.  [When  Mounted 
on  Double  Battery  Chute, 
Same  Attachments  are  used 
as  in  Fig.  3136  below.]  Bryant 
Zinc  Company. 


Fig.   3131-     Iron   Relay   Box  with   Uni- 
versal Relays  and  Lightning  Ar- 
resters in  Place.    The  Union 
Switch  &  Signal  Company. 


Fig.    3I33-      Iron    Relay    Box    for 

Crossing  Bell  Post.   The  Union 

Switch  &  Signal  Company 


Fig.  3I34-     Wooden   Relay  Box  with 
Fig.    3132.      Relay    Box   and    Battery  Frost    Door.      Railroad    Supply 


Chute.     Great  Northern. 


Compahy. 


Fig.     3136.        Relay      Box 
Mounted  on   Double  Battery 
Chute.      Bryant    Zinc    Com- 
pany. 


Figs.  3I37-3M7 


ACCESSORIES. 


455 


Figs.  31.37-3138. 
Cast  Iron  Instrument  Case 
The  Union  Switch  & 
Signal  Company. 


Figs.    3139-3143-      Single    Cast    Iron    Battery 
Chute  with  Cast  Iron  Post  and  Relay 
Box.     Union    Switch    &   Signal 
Company. 


Figs.   3146-3147.      Double    Iron    Relay 
Box.     General  Railway  Sig- 
nal Company. 


Figs.  3I44-3MS.  Sin- 
gle Iron  Relay  Box 
Mounted  on  Iron 
Pipe  Post,  with 
Cast  Iron  Base. 
General  Railway 
Signal  Company. 


456 


ACCESSORIES. 


Figs.  3148-3155 


I 

A 

\ 

\ 

^       0 

O*^,  .  i 
^ 

i^tt^/       1 

\ 

\  1— 

1          L 

\ 

0  T    ^ 

\ 

-^j     \ 

\ 

-^"-:-,; 

U  —  , 

=rfTTfe=  LJ. 

Figs.  3148-3149.     Two  Interlocking  Relays  in  Case.     Railroad  Supply 

Company. 


Fig.  3150.     Relay  Box. 

Railroad  Supply 

Company. 


Fig.  3751.     Double  Iron  Relay  Box  on 
Iron  Pipe  Post.     General  Railway 
Signal   Company. 


Fig.  3152.     Reinforced 
Cement  Relay  Box  Post 
and  Foundation.       C.    F. 
Massey   Company. 


-    3153-      Cable    Post 
Bryant  Zinc  Com- 
pany. 


Fig.  3154.  Cable 
Post  and  Relay  Box. 
Bryant  Zinc  Company. 


Fig-  3I5S-     Reinforced 
Cement  Relay  Box,  Post 
and    Foundation.      C.    F. 
Massey  Company. 


Figs.  3156-3172 


ACCESSORIES. 


457 


1 I 


Figs.  3156-3162.     Indicator  and  Relay  Boxes  Mounted  on  Cable  Posts.     The  Union  Switch  &  Signal  Company. 


Sie/nalFbtt 


Batrery  Cftvte 


Figs.    3165-3166.      Iron    Relay    Boxes    and   Posts.     The 
Union    Switch    &   Signal    Company. 


Figs.  3163-3164.    Relay  Boxes  and  Cable  Posts  Mounted      Figs.  3167-3172.    Relay  Boxes  and  Stub  Posts  Mounted 

on  Battery  Chutes.     General  Railway  Signal  on  Battery  Chutes.     General   Railway  Signal 

Company.  Company. 


ACCESSORIES. 


Figs.  3173-3190 


Fig.  3173. 


Fig.  3180. 


Fig.  3181. 


Fig.  3174- 


Fig.  3I75- 


Fig.  3176. 


Fig.  3177.  Fig.  3178. 

Figs.  3I73-3I79-     Indicator  and  Relay  Boxes  Mounted  on 

Iron  Posts  and  Iron  Foundations.    Union  Switch  & 

Signal    Company. 


Fig.  3I79- 


Fig.  3182.  Fig.  3183.  Fig.  3184. 

Figs.   3181-3184.     Relay    Boxes,    Pole    Fittings,    and 
Attachments    and    Combinations.      General 
Railway  Signal  Company. 


Figs.    3185-3190.      Cable      Posts,      Indicators,      and    Relay 

Boxes.     General  Railway  Signal 

Company. 


Figs.  3191-3207 


ACCESSORIES. 


459 


Figs.   3193-3194.    Malleable   Pole   Clamps 


Figs.  3191-3192.     Bracket     Support     for 
Relay  Bell  and  Indicator. 


Figs.  3195-3196.     Two  Piece  Base  Castings. 


Figs.  3197-3199.     Relay  Box  Post. 


Fig.  3200.     Pinnacle. 


Figs.    3203-3204.     Pipe    Sockets. 


Figs.  3201-3202.     One  Piece  Base  Cast- 
ing. 


Fig.  3207.     Assembly  for  Battery  Chute 
Figs.    3205-3206.    Pipe    Sockets.  and  Relay  Box. 


Figs.  3191-3207.     Relay  Box  and  Cable  and  Signal  Post  Fittings.     Railroad  Supply  Company. 


460 


ACCESSORIES. 


Figs.  3208-3219 


Fig.  3208-3215.     Relay  Box,  Stub  Pole,  Foundation,  Trunking  Connections  and  Details.     Atchison,  Topeka  &  Santa  Fe. 


Fig.    3216.     Case    Wiring.      Staggered    Home    Signals. 
Oregon  Short  Line. 


Fig.    3217.     Case    Wiring.      Distant    Signals.      Oregon 
Short  Line. 


Figs.  3218-3219.     Case  Wiring.     Home  Signals.     Oregon  Short  Line. 


Figs.  3220-3223 


ACCESSORIES. 


461 


norm,  -f-  Dai  /  j    {•; 

n   n   n   n<Ti!i 


nOTE     Chute  tv/rcs  /o  be  */z 
flexible,   copper  from  E/evator  -fa 
Terminal   B/ocJis . 
Track  Wires  to  be,  */O  so//cf  cop- 
per from   Root  Lings  to    Termi- 
nal E>/ochs  . 

For  Leads  from  Term'/  £>/ocHs 
to    Be/ay  use  "/4f/eA/b/e 
core/  with    Shain's  Termina/s 
on  ends  ,  use  fG "  /engfhs  on 
bach  pos  ts  &  ZO  "  /enc/ths  on 
a//  others. 

/Tee/?  p/pes  in  grouncJ  at 
/ccrst  4-  "  crpcrrt. 


rforma/  - 
Fig.  3220.     Case  Wiring,  Double  Track  Polarized  Relayed  Section.     Oregon  Short  Line. 


S/7C/T-I//EW    - 


-t*-'-  r  ^T^^ 
f, --SH& 


l^H^, 

i .  FROnr  VIEWS 

IJ&iiZKS?9  "*"*•  ^2-,  a 


JSW 


Fig.  3221.     Case  Wiring.     Relay  Box  for  Distant   Sig-       Fig.    3222.      Case    Wiring.      Relay   Box    for    Staggered 
nal.     Oregon  Short  Line.  Home  Signals.     Oregon  Short  Line. 


UUUULJ/UUUUU 

Lrtormal   Bail 

'/z  'pipes  in  ioundat 


SLOW  acririG 

BELAY.   — 


en   all  Mires   to  bach  of  Termi- 
'a  I  Board,  using  strips  of  leather. 

TracH  yvires  to  be  "  1O  solid  copper 
Wires  -from  Terminal  B/ocfts  to  Me- 
chanism    to   be  *IO  soli'd  copper. 
Dun  *IZ  flexible  from  chute  e/em 
tor  to   term  .  board  in  tapper  case. 
For  Leads  to  Belays  &  Po/e  Chan- 
ger use  "14  -f/ef/ble  cord  ZO  * 
long  nith  5hain  j  Term,  on  bothendj- 
Wires  ore  shown   separate  in  order 
to  trace ,  but  ahou/d  be,  cabled 
rfherc  practicaf.  ~ 


urtDERSIDE    OF  QELPY  S. 


Fig.  3223.     Case  Wiring.     Double  Track  Polarized  Two-Arm  Signal.     Oregon  Short  Line. 


462 


ACCESSORIES. 


Figs.  3224-3263 


SIGNALS  AND  FITTINGS 


Names  of  Parts;  Figs.  3224-3263. 


Low  Pot  Signal 
High   Pot  Signal 
One-Arm  Dwarf  Signal 
Two-Arm  Dwarf  Signal 
Three-Arm  Dwarf  Signal 
One-Arm  Bridge  Signal 
Two- Arm  Bridge  Signal 
Three-Arm  Bridge  Signal 
One-Arm  Ground  Signal 
Two- Arm   Ground  Signal 
Three-Arm  Ground  Signal 
One-Arm'     Elevated       Railroad 

Signal 
Two-Arm      Elevated      Railroad 

Signal 

One-Arm  Cantilever  Signal 
Two-Arm  Cantilever  Signal 
Three-Arm  Cantilever  Signal 
One-Arm  Cantilever  Signal 
Two-Arm   Cantilever   Signal 
Three- Arm  Cantilever  Signal 
One-Arm  Bracket  Signal 
One-Arm  Bracket  Signal 
One-Arm    Bracket    Signal    with 

High  Bracket  Mast 
One-Arm    Bracket    Signal    with 

High  Bracket  Mast 
Two- Arm  Bracket  Signal 
Two-Arm   Bracket    Signal,    One 
High  and   one  Low  Bracket 
Mast 

Two-Arm  Bracket  Signal,  One 
High  and  One  Loiv  Bracket 
Mast. 

Tzvo-Arm  Bracket  Signal 
Tzvo-Arm  Bracket  Signal 
Two-Arm^  Bracket  Signal,  with 

High  'Bracket  Mast 
Two-Arm   Bracket   Signal,   with 

High  Bracket  Mast 
Three-Arm  Bracket  Signal 
Three-Arm  Bracket  Signal 
Three-Arm  Bracket  Signal,  with 

One  High  Bracket  Mast 
Four-Arm  Bracket  Signal,  with 

One  High  Bracket  Mast 
Four-Arm  Bracket  Signal,  with 

One  High  Bracket  Mast 
Tzvo-Arm  Bracket  Signal 
Two-Arm   Bracket   Signal,   with 

One  High  Bracket  Mast 
Three-Arm  Bracket  Signal 
Three-Arm  Bracket  Signal,  zvith 

One  High  Bracket  Mast 
Four-Arm  Bracket  Signal 


36 


37 

Figs.  3224-3263. 


38  39 

Typical  Arrangements  of  Signals. 


Figs.  3264-3289 


ACCESSORIES. 


463 


41  Two-Arm  Bracket  Signal 

42  Two-Arm   Bracket   Signal,  with 

One  High  Bracket  Mast 

43  Three  Arm  Bracket  Signal 

44  Three-Arm  Bracket  Signal,  with 

One  High  Bracket  Mast 

45  Four- Arm  Bracket  Signal 

46  Tzvo-Arm,    Three-Bracket   Mast. 

Lattice  Post  Bracket  Signal 

47  Two- Arm,   Three-Bracket  Mast, 

Lattice  Post  Bracket  Stgnal 

48  Three-Arm,  Three-Bracket  Mast. 

Lattice  Post  Bracket  Signal 

49  Three-Arm,  Three-Bracket  Mast, 

Lattice  Post  Bracket  Signal 


47  48  49 

Figs.  3264-3273.     Typical  Arrangements  of  Signals.     Union  Switch  &  Signal   Company. 


Bridge   Signals. 


Base     of     Mast     Signals. 


Bracket   Signals.  Pipe  Connected  Interlocking  Signals. 

Figs.  3274-3289.     Typical  Arrangements  of  Signals.     General  Railway  Signal  Company. 


464 


ACCESSORIES. 


Figs.  3290-3301 


Model  "2A"  Direct  Connected  Signals.  Model  "2A"  Base  of  Mast  Signal. 

Figs.  3290-3295.     Typical  Arrangements  and  Assemblies  of  Signals.     General   Railway   Signal   Company. 


Model  "2A"  Signals  with  Base  of  Mast  Mechanism  and  Battery  Case. 


Model  "2A"  Base  of  Mast  Signal. 


Figs.  3296-3301.    Typical  Arrangements  and  Assemblies  of  Signals.    General  Railway  Signal  Company. 


Figs.  3302-3318 


ACCESSORIES. 


465 


PLAN  VIEW  Or  BASE 


B 


-5-0 

HONT  VKW 


SIGNAL    HAVING 
CAST  STEEL  BASE 


k-5-0- 
FHOHT  view  or  BASE 
SIGNAL  HAVING 
CAST  IRON    BASE 


Four-Arm   Mechanical    Bracket    Signal.     Figs.  3306-3311.     R-  S.  A.  Standard   Ladders  for  Pipe 
Union  Switch   &  Signal  Company.  Signal   Posts. 


Figs.  33I2-33I3. 
Types  of  Two-Light  Semaphore  Castings. 


ig-  33M-     R-  S.  A.  Standard  Base       Fig.   3315.     R.   S.   A.    Standard   Base   for 
for  Six-Inch  Signal    Post.  Bridge  Signal  Masts. 


Figs.    3316-331^-      R-    S.    A. 
Standard    Top    of 
Ladder  Details. 


466 


ACCESSORIES. 


Figs.  3319-3327 


Figs.    3320-3321.      Double,    Three- 
Position,    oo-Deg.    Train   Order    Sig- 
nal;   Iron    Pipe    Post,    Pipe    Con- 
nected,    with     "Universal"     Sema- 
phore Casting. 


Fig.  3319.  Double,  Two- Position 
Train  Order  Signal;  Post  Made  of 
Rails,  Pipe  Connected,  Using 
Standard  Semaphore  Castings  for 
Both  Arms.  Chicago  &  North- 
Western. 


Fig.  3322.      Double,  Two-Position, 
po-Deg.       Train       Order      Signal; 
Wooden  Post,  Wire  Connected. 


flPPLICflTION 


Figs.  3325-3326.   Double,  Two-Posi- 
tion,   ox>-Deg.    Train    Order    Signal, 
Wooden     Post,     Pipe     Connected, 
with  "Universal"  Semaphore  Cast- 
ing. 


3  0  Anchor 
Bo/ts 


K  -3  '<?- 

Figs.       3323-3324-       T  w  o  -  A  r  m 
Double,     Two-Position     Train     Or- 
der Signal;   Iron    Pipe  Post,   Pipe 
Connected.     New  York  Central  & 
Hudson  River. 


Fig.    3327.       Double,     Three-Posi- 
tion,   75-Deg.    Train    Order    Signal; 
Iron  Pipe  Post,  Pipe  Connected. 


Figs.  3328-3340. 


ACCESSORIES. 


467 


•jXIO     US.STD.TH 


for?   £. 


Fig.  3328.     "U"  Bolt  for 
Semaphore  Bearing. 


t3"»  SEE  PLAN  NO.  1093  FOR  DIAGRAM  Of  CLEARANCES 


Fig.  3330.     Semaphore  Spectacle   (Design  B). 


k.A|--.S'-H 

U£  —  ___  _ 

Fig.  3329.     Semaphore  Spectacle   (Design  A). 


USE  TWO,  |  X  5;  BOLTS  FOR  CLAMPING  TO 
iST  WHEN  USED  IN  CONNECTION  WITH 


j _2§.'Y   mfCO*}1  SEMAPHORE  BEAR1N6. (SEE  NO.I082   ISSUE:l9ll) 

-jK    •!   J 


foff  Law/*  BRACKET  uvHEffe  SrtHsseReD  L/GHT  is  USED. 

"igs.  3331-3333-     Clamp  for  Semaphore  Bearing. 


BACK  HALF. 


'V'BOLT. 


USE  TWO    2  I  6j  BOLTS    WHEN  ASSEMBUN6    FRONT    AND   (AW    HALF 


—BACK   OF  SPECTACU 
FRONT  OF  BEARIN6 


CLEARANCES  . 

'HREE -FOURTHS  INCH  ( J°)  MINIMUM 
CLEARANCE  SHALL  BE  MAINTAINED 
BETWEEN  THE    SEMAPHORE  BEARM6 
AND  ANY    PASSINE    PART  OF  THE 
SEMAPHORE   SPECTACLE. (EXCEPT  HUB) 


(l>.)  ONE  I»CH(0  MINIMUM  AND  TWO  INCH 

(2*)  MAXIMUM  CLEARANCE  SHALL' ee 

MAINTAINED  BETWEEN  THE    LAMP 
AND   ANY    PASSIM  PART  OF  EITHER 
FRONT  OR  BACK    SEMAPHORE 
SPECTACLES 


CONE  Ft*  |  Wl 


FRONT    HALF. 


-  3334-    Diagram  of  Spectacle  Clearance.  Figs.  3335-3340.    Clamp  for  Base  of  Ground  Signal  Masts. 

Figs.    3328-3340.      Railway   Signal    Association    Standards. 


468 


ACCESSORIES. 


Figs.  3341-3342.    Blades  for  Upper  Quadrant  Signals. 


APPLICATION   FOR  FIXED  ARMS 


APPLICATION  FOR  0    TO   45   TRAVEL . 


usi  oe.UiJ  BOLT 

Mt  ro  jAuJ*OB€ 


*  14. MAX.    MSTAL  CUAT.    H-  6  — 


Fig-  3343-     Blade  for  Upper  Quadrant  Signal. 


COM  TOKJBOLT 


«• 

UX  TWO,  §  "U-  801.TS  FOB   O.AMPIHG  TO  M»ST. 
USt  ONE  'U'  BOLT  W>  TWO,  l\  si"  BOLTS  W 

ew»tmo«  WITH  CLAMP  FOB  UCMP  W»CKFT.(SE: 


WHEN    USED   « 
(SEE  NO.I083.IS5UE.-ISII) 


Figs.  3352-3356.     Semaphore  Bearing. 


APPLICATION    FOR  45   TO   90   TRAVEL 


31  •  (IX  TWO,  |  Rivm  fO»  FA^TENM* 

TO    SEMAPHORE    SPECTACLE. 
(SEt    N«  10*0  AND  1041    ISSUl  Wl) 


Figs.  3344-335L     Filler  Block  to  Prevent  Travel  Figs.  3357-3360.     Filler  Block  to  Limit  Travel  of  Signal 

of  Signal  Arm.  Arms. 

Figs.    334i-336o.     Railway    Signal    Association    Standards. 


Figs.  336i-3395 


ACCESSORIES. 


469 


*<o 

^      o'      ^          _  z'd--  -    H 

i                                                                             . 

|r            •* 

RED 

WHITE 

RED 

L. 

<fi       I 

J  ffovndHead  Brass 

Screw.  /VoJ/  Wre 
\ 

WHITE 

3LACH 

WHITE 

Back. 

No.l- Absolute  Stop  Signal  Cannot  be  passed  /'n  sfof>  positron 
without  clearance  card,  cauf/on  card,  or  permission  to  pro- 
ceed in  ivritlng  by  order  of  the  superintendent. 


"S 

/?«? 

W///7F    j 

*% 

RED 

^ 

Front. 


1 

WHITE                                      \BLACK 

N 

WHITE 

y 

Back 

No.2~ Station  and  Train  Order  Absolute  Stop  Signal.    Maybe 
passed  in  stop  position  by  hand  signaf  giren  by  s/gnaf 
man  on  ground. 


RED 


Front. 


WHITE 


Back. 

No.  3-  Au  tomatic  B/ock  Permissive  S/gnaf.     May  be  passed  /n  aanger 
position  if  train  has  been  stopped  by  time  fab/e  ru/es. 

K....g.'— ^« -28'- f-  --<9-~  — -t"— S—-^ 


YELLOW 


Front 


\   ^       I 

WHITE 

X 

*(V|        | 

BLACK 

3T 

**>*      1 

WHITE 

_\ 

Back.                               "iTGuage  Brass-.      A" 

Edge  Vi'ew  of  all  Blades. 
Afa.-#-  Distant  Caution  S/gnaf.    /nd/cats're  of  s/gna/  fo  iv/tfch 
it  refers 

Figs.  3361-3369.     Semaphore  Blades.     New  York,  New 
Haven  &  Hartford. 


Figs.      3378-3385- 
Types  of  Semaphore 
Bearings     for     Iron 
Pipe     Post    Outside 
Connected  Signals. 


Figs.  3386-3395- 
Types    of    Sema- 
p  h  o  r  e   Bearings 
for  Wooden   Sig- 
nal Posts. 


Figs.  3370-3377.     Types  of  Three-Light  Semaphore  Castings. 


ACCESSORIES. 


igs-  3396-3403 


Figs.    3397-3398.      Types    of    Three-Light    Semaphore 
Castings. 


Figs.    3399-3400.      Two    Types    of    "Universal"     Semaphore 

Castings.     Four  Openings  for  Roundels  are  Provided, 

So  That  the  Lantern  May  be  Placed  Either  on 

Top  of  the  Post  or  on  One  Side. 


Fig.    3402.      R.     S.     A.     Standard 
Spectacle  Rings. 


Fig-  3396.     Standard  Clearance  Diagram  for  Semaphore 
Signals.      New    York   Central   &   Hudson    River. 


Fig.  3401.     Location   Plan  for  Automatic  Block  Signal       Fig.  3403.    go-Deg.  Main  Line  Semaphore  Casting,  made 
in  a  Cut  or  on  a  Fill.    Union  Pacific.  to  R.  S.  A.   Standard. 


Figs.  3404-3418 


ACCESSORIES. 


•  14" -j 


Figs.  3404-3408.     Types  of  One- 
Light  Semaphore   Castings. 


Figs.  3409-3415.     Types  of  Two-Light  Semaphore  Castings. 


k--7<?---»j 

-4- 


1X15  Bo /fs' 


6x8  Upr/ghfs  long 
enough  to  reach  so//d 
foundation 


n-  -   -  -   - 

--/ou  - 

[VAVV 

CIS 

H 

^-~ 

0 

Y 

s 

^\ 

i. 

§ 

1"!^ 

3 

1 

s 

^ 

J 

a 

Figs.    3416-3417.      Timber    Foundation    for    Automatic       Fig.   3418.     Layout  for  Automatic   Block   Signals   at  a 
Block   Signals.     Southern    Pacific-Union   Pacific.  Station.     Southern  Pacific-Union  Pacific. 


472 


ACCESSORIES. 


Figs.  3419-3427 


Sect/on  froucfft  Case 
Secf/onTop  of  Door 

Figs.  3419-3420.    Disk  Signal  Head  and  Details.    Hall  Signal  Company. 


Figs.  3423-3424.    Types  of  Two-Light  Semaphore  Castings. 


Figs.    3421-3422.      Mechanism    and    Batt  ry    Case    for 

Electro-Gas   or  Electric   Motor   Signal.     Hall 

Signal  Company. 


Figs.  3425-3427.     Parts   for  Converting  a   Sema- 
phore Casting  from  One  to  Two- 
Light. 


Figs.  3428-3435 


ACCESSORIES. 


473 


Fig.   3429.     Com- 
pensator Foun- 
Fig.  3428.     Crank  dation. 

Foundation. 


Fif'    343wr,TT"     Fig.  3431-    Dwarf 
Way   Wheel  J^JJ   Founda- 

Foundation.  .- 


Fig.  3432.   Straight    Fig.  3433.  Bracket 

SignalPole  SignalPole 

Foundation.  Foundation. 


ou/icfcrf/on 


\\ 


£>.C  four>cfaf/on    bottom. 


Fig-    3434-     Pipe   Carrier   Foundation. 
Figs.   3428-3434.     Railway   Signal  Asso- 
ciation   Standard   Foundations. 


Fig.  3435-     Double-Head  Disk  Signal  Mounted  on  Iron  Pipe 
Post.     Hall   Signal   Company. 


474 


ACCESSORIES. 


Figs.  3436-3443 


k 3'S---  -I 


Fig.   3436. 


Iron   Pipe    Bracket    Post. 
Reading. 


Philadelphia    & 


Fig-  3437-     Style  B   Motor  Signal   Operated  by  "Chlo- 
ride Accumulator"  on   the   Southern   Pacific. 
The  Union  Switch  &  Signal  Company. 


Figs.  3438-3439.     Standard  Upper  Left  Hand  Quadrant 

Semaphore  Signal.     New  York,  New  Ha.ven 

&  Hartford. 


Fig.    3440.      Cast    Iron    Foundation    for    Iron    Pipe 
Posts. 


Depth  to  be  from  3to5feet 
iyjo  Character 
of  Ground- 


Figs.   3441-3443.     Concrete   Automatic   Signal   Founda- 
tion.    Southern   Pacific-Union    Pacific. 


Figs.  3444-3452 


ACCESSORIES. 


475 


1 «**- > *•<• • 


:-ol- IT  L . 


!   Fig.  3448.     Standard  Clearance  for  Signals  Located 


Between   Tracks.     Sunset   Lines. 


1-— ff 


_/-^ J 


Figs.  3444-3446.    Suspended  Automatic  Block  Signal.     New 
York,  New  Haven  &  Hartford. 


3FC~r/O/*Gi-    WfW 


StCT/Off^i.    \"f*v  L//v£   #-£ 


Figs.  3449-3450.     R.  S.  A.  Standard  Pinnacles. 


Fig.    3447.      Electro-Pneumatic    Interlocking    Signals    on 

Bridges,      Delaware,    Lackawanna   &   Western.  Figs.  3451-3452.     Pipe  Guides  for  Iron  Pipe  Posts. 


476 


ACCESSORIES. 


-  3453-3464 


k- 


Arm 


•*H a  » 

<?*!  ^  ^.Core9//6 


J?_  _     /^" ~ „ '^ > 


r^    ' 

r  •  * 


r -"--_T 

k s'o -*)*- 


/o'o 


--p SB      -- 

One  Arm  Signa/— — "'^~          t  „ 

Three  Arm  £iyHa/*H**^ 
Fig-  3453-     Standard  Iron  Pipe  Signal  Post.     New  York  Central  &  Hudson  River. 


AT 


V 


XT 


I  I  I  I 

1 1 1 1 1 1 1  1 1 1 1 1 1 1 1 1 1 1 1 1 1  1 1  1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1  1 

Figs.  3454-3455.    Diagram  Showing  Method  of  Number-      Fi^s-   3456-3457-      Number   Plate   for   Automatic   Block 
ing   Automatic    Block    Signals.      Southern    Pacific-  Signals.     New  York  Central  &  Hudson 

Union  Pacific.  River. 


Figs.   3458-3459.     Number   Plate   for  Automatic    Block       Fig.    3460.      Cast    Iron    Number    P-^ate    for    Automatic 
Signals.     Southern  Pacific-Union  Pacific.  Block  Signals.    Chicago,  Milwaukee  &  St.  Paul. 


Figs.  3461-3462.     Semaphore  Blade  Clasps.     W.  F.  Bossert  Manu- 
facturing Company. 


Figs.     3463-3464.       Illuminated    Auto- 
matic Block  Signal  Marker. 
Pennsylvania   Railroad. 


Figs.  3465-3478 


ACCESSORIES. 


477 


Names      of      Parts      Mechanically 

Locked    Semaphore    Bearings; 

Figs.  3465-3468. 

1  Semaphore    Bearing 

2  Semaphore  Shaft 

3  Journal 

4  Pipe  Plug 

5  Shaft  for  Semaphore  Crank 

6  Semaphore    Crank    Shaft    Sepa- 

rator 
Segment 
Segment 
Pin  and  Cotters 
Pawl 

Semaphore  Crank 
Adjusting  Bolt 
Hand-hole  Plate 
Hand-hole  Plate  Clamp 
Handle 
Semaphore  Bearing 


22 


7 
8 
9 
10 
ii 
12 
13 
14 
15 
16 
17 
18 
19 

20 
21 
22 
23 
24 


Pin 

Female      Half     of     Semaphore 

Crank 
Bushing 

Ma/te  Ha/f  of  Semaphore  Crank 
Adjusting  Bolt 
Journal 
Semaphore  Shaft  Separator 


Figs.  3465-3466.     Mechanically  Locked  Semaphore  Bearing  for  6o-Deg. 
and  75-Deg.  Signals.    The  Union  Switch  &  Signal  Company. 


Figs.    3472-3476.      Types    of    Back 
Spectacles. 


Figs.  3467-3468.     Mechanically  Locked  Semaphore  Bearing  for 
9O-Deg.  Signals.     The  Union  Switch  &  Signal  Company. 


CffST 


Figs.    3469-3471.      Cast    Iron    Signal    Foundations    and  Figs.  3477-34/8.     Cast  Iron   Ladder   Foundation. 

Balance  Lever  Stands  Combined.  Railway  Signal  Association  Standard. 


Figs.  3465-3466  show  a  mechanically  locked  semaphore  bear- 
ing made  by  the  Union  Switch  &  Signal  Co.  The  object  of  this 
device  is  to  prevent  a  signal  from  being  cleared  by  any  other 
means  than  the  up  and  down  rod.  Figs.  3467-3468  are  used 
for  90°  signals.  The  up  and  down  rod  is  attached  to  one  end 
of  semaphore  crank  11,  which  has  a  jaw  at  its  other  end.  In 
this  jaw  rests  a  lug,  at  the  end  of  pawl  10.  10  is  pinned  to 
segment  8,  which  rests  against  a  lug  on  11.  8  engages  with  1 
to  clear  the  signal  wten  the  rod  is  raised.  If  any  attempt  Is 
made  to  clear  the  signal  by  moving  the  semaphore  casting  the 
lug  at  the  end  of  10  will  slip  out  of  the  jaw  and  10  will  en- 


gage  the  projection  of  the  bearing  casting,  thereby   preventing 
movement  of  the  semaphore  casting. 

Figs.  3465-3466  are  used  for  60°  and  75°  signals.  The  up 
and  down  rod  is  attached  to  crank  19,  which  turns  loosely  on 
the  semaphore  shaft.  Casting  21  is  rigidly  attached  to  the 
shaft.  It  carries  a  lug  which  projects  through  the  opening  in 
19.  Pawl  17  is  pinned  to  21  and  rests  normally  in  a  depression 
of  the  circumference  of  19.  Any  attempt  to  clear  the  signal 
from  the  semaphore  casting  will  cause  17  to  slide  out  of  Its 
seat  and  engage  in  the  notch  of  the  casting  16,  thereby  prevent- 
ing movement  of  the  semaphore  casting. 


478 


ACCESSORIES. 


Figs.  3479-3482 


ELECTRO-MECHANICAL  SLOTS 


The  electro-mechanical  slot,  when  separate  from  the  signal 
operating  mechanism,  is  placed  in  the  line  of  connection  to  me- 
chanically operated  signals  in  order  to  insure  that  a  signal  will 
indicate  stop  even  though  the  lever  to  which  it  is  connected 
may  not  have  been  restored  to  the  normal  position  after  the 
passage  of  a  train.  It  is  particularly  valuable  at  the  entrance 
to  the  first  block  in  a  series  of  controlled  manual  blocks  insur- 
ing the  restoration  of  the  initial  signal  to  the  stop  position 
and  Its  lever  to  normal  after  the  passage  of  a  train,  thus  pre- 
venting other  trains  following  on  the  same  clear  indication. 


UNION   ELECTRO-MECHANICAL   SLOT. 

The  electro-mechanical  slot  made  by  the  Union  Switch  & 
Signal  Co.  is  shown  in  Pigs.  3479-3485.  As  will  bo  seen  from 
Figs.  3481-3482  the  up  and  down  rod,  which  is  moved'  upward 
to  clear  the  signal,  is  carried  through  an  iron  box,  fixed  to  the 


Figs.  3479-3480.     Electro-Mechanical  Slot.     The  Union 
Switch  &  Signal  Company. 

signal  post  between  the  signal  arm  and  the  balance  lever. 
Referring  now  to  Pigs.  3483-3485,  the  frame  K  and  the  parts 
attached  to  it  move  up  and  down  with  the  rod.  The  electro- 
magnet M,  when  energized,  keeps  rods  TJ  and  E  rigidly  con- 
nected and  the  signalman  has  full  control  of  the  signal.  When 
the  magnet  is  de-energized  the  lifting  of  the  rod  U  does  not 
lift  E,  and  consequently  has  no  effect  on  the  signal  arm. 
Rod  TJ  is  connected  at  its  lower  end  to  the  balance  lever  and 
to  frame  K  at  J.  Frame  K  supports  the  magnet,  the  guide 


K',  spring  L  and  bolts  J  and  H.  The  lever  G  is  pivoted  so  as 
to  move  radially  on  H.  Spring  T  is  fixed  to  the  bottom  of  the 
case  and  presses  against  roller  I,  in  lever  G,  normally  holding 
the  latter  in  position  shown.  Roller  N,  in  lever  G,  rests  under 
pawl  F,  which  is  pivoted  in  rod  E  at  X. 

The  centers  H,  N  and  X,  are  normally  (when  signal  operat- 
ing lever  is  normal)  out  of  line.  Any  upward  pressure  applied 
at  H  consequently  tends  to  move  lever  G,  to  the  left  on  H,  as 
a  pivot.  This  causes  roller  N  to  move  from  beneath  the  pawl 
F,  which  is  not  movable  to  the  left,  as  a  result  of  the  resist- 
ance offered  by  the  weight  of  the  semaphore  casting  pressing 
downward  at  X  upon  pawl  F.  When  magnet  M  is  energized 
this  movement  sidewise  of  G  is  resisted  at  O,  its  upper  extrem- 
ity, as  the  link  P  pivoted  thereto  is  held  down  by  the  armature 
R.  Pivots  S,  Q  and  O  are  normally  out  of  line,  so  that  when 
M  is  de-energized  any  attempt  to  move  G  to  the  left  causes 
armature  R  to  move  upward,  the  pivot  S  being  fixed,  and 
consequently  permits  the  roller  N  to  move  from  under  pawl  P. 
But  if  the  magnet  M  is  energized  its  power  is  ample  to  hold  R 
down  ;  and  thus  to  prevent  the  movement  of  roller  N  from  be- 
neath pawl  F.  Consequently  any  upward  pressure  on  U  lifts 
the  frame  K  bodily  with  all  members  of  the  slot  engaged  as 
shown,  and  the  signal  is  thereby  cleared.  Spring  T,  being  se- 
cured to  the  case  ceases  to  press  against  lever  I  the  instant 
this  movement  begins,  and  hence  its  normal  tendency  to  force 
roller  N  under  pawl  P  is  not  present  when  the  signal  is  clear. 

The  upper  part  of  the  slot  is  so  designed  as  to  provide  an 
air  cushion  for  relieving  the  shock  that  would  otherwise  result 
when  the  signal  returned  automatically  to  the  stop  position. 
Roller  3  is  a  guide,  traveling  on  the  inside  of  the  cylinder, 
but  not  at  any  time  touching  the  surface  covered  by  the  pis- 
ton. When  a  signal  has  been  put  in  the  clear  position,  all  the 
movable  parts,  K.  M,  F,  etc.,  are  in  the  upper  part  of  the 


Figs.   3481-3482.      Electro-Mechanical    Slot  and    Rotary 

Circuit  Controller  Applied  to  a  Pipe  Post  Signal, 

Wire  Connected. 

case,  and  E,  D,  B,  C,  etc.,  are  at  the  upper  extremity  of  their 
stroke.  Point  I  is  free  from  spring  T.  Then,  when  a  train 
passes  and,  by  shunting  the  track  circuit,  de-energizes  M,  the 
armature  R  is  released  and  the  weight  of  the  semaphore  cast- 
ing, acting  through  the  several  members  described,  forces  the 
roller  N  from  under  F.  The  rod  E,  with  its  attachments  B,  C, 
D,  then  drops  by  gravity,  restoring  the  signal  to  the  stop 
position.  If  now  the  signalman  pulls  the  rod  U  down  again 
and  attempts  to  clear  the  signal  a  second  time  (before  M  has 


Figs.  3483-3487 


ACCESSORIES. 


479 


Names  of  Parts,  Electro-Mechanical  Slot; 
Figs.  3483-3485- 


Figs.  3483-3485.     Electro-Mechanical  Slot.     The  Union 
Switch  &  Signal  Company. 

been  re-energized)  he  can  push  up  II,  J,  N,  M,  etc.,  but  this 
movement  will  have  no  effect  on  F  and  E,  and  the  signal  will 
remain  in  the  stop  position.  When  the  train  goes  out  of  th« 


B  Buffer  Piston  N 

C  Buffer  Shield  O 

D  Buffer  Cylinder  P 

E  Connecting  Rod  Q 

F  "Pawl  R 

G  Swinging  Lever  S 

H  Bolt  T 

I  Bolt  U 

J  Bolt  V 

K  Slide  Plate  Frame  W 

K1  Guide  X 

L  Spring  Y 

M  Magnet 


Roller 

Pivot  Bolt 

Link 

Pivot  Screw 

Armature 

Pivot  Screw 

Spring 

Up  and  Down  Rod 

Jaw 

Bolt 

Pivot  Bolt 

Bolt 


block  section,  M   is   energized  and  the  signalman's   control  over 
E,  and  the  signal  is  restored. 


HALL    ELECTRO-MECHANICAL     SLOT. 

The  Hall  Signal  Company's  electro-mechanical  slot  for  sem- 
aphore signals,  shown  in  Figs.  3486-3487,  is  designed  to  be 
mounted  near  the  base  of  the  signal  post,  where  it  will  be 
easily  accessible.  All  movable  parts  can  be  plainly  seen  and 
easily  inspected  or  removed  without  dismembering  the  entire 
mechanism.  The  case  is  roomy  but  not  over  large,  and  the 
magnet  is  fixed.  The  details  and  construction  are  shown  !n 
Figs.  3486-3487.  In  Fig.  3486  A  represents  the  cast  iron 
case  ;  B  is  the  lower  operating  rod,  and  C  the  upper  operating 
rod,  carrying  the  dashpot  Q,  attached  in  the  usual  way.  D  is 
a  powerful  iron-clad  magnet  mounted  on  a  stand  which  la 
rigidly  fastened  to  the  case ;  E  is  the  armature  secured  loosely 
to  the  lever  F  by  the  threaded  pin  G.  G  is  slightly  smaller  than 
the  hole  in  F,  through  which  it  passes,  and  has  a  semi- 
spherical  head,  after  the  manner  of  a  ball  and  socket  joint. 
This  is  to  allow  E  to  make  good  contact  with  D,  despite  any 
small  lack  of  adjustment  in  F.  Lever  F  is  pivoted1  at  O.  H  Is 
a  phosphor  bronze  spring  used  to  restore  lever  F  to  its  normal 


Fig.  3486.    Single  Electro-Mechanical  Slot. 
Company. 


Hall  Signal      Fig.    3487. 


Double    Electro-Mechanical 
Signal    Company. 


Slot.       Hall 


480 


ACCESSORIES. 


Figs.  3488-3492 


position,  but  exerts  no  appreciable  pressure  otherwise.  I  is  a 
cast-iron  sleeve  riveted  to  the  lower  rod  B,  and  carries  the 
latch  J,  pivoted  to  the  lug  K,  which  is  part  of  the  sleeve  I  ;  J 
carries  a  roller  L,  to  reduce  friction  when  traveling  against 
lever  F.  The  lower  end  of  C  extends  within  B,  and  carries  a 
pin  M,  working  in  slot  N,  cut  in  B.  This  is  to  allow  the  signal 
to  be  pulled  to  the  stop  position,  as  M  projects  beyond  the 
edge  of  B,  on  both  sides.  Both  rods  are  notched  at  P,  to 
allow  the  projection  of  latch  J  to  engage  with  upper  rod  C. 
When  the  magnet  D  is  energized  the  signal  can  be  cleared.  The 
magnet  holds  F  against  latch  J  by  pressing  against  roller  L, 
and  then  if  B  is  raised  C  must  also  go  up,  for  latch  J  will 
engage  with  lower  end  of  C.  If,  while  the  signal  is  in  the 
clear  position,  magnet  D  becomes  de-energized  the  weight  of 
the  semaphore  casting  acting  against  lever  F,  through  C  and 
latch  J,  will  force  F  away  from  D ;  and  J,  in  tripping,  will 
allow  C  to  pass  by,  and  the  signal  will  assume  the  stop  position. 
When  F  Is  forced  away  from  D  it  compresses  spring  H,  which 
remains  compressed  until  B  has  been  restored  to  its  normal 
position,  allowing  J  again  to  enter  the  notch  P ;  when  this 
occurs  H  restores  F  to  contact  with  D.  If  it  is  attempted  to 


Up&Down 
Rod 


Fig.  3488.     Application  of  Electro-Mechanical  Spindle 
Slot.     General  Railway  Signal  Company. 


clear  the  signal   when  D  is  de-energized,   F   will   be   forced  back 
in  the  same  manner  as  above  described. 

The  double  slot,  shown  in  Fig.  3487,  is  used  whore  two  arms 
of  a  signal  are  slotted,  and  is  much  more  compact  and  con- 
venient than  two  single  slots.  This  slot  consists  essentially  of 
the  mechanism  of  two  single  slots  mounted  side  by  side  in  one 
case,  and  it  operates  exactly  as  above  described. 


is  a  circular  disk  provided  with  a  square  ho'.e  Figs.  3490-3492,  In 
the  center  for  attaching  to  the  spindle.  On  the  disk  is  mounted 
the  mechanism.  This  consists  of  a  frame  supporting  the  mag- 
nets and  a  dog  in  the  form  of  the  segment  of  a  circle  and  a 
projection.  The  projection  rests  normally  in  a  notch  In  th« 


001=6 


Fig.    3489.      Semaphore    Shaft    Used    with    Electro-Me- 
chanical   Spindle    Slot. 


circumference  of  the  case,  Figs.  3490-3492.  In  the  upper  part 
of  the  frame  is  pivoted  a  lever,  whose  arms  are  at  right  angles 
The  short  arm  rests  normally  against  the  upper  face  of  th* 


Fig.    3490.      Normal    Condition    of    Electro-Mechanical 
Spindle  Slot.     General  Railway  Signal  Company. 


dog.  The  long  arm  carries  a  roller  working  in  a  jaw  keyed 
to  the  pin  which  carries  the  armature  arm.  This  pin  is  sup 
ported  by  a  projection  on  the  disk.  When  the  magnet  is  en 
ergized  the  armature  acting  through  its  arm  and  the  jaw  and 
lever  holds  the  dog  in  the  notch,  and  the  signal  can  be  cleared. 


Fig-  3491-     Electro-Mechanical  Spindle  Slot  Energized 
and   Signal  Clear. 


Fig.  3492-    Electro-Mechanical  Spindle  Slot  Disengaged. 
Signal   About   to  Assume  the   Stop   Position. 


G.    R.    S.    SPINDLE    SLOT. 

The  spindle  slot  mode  by  the  General  Railway  Signal  Com- 
pany Is  designed  to  be  placed  on  -the  spindle  of  a  signal  as 
shown  in  Figs.  3488-3492.  It  consists  of  a  circular  iron  case 
provided  with  a  lug,  Figs.  3490-3492,  to  which  the  up  and  down 
r«d  la  attached.  This  case  turns  loosely  on  the  spindle.  Inside 


Fig.  3491.  When  the  magnet  is  de-energized  the  counterweight 
of  the  signal  forces  the  dog  out  of  the  notch  and  trips  the 
armature,  as  shown  in  Fig.  3492.  All  shock  is  absorbed  by  a 
dash  pot  mounted  on  a  bracket  above  the  arm  casting  so  ar- 
ranged that  the  casting  will  strike  against  the  piston  rod,  as 
shown  in  Fig.  3488. 


Figs.  3493-3494 


ACCESSORIES. 


481 


SWITCH  MACHINES  AND  SWITCH  STANDS 


h    Machine.      W.    F. 


Manufacturing  Company. 


TRIPLELOCK    SWITCH    MACHINE. 

The  W.  F.  Bossert  Mfg.  Co.  manufactures  a  switch  machine 
arranged  to  interlock  a  signal.  It  has  an  operating  lever  par- 
allel to  the  track  which  unlocks  the  point,  throws  the  switch 


cleared  until  the  switch  lever  has  been  returned  to  its  normal 
position  and  switch  points  locked.  The  machine  will  not  oper- 
ate unless  the  movement  of  the  switch  points  corresponds  with 
the  movement  of  the  operating  lever. 


Fig.  3494.     Triplelock  Switch  Machine  Open,  Showing  Wheel  and  Derail  Movement  of  Lock. 


and  re-locks  the  points  in  both  positions  with  the  facing-point 
lock. 

The  lever  lock  between  the  switch  and  the  signal  lever  is  so 
arranged  that  the  signal  lever  must  be  in  the  full  lock  position 
before  the  switch  lever  can  be  moved,  and  after  the  switch  lever 
movement  has  been  started  the  signal  lever  cannot  again  be 


A  dust  and  waterproof  circuit  controller,  attached  to  the  sig- 
nal lever,  takes  the  place  of  a  switch  controller  operated  by  the 
movement  of  the  switch  points. 

The  switch  points  and  the  derail  are  thrown  at  the  same 
time,  both  being  operated  direct  from  the  operating  lever  and 
independent  of  ench  other  outside  of  the  switch  stand.  The 


482 


ACCESSORIES. 


Figs.  3495-3499 


derail  connection  in  the  switch  stand  has  seven  inches  positive 
movement. 

It  can  be  applied  to  a  right-hand  or  a  left-hand  switch,  or 
can  be  installed  to  operate  movable  point  frogs.  The  signal 
lever  attachment  will  operate  either  a  mechanical  or  power 
signal.  This  switch  machine  is  also  furnished  with  an  electric 
approach  lock,  which  can  be  controlled  from  any  distant  point, 
or  used  in  connection  with  approach  locking.  All  machines 
have  an  automatic  manual  control  lock,  making  it  impossible 
to  insert  padlock  unless  the  lever  arms  are  in  a  normal  position. 


Figs.  3495-3497.    Double  Ground  Lever  Interlocking  Stand,  with  Disk  Locking. 
The  Union  Switch  &  Signal  Company. 


1  Base 

2  Cap 

3  Dog 

4  Dog 


Names  of  Parts,  Triple  Ground  Lever  Interlocking  Stand;  Figs.  3498-3499. 


5  Dog 

6  Rack 

7  Lever 

8  Pinion 


9  Shaft 

10  Chain 

11  Bolt 

12  Bolt 


13  Bolt 

14  Set  Screw 

15  Locking  Pin 
17  Rivet 


10 


Figs.  3498-3499.     Triple  Ground  Lever  Interlocking  Stand.     The  Union  Switch  &  Signal  Company. 


Figs.  3500-3514 


ACCESSORIES. 


483 


Figs.  3500-3508.     Double  Ground  Lever  Interlocking  Stand.     The  Union 
Switch  &  Signal  Company. 


Figs.  3509-3510.    Rim  Lock  Ground  Lever  Interlocking  Stand. 
The   Union    Switch    &   Signal   Company. 


m 


Fig.  3512. 
Torpedo. 


Figs.   3513-3514.     Torpedo  Placer.     The  Union   Switch 
&  Signal  Company. 


484 


ACCESSORIES. 


3515-3524 


TESTING  INSTRUMENTS 


Fig.   3515.      Portable    Recording   Ammeter. 


Fig-   35i6.     Recording   Voltmeter   and   Resistance   Box 
Showing   Connections. 


vww 


Fig.  3517.  Recording  Volt-      Fig.  3518.  Recording  Volt- 
meter,  Front   View.  meter,  Rear  View, 

Figs.  3515-3520.     Recording  Instruments.     Bristol 
Company. 


Fig.        3519.        Recording  Fig.   3S2O      Circuit   Dia_ 

Pressure    Gage,    Rear  gram  Recording  Ammeter 

View,  Cover  Re-  with  Current  Transformer 

moved-  for  Alternating  Current. 


Fig.  3521.     Circuit  Diagram    Recording  Voltmeter  with 
Potential  Transformer  for  Alternating 

Fig.  3522.     Recording  Pressure  Gage  in  Case.     Bristol 
Company. 


Fig.  3523-     Section  of  Recording  Ammeter  Chart. 


Fig.   3524.     Section   of   Recording   Voltmeter  Chart. 


Figs.  3525-3534 


ACCESSORIES. 


485 


Fig.  3527.     Edgewise  Switch- 
Fig-  3525.     Switchboard  Ammeter.  Fig.  3526.     Switchboard  Voltmeter.  board  Voltmeter. 
Figs.   3525-3527.     Electrical    Measuring   Instruments.     Weston  Electrical  Instrument  Company. 


Fig.  3528.     Switchboard  In- 
strument.    Ammeter  or 
Voltmeter.    General 
Electric  Company. 


Fig.     3529.       Synchronism 
Indicator.     General 
Electric  Com- 
pany. 


Fig.  353O-     Portable  Direct  Current  Voltmeter. 


Fig.  3531.      Portable    Alternating    Current    Voltmeter. 


Fig.  3532.     Portable  Alloy  Shunts. 


Fig.    3533-     Portable     Direct     Current     Volt-Ammeter. 

Figs.  3530-3534.     Electrical  Measuring  Instruments. 


Fig.  3534.    Portable  Milli-Ammeter. 
Weston  Electrical  Instrument  Company. 


486 


ACCESSORIES. 


Figs.  3535-3539 


GENERAL  ELECTRIC  DIRECT  CURRENT   INSTRUMENTS. 

For  general  testing  on  direct  current,  an  instrument  of  the 
permanent-magnet  D'Arsonval  type  is  to  be  preferred.  These 
instruments  show  polarity,  and  have  very  low  internal  losses, 
as  the  permanent  magnet  furnishes  a  good  part  of  the  energy 
necessary  to  operate  the  instrument.  The  moving  elements  of 
this  type  of  instrument  are  very  light  and  the  indications 
quite  "dead  beat"  or  well  damped.  The  damping  feature  is 
obtained  by  the  Foucault  currents  generated  In  the  aluminum 
frame  on  which  the  wire  for  the  moving  coil  is  mounted. 
This  frame  moves  across  the  field  of  the  permanent  magnet 
and  the  currents  generated  in  it  furnish  a  very  good  damping 


Fig.  3535- 

Portable  Instrument. 
MilH-volt-ammeter. 


Fig.  3536.     Testing  Instrument. 

Cover  Removed.    Voltmeter, 

Wattmeter  or  Ammeter. 


Fig.   3537- 
Portable   Shunt  for 
Milli-volt-ammeter. 


effect.  On  account  of  the  fact  that  an  ammeter  and  voltmeter 
of  this  type  have  practically  the  same  structure,  It  is  possible 
to  make  a  very  satisfactory  combined  ammeter  and  voltmeter 
from  a  single  instrument,  that  is,  the  instrument  Itself  is  a 
milli-voltmeter  and  for  measuring  current,  the  milll-voltmeter 
measures  the  drop  across  a  shunt,  this  drop  of  course  being 
proportional  to  the  current  flowing  in  the  shunt.  For  meas- 
uring voltage,  it  is  only  necessary  to  connect  in  series  with  the 
milli-voltmeter  a  series  resistance  of  whatever  amount  is  re- 
quired for  the  voltage  under  measurement.  (Figs.  3562-3.) 

GENERAL    ELECTRIC  ALTERNATING  CURRENT   INSTRUMENTS. 

Alternating-  current  instruments  have  considerably  higher 
internal  losses  as  it  is  necessary  to  furnish  all  of  the  en- 
ergy to  operate  them.  The  most  satisfactory  instruments  for 
alternating  current  voltmeters  and  wattmeters  are  known 
as  the  dynamometer  type,  that  is,  the  construction  consists  of 
a  set  of  stationary  coils  and  a  moving  coil  and  the  armature. 
This  type  of  Instrument  is  very  accurate  on  alternating  cur- 
rent and  can  also  be  used  on  direct  current  although  it  is  not 
as  accurate  as  the  D'Arsouval  type  for  direct  current  work. 
On  account  of  the  high  resistance  of  the  windings,  the 
dynamometer  type  of  instrument  cannot  very  well  be  used 
as  a  combined  ammeter  and  voltmeter.  For  alternating 
current  ammeters,  the  most  satisfactory  type  is  the  iron  vane 
instrument  where  the  current  passes  through  a  stationary  coil 
and  exerts  a  turning  influence  on  a  vane  placed  on  the  shaft. 
(See  Fig.  3561.) 

One  other  type  of  alternating-current  instrument,  which  is 
probably  better  for  low  voltage  signal  testing  than  the  dyna- 
mometer type  of  instrument,  is  the  hot  wire  instrument.  This 
type  instrument  has  a  very  fine  silver  platinum  wire,  through 
which  the  current  to  be  measured,  or  a  shunted  portion  of  it,  is 
passed.  The  current  heats  the  wire  and  a  spring  takes  up  the 
expansion,  and,  through  a  small  pulley  and  a  flexible  connection, 
a  turning  moment  is  given  the  shaft,  resulting  in  an  indication 
proportional  to  the  current  passing  through  the  platinum  wire. 
This  instrument  can  be  made  for  a  full  scale  current  of  about 
Vt,  ampere  and  low-range  voltmeters  down  to  five  volts  can 
b«  made  for  this  full-scale  current.  With  the  dynamometer 


type  of  instrument,  it  is  not  possible  to  make  a  satisfactory 
instrument  of  this  voltage,  which  has  a  full-scale  current  less 
than  about  one  ampere.  Unlike  the  D'Arsonval  type  which 
takes  a  current  proportional  to  the  reading  on  the  scale, 
alternating  current  instruments  take  a  current  proportional  to 
the  square  of  the  current.  That  is,  the  current  necessary  for 
one-half  scale  deflection  is  one-quarter  of  the  amount  necessary 
for  full  scale  deflection.  It  is  possible,  with  the  hut  wire  in- 
strument, to  furnish  a  combined  ammeter  and  voltmeter  by  fur- 
nishing series  resistance  for  different  voltages  and  external 
shunts  for  different  current  capacities.  (Fig.  3563.)  These  in- 
struments can  also  be  used  on  direct  current,  although  they  do 
not  show  polarity  and  have  much  higher  losses  than  the 
D'Arsonval  type.  These  losses  are  about  in  proportion  to 
10  :1  ;  that  is,  the  hot  wire  taking  0.25  ampere  for  full-scale 
deflection  and  the  D'Arsonval  taking  .025  ampere  for  full-scale 
deflections. 

GENERAL  ELECTRIC  ELECTROSTATIC  GROUND  DETECTORS. 

The  electrostatic  ground  detector  is  practically  an  electro- 
static voltmeter  operating  on  the  same  principle  as  the  quad- 
rant electrometer,  that  is,  it  is  based  on  the  electrostatic 
attraction  and  repulsion  of  a  set  of  stationary  and  moving 
vanes.  The  ground  detector  is  used  to  indicate  grounds  on  a 
single  or  polyphase  a.  c.  circuit.  This  instrument,  however, 
cannot  be  relied  upon  absolutely,  in  that  a  zero  indication 
may  not  necessarily  mean  that  the  line  is  perfectly  insulated. 
This  is  owing  to  the  fact  the  instrument  can  be  considered 
as  a  differential  voltmeter  measuring  the  difference  in  insulation 
resistance  between  the  two  sides  of  the  line  and  the  ground. 
If  both  sides  are  perfectly  insulated,  it  will  show  zero.  If 
both  sides  have  a  partial  ground  of  equal  resistance,  it  will 
still  show  zero  indication.  If  one  side  of  the  line  should  be  of 
lower  insulation  resistance  than  the  other,  the  indication  would 
show  on  the  low  side.  In  case  of  a  ground  on  one  side,  the 
instrument  will  immediately  indicate  full  voltage,  the  needle 
pointing  toward  the  line  or  the  phase  which  is  grounded. 


Fig.    3538.     Testing    Instrument. 


Fig.     3539.       Direct-Reading  '  Ohmmeter.       Queen     & 
Company. 


Figs.  3540-3544 


ACCESSORIES. 


487 


QUEEN    DIRECT    READING    OHMSIETER. 

This  instrument  is  arranged  to  measure  unknown  resistances 
directly  upon  a  calibrated  scale  without  calculation  or  refer- 
ence to  a  table  of  values.  The  principle  is  that  of  the  slide 
wire,  but  by  means  of  multipliers  of  1,  10,  100,  1,000  and 
10,000  the  range  and  accuracy  of  this  instrument  is  greater 
than  that  of  a  slide  wire  bridge  of  the  ordinary  type.  To  use 
the  instrument  it  is  only  necessary  to  place  the  unknown  re- 
sistance in  the  binding  post  mnrked  "line"  and  rotate  the  index 
until  a  balance  is  obtained.  The  unknown  resistance  is  then 
read  directly  from  the  scale.  If  the  multiplier  is  not  on  "1," 
the  scale  reading  must  be  multiplied  by  the  proper  factor.  A 
high-grade  pivot  and  jewel  D'Arsonval  galvanometer  forms  a 
part  of  the  instrument.  The  keys  "BA"  and  "GA"  are  for 
closing  the  battery  and  galvanometer  circuits,  respectively.  The 


/ 

s>    <s> 

© 

© 

\ 

\ 

i 

© 

e 

© 

/ 

Fig.    354O.     Direct    Reading    Ohmmeter.      Queen    &    Com- 
pany. 

switch  "BA"  must  be  placed  at  "in"  when  using  the  contained 
battery,  but  if  the  internal  battery  is  exhausted,  an  external 
battery  of  two  ordinary  dry  cells  can  be  connected  to  the  post 
"BA"  and  used  by  placing  the  switch  at  "out."  The  small 
lever  "L"  is  used  to  control  the  galvanometer  at  zero. 
The  instrument  is  balanced  by  determining  when  the  galva- 


Actual  Diagram 


Theoretical 
Fig.  3541.     Diagrams  of  Circuits  of  Fig.  3556. 

nometer  does  not  deflect  upon  balancing  the  circuits.  It  is  not 
essential  that  the  galvanometer  needle  stand  exactly  at  zero 
on  the  scale.  Due  to  some  amount  of  "shift"  in  the  galva- 
nometer, the  lever  "L"  is  used  to  return  the  needle  to  zero. 


UNIVERSAL  DUPLEX  TESTING  INSTRUMENT. 

Fig.  3568  shows  the  Universal  Duplex  testing  instrument  made 
by  the  Bryant  Zinc  Co.  The  case  is  fitted  with  a  lock 
and  strap  handle.  There  are  two  separate  deadbeat  D'Arsonval 
movements,  which  are  fitted  with  jewel  bearings.  The  volt- 
meter has  six  scale  values  and  the  ammeter  has  five  scale 
values.  There  are  but  two  binding  posts  used  for  each  meter. 
The  unique  feature  of  the  instrument  is  the  arrangement  of 
plugs,  by  means  of  which  any  scale  on  either  meter  can  be 
used  without  moving  any  wires.  The  length  of  each  scale  is 
three  inches.  They  are  divided  into  30  divisions,  which  are 
one-tenth  of  an  inch  apart,  for  quick  reading,  where  the  cur- 
rent and  voltage  are  continually  changing  when  testing  the 


Fig.  3542.     Universal  Duplex  Testing  Instrument. 

operating  current,  as  of  a  signal.  With  the  one-tenth  inch 
divisions  it  is  easy  to  follow  the  different  values  of  current 
and  voltage  while  the  signal  is  making  a  clearing  movement. 

There  are  both  voltage  and  current  scales,  designed  for  the 
rapid  and  accurate  testing  of  track  circuits,  relays,  indicators, 
slots  and  power  interlocking. 

To  determine  the  clearing  and  holding  current  of  a  signal 
with  this  instrument,  the  operation  is  as  follows : 

Insert  one  plug  in  the  30-rnilli-ampere  block  and  one  plug 
in  the  three-ampere  block.  When  the  circuit  is  closed,  the 


Figs.   3543-3544-     Counter  for   Signals. 
Manufacturing  Company. 


Veeder 


meter  will  indicate  amperes  on  the  three-ampere  scale.  When 
the  signal  is  in  the  clear  position,  the  needle  drops  back  to 
very  nearly  zero.  If  now  the  plug  in  the  three-ampere  block 
is  removed,  the  instrument  will  indicate  in  milli-amperes  the 
amount  flowing  through  the  slot  coils.  This  test  is  made  with- 
out disturbing  slot  wires  on  signal  or  wires  on  instrument. 

The  two  ammeter  posts  are  connected  directly  to  the 
galvanometer  movement.  This  makes  it  possible  to  use  addi- 
tional shunts  reading  0  to  30,  90,  120  amperes,  etc.,  if  de- 
sired. In  using  external  shunts,  it  is  only  necessary  to  remove 
the  ammeter  plugs  and  connect  shunt  to  the  two  posts. 


488 


ACCESSORIES. 


Figs.   3545-3551 


POTENTIAMETER    RHEOSTAT. 

Fig.  3571  shows  the  Potentiameter  rheostat  made  by  the 
Bryant  Zinc  Co. 

This  instrument  is  used  for  testing  the  operating  and  re- 
leasing current  of  relays,  locks,  slots,  indicators,  etc.,  which 
devices  in  many  cases  operate  on  very  small  amounts  of  cur- 


rent. In  a  range  of  resistance  from  2  to  2,000  ohms,  this 
instrument  will  allow  regulation  to  be  made  to  In  fractions  of  a 
milli-ampere. 

T  he  double-pole,  double-throw  switch  will  allow  tests  to  be 
made  in  connection  with  polarized  circuits  and  to  determine  the 
value  or  amounts  of  residual  magnetism. 


Fig.  3545-     Potentiameter  Rheostat.     Bryant  Zinc  Company. 


Fig.    3546.      Telegraph    Key. 

Figs.  3546-35^ 


Fig.  3547-     Telegraph  Sounder.  Fig.   3548.     Telegraph   Relay. 

Telegraph  Instruments.     Western  Electric  Company.      \ 


Figs.    3549-3550.     Magneto    Testing    Set   with   Telephone. 


Fig.  3551.    Telephone  Wall  Set. 
Western   Electric   Company. 


Figs.  3552-3562 


ACCESSORIES. 


489 


Fig.    3552.      Multipliers    for    Portable    Volt 

meters.     Weston  Electrical  Instrument 

Company. 


e 


:LH 


.e 


Fig.    3553-      Pocket   Track 
Circuit  Tester. 


Fig.  3556.     Pocket  Volt-Am- 
meter.    Bryant   Zinc 
Company. 


Fig.  3555.     Exploring  Coil   for  Alternating  Current 
Track    Circuit. 


Fig.  3554-     Adjustable  Re- 
sistance Testing  Box. 


Fig.  3557.    Portable  d'Arsonval 

Type   Voltmeter.     Louis 

M.  Pignolet. 


Fig-  3558.    A.  C.  and  D.  C.  Voltmeter. 
Louis  M.  Pignolet. 


TOOLS  AND  APPLIANCES 


Fig.  3559-     Tommy  Bar. 


, 

. 

•p.  .,„  7  

_^_r        ^s 

-%V                     4<t>                            f     M 

"^     "illf7 

^U  ^  ? 

^ 

-f"  .1  , 

^                             J  g* 

Jr.       fO) 

~^£i  

*  *±v 

ni*4r 

1              *                 L3 

/i/>    \^-/ 
fy'nt 

1r 

i 

Figs.   3560-3561.     Lock   Rod   Center   Punch.         Fig.  3562.    Special  Screw  Driver  for  Building  Posts,  Etc. 


4QO 


ACCESSORIES. 


Figs.    3563-3577 


Fig.  3563.     Glass  Hold-Down  for  Separators. 
"Chloride  Accumulator." 


TRACK   CIRCUIT   TESTER. 

This  instrument  was  designed  for  the  use  of  signalmen  in 
testing  for  track  circuit  troubles.  It  comprises  an  iron-clad 
electromagnet  wound  to  four-ohms  resistance,  with  an  easy 
working  armature,  all  of  which  are  covered  by  a  brass  shield, 
with  substantial  binding  posts,  flexible  wires  and  metal 
terminals.  The  instrument  is  shown  in  Fig.  3576. 


Fig.  3564.  Type  "E"  Fig.  3565.  Type  "E" 
Wood  Separator,  for  Wood  Separator  for 
"Chloride  Accumulator."  "Tudor  Accumulator." 


* 


Figs.   3570-3572.     Bolt   Connectors. 
"Chloride  Accumulator." 


Fig.   3567-     Type 

"B"  Hydrom- 

eter. 


Fig.  3568.     Type  "E" 
Hydrometer. 

Figs.  3567-3568.    Storage  Bat- 
tery   Hydrometers.      Elec- 
tric Storage  Battery  Com- 
pany. 


Fig  3566. 

Battery 

Hydrometer. 


Fig.    3569.      Hydrometer    Syringe 

(Specific  Gravity  Tester,  for 

Portable  Cells). 


Figs.    3574-3575-      Battery    Clean 
ing  Brush   and  Knife. 


3576.     Track  Circuit  Tester. 
Bryant  Zinc  Company. 


Fig.    3573-        Sol 

derail".  Pocket 

Torch. 


Fig.     3577-       Battery    Syringe. 


Figs.  3578-3582 


ACCESSORIES 


491 


MOTOR  CARS 


Fig.  35/8.     No.  28  Gasoline  Motor  Car  (All  Steel).     Fairbanks,  Morse  &  Co. 


FAIRBANKS    MORSE    MOTOR    CARS. 

The  No.  28  motor  car  made  by  Fairbanks,  Morse  &  Co. 
has  a  pressed  steel  frame  and  a  two-cycle,  two-cylinder,  air- 
cooled  engine,  one  cylinder  being  direct  connected  to  the  front 
axle  on  each  side.  The  cylinders  are  B1/^  in.  by  4  in.,  and  the 
cranks  are  entirely  enclosed.  The  engine  is  lubricated  by  oil 
mixed  with  the  gasoline,  which  passes  through  the  carburetor. 
The  car  weighs  400  Ibs.,  seats  three  persons,  and  will  develop 
speeds  up  to  30  miles  an  hour. 

The  No.  28  car  made  by  Fairbanks,  Morse  &  Co.  has  a  two- 
cylinder,  two-cycle,  air-cooled  engine  back  geared  2  to  1  to  the 
front  wheel,  developing  2%  h.  p.  The  cylinders  are  three 
inches  in  diameter.  The  car  has  spark  and  throttle  control  and 
an  automobile  float  feed  carburetor.  The  car  weighs  320  Ibs.  and 
operates  safely  at  speeds  up  to  20  miles  an  hour. 


Fig-   3579-      Showing   Motor  Car   Engine   and   Driving 
Gear  of  No.  30  Car.     Fairbanks,  Morse  &  Co. 


Fig-  358o.     Showing  Timer  Side  of  No.  28  Car. 
Fairbanks,  Morse  &  Co. 


Fig.   3581. 


Showing   the    Crank   Case   of   No.   28   Car. 
Fairbanks,   Morse   &  Co. 


Fig.  3582.     No.  30  Gasoline  Motor  Car  (All  Steel).     Fairbanks,  Morse  &  Co. 


492 


ACCESSORIES. 


Figs.  3583-3585 


Fig.  .3583.     2]  Gasoline   Motor  Car.     Fairbanks,   Morse   &  Co. 


Motor  Car  No.  30  made  by  Fairbanks,  Morse  &  Co.  has  a  steel 
tubing  frame  and  a  two-cylinder,  two-cycle,  three-part,  air- 
cooled  engine  with  2%  in.  by  3  in.  cylinders,  geared  direct  to 
the  driving  axle.  The  engine  has  the  automatic  lubrication 
provided  on  Car  No.  28.  The  car  will  seat  one  or  two  persons, 
runs  at  speeds  up  to  25  miles  an  hour  and  weighs  320  Ibs. 


ADAMS    MOTOR    CAR. 

The  Adams  Motor  Car,  made  by  Burton  W.  Mudge  &  Co.,  is 
of  the  direct  connected  four-wheel  type.  The  frame  is  built 
of  six  white  ash  rails  bolted  together  and  braced  and  re- 
inforced at  joints  and  wearing  points.  The  engine  is  a  4%  h.  p. 
two-cycle,  two-port,  air-cooled  single  cylinder  motor,  direct  con- 


nected to  the  rear  wheel  and  having  three  moving  parts,  the 
piston,  connecting  rod  and  crank  shaft  all  enclosed.  The  igni- 
tion is  jump  spark,  the  battery,  spark  coil  and  switch  being 
enclosed  in  a  locked  box  built  into  the  frame  of  the  car.  The 
oiling  is  accomplished  by  mixing  the  lubricating  oil  with  the 
gasoline.  Special  provision  is  made  by  a  grease  cup  on  the 
crank  case  for  lubricating  the  main  bearings,  and  the  crank  pin 
boarings.  The  car  can  be  used  with  three  or  four  wheels, 
but  the  four-wheel  type  is  standard.  The  body  wheels  are  17 
in.  in  diameter,  and  the  guide  wheels  14  in.  The  equipment 
includes  one  socket  wrench  for  the  engine,  one  combination 
wrench  and  a  book  of  instructions.  Figs.  3584-3585  show  the 
Adams  Motor  Car. 


Fig.  3584.     Adams  Motor  Car.      Rear  Wheel  Cut  Away  to  Show  Engine  and  Tool  Tray. 

Burton    W.   Mudge   &  Company. 


Fig.  3585.     Adams  Motor  Car.     Burton  W.   Mudge  &  Company. 


Figs.  3586-3591 


ACCESSORIES, 


493 


Fig-  3587.    Velocipede  Motor  Car  Fitted  with  Belle  Isle 
Engine.     Concrete  Form  &  Engine  Company. 


Fig.  3586.    Adams  Motor  Car. 


BUDA    MOTOR    VELOCIPEDES. 

Motor  velocipede  cars  are  made  by  The  Buda  Co.  in  both  three 
and  four-wheel  styles,  and  designed  to  carry  from  one  to  three 
persons.  The  two  lower  sills  of  the  frame  which  carries  the 


Fig-  35* 


Belle  Isle  Gasoline  Engine. 
&  Engine  Company. 


Concrete  Form 


Fig.  3589.     No.  I2A  Four-Wheel  Motor  Velocipede.    The  Buda  Company. 


Fig  3590     Four-Wheel  Motor  Velocipede.    The  Buda  Fig.    3591.      Three- Wheel    Motor    Velocipede.     The 

Company.  Buda  Company. 


494 


ACCESSORIES. 


Figs.  3592-3593 


engine  are  of  square  steel  tubing,  the  upper  sills  are  of  wood, 
and  the  guide  arm  is  also  of  wood  re-enforced  by  riveted  iron 
straps.  The  diagonal  brace  connecting  the  guide  arm  and  the 
frame  is  of  channel  iron.  The  brace  is  swiveled  at  the  guiding 
wheel. 

The  engine  is  of  the  four-cycle  type,  air  cooled.  Six  types  of 
these  cars  are  equipped  with  2 '4  h.  p.  engines,  and  one  type 
of  four-wheel  car  for  three  persons  with  4  h.  p.  The  cylinder 
is  bored  from  a  solid  bar  of  steel.  The  exhaust  valve  is  made 
of  pure  nickel,  and  the  crank  shaft  is  enclosed  in  an  aluminum 


ings.  The  main  wheels  are  17  in.  and  the  guide  wheels  14  In. 
in  diameter.  The  speed  can  be  regulated  from  three  to  30 
miles  an  hour.  All  types  of  cars  may  be  fitted  with  a  tray  for 
carrying  batteries  or  lamps. 


ROCKFORD    INSPECTION    MOTOR    CARS. 

The  Rockford  inspection  motor  cars  made  by  the  Chicago 
Pneumatic  Tool  Co.  are  four-wheel  cars  and  will  carry  from 
one  to  three  persons.  The  car  frames  are  of  welded  steel  chan- 
nels and  angles.  A  two-cylinder,  four-cycle,  air-cooled  engine 


Fig-  3592.     No.  4  Rockford  Section  Motor  Car.     Chicago  Pneumatic  Tool  Company. 


ig-  3593-     No.  2  Rockford  Signal  and  Lineman's  Car.     Chicago  Pneumatic  Tool  Company. 


casing.  The  engine  Is  lubricated  by  the  splash  system.  The 
equipment  of  the  car  Includes  a  waterproof  spark  coll  and  a 
duplicate  set  of  batteries.  The  gasoline  tank  holds  a  supply  for 
about  200  miles. 

The  Buda  cars  are  driven  through  the  front  wheel  by  a 
sprocket  wheel  attached  to  it  by  a  friction  arrangement  to 
prevent  breaking  the  chain  or  damaging  the  engine  in  case  of  a 
too  sudden  start  or  a  derailment.  The  wheel  base  of  the  car 
Is  46  In.,  the  axles  are  of  steel,  the  wheels  have  brass  bear- 


direct  connected  to  the  driving  axle  and  developing  314  h.  p. 
is  used.  The  equipment  of  the  car  includes  a  six-cell  multiple 
series  battery  with  a  double  waterproof  spark  coil  and 
timing  and  control  levers  operating  on  a  spark  and  throttling 
the  fuel  supply.  The  gasoline  tank,  located  under  the  seat  «f 
the  car,  will  carry  a  fuel  supply  for  100  miles.  The  driving 
wheels  are  17  in.  in  diameter  and  the  guide  wheels  14  in. 
A  speed  of  from  three  to  20  miles  an  hour  may  be  main- 
tained. The  No.  2  car  weighs  375  Ibs. 


Figs.  3594-3609 


ACCESSORIES. 


495 


TRACK  CIRCUIT  AND  BONDING    TOOLS 


Fig-  3594-     Bond  Wires  in  Bundle. 
I 


Figs.  3595-3596.     Twist  Drills  for  -Bonding 


Machine  Fitted  to  Drill  Base  of  Rail.  Machine  Fitted  to  Drill  Web  of  Rail. 

Figs.  3597-3598.     Drilling  Machine   for  Rail   Bonding.     The  Union   Switch  &   Signal   Company. 


Fig.   3599-     Chuck    for   Drilling   Ma- 
chine.    Railroad.  Supply 
Company. 


Fig.  3600.     Buda  Wilson  Drill.     Un 
Fig.    3604.      Channel    Pin    Gauge.        der  Qutch      The  Buda  Company 

Bryant  Zinc  Company. 


Fig.  3605.     Channel  Pin. 


Figs.  3602-3603.     Channel   Pin   Set 

and  Punch.     Bryant  Zinc 

Company. 


Fig.  3601.   Buda  Wilson  Drill.    Hook 

Over  Top  of  Drill.     The  Buda 

Company. 


Fig.   3606.      Small    Channel    Pin    Drift    Punch. 


Fig.   3607.      Channel    Pin   Set. 


Fig.    3609.      "Boot    Leg"    Channel 
Pin     and     Bond     Wire     in 
Rail.     Railroad  Sup- 
ply Company. 


Fig.  3608.     Channel   Pin  Drift  Punch. 


496 


ACCESSORIES. 


Figs.  3610-3627 


Figs.  3610-3611.     Bond  Wires  Outside  of  Splice  Bars;  Fastened  by  Bonding  Tubes. 


i**- 

o 

o  : 

I  o 

o 

o 

-y 

Fig.  3612.    Bond  Wire  Behind  Splice  Bar;  Fastened 
by  Rivets.  , 


Q O 


Q. 


Fig.  3613.     Bond  Wires  Outside  of  Splice  Bar;  Fast-  ,-,.  c 

6    °     °  ,  _.  Figs.   3616-3618.      Standard   Rail   Bond.      Oregon 

ened  by  Channel  Pins.  c,         T  . 

Short  Line. 


JL_1 

O 

o  ; 

i  o 

Q 

JU 

Fig.  3614.     Bond  Wire  Outside  of  Splice  Bar;  Fast- 
ened by  Rivets. 


O      O 


Fig.  3615.     Bond  Wires  Behind  Splice  Bar;  Fastened 
by  Channel  Pins. 


P.    &    M.    BOND    WIRE    PROTECTORS. 

The  P.  &  M.  Co.  makes  three  styles  of  bond  wire  protectors, 
each  of  which  has  two  types,  one  holding  the  wires  below 
the  track  bolt  and  the  other  ab.ove.  The  protectors  holding  the 
wires  below  the  bolts  are  best  adapted  for  use  where  the 
bond  wires  are  applied  on  the  gage  side  of  the  rail  and  the 
flange  clearance  is  not  great  enough  to  allow  the  wires  to 


Type  A,  Style  3.  L f~~  Type  B,  Style  3. 

Figs.    3619-3620.      Bond    Wire    Protectors.      P.    &   M. 
Company. 

be  placed  above  the  bolts.  Style  1  has  an  elliptical  hole,  which 
fits  snugly  over  the  neck  of  the  bolt,  and  is  best  suited 
for  use  on  new  work  or  when  renewing  track  bolts,  as  it  must 
be  applied  over  the  end  of  the  bolts.  Style  2  is  designed  to  be 


Figs.  3621-3626.     Bond  Wire  Protectors  Showing  Methods  of  Application.     P.  &  M.  Company. 


applied  without  entirely  removing  the 
The  elliptical  hole  provided  in  Style  1  is 
slotted  to  slip  over  the  smaller  dimension 
of  the  bolt  neck,  being  held  firmly  in  place 
when  rotated  90  degs.  Style  3  is  designed 
for  application  independent  of  the  track 
bolt  and,  therefore,  can  be  used  both  for 
bond  wires  and  boot-leg  connections.  It 
held  in  place  by  a  9-32-in.  rivet,  driver 
in  a  hole  drilled  with  a  9-32-in.  bondir 
drill. 


Fig.  3627.     Type  B,  Style. I,  Bond  Wire  Protectors  in  Service. 

Company. 


P.  &  M. 


Figs.  3628-3637 


ACCESSORIES. 


497 


TRACK  AND  PIPE  LINE  INSULATION 


KEYSTONE    INSULATED   RAIL  JOINTS. 

The  special  feature  of  the  Keystone  insulated  rail  joint  is 
that  there  is  a  metal  filler  under  the  rail  head,  which  Increases 
the  area  of  Insulating  material,  and  receives  the  shock  from 
passing  trains. 

The  filler  and  angle  bar  are  of  rolled  steel.  The  angle  bar 
section  Is  such  that  it  makes  the  joint  as  strong  to  resist  both 
vertical  and  horizontal  stresses  as  is  the  non-insulated  joint. 


Fig.  3628.     Keystone  Rail  Joint.     The  Union  Switch  & 
Signal  Company. 

the  breaking  of  rails  through  the  bolt  holes  at  insulated  joints ' 
is  a  more  frequent  occurrence  with  forms  of  joints  that  do  not 
provide   efficiently   against   the   vertical   movement   of  the   rails 
with  relation  to  each  other. 

The  only  material  used  other  than  steel  Is  Insulating  fibre, 
the  area  of  which  Is  such  that  the  pressure  per  square  inch 
upon  It  is  low  as  compared  to  the  pressure  between  the  ordinary 
angle  bar  and  the  rail.  This  gives  a  rigid  backing  against 
which  the  bolts  may  be  firmly  tightened  and  remain  so;  and 
against  which  the  shock  of  passing  wheels  does  not  settle  the 
"running  on"  end  of  the  rail  nor  allow  the  "running  off"  end 
to  kick  up,  thereby  wearing  out  the  fibre. 

The  Joint,  when  placed  In  a  curve,  bends  to  the  rails  like  an 
ordinary  angle  bar  so  that  the  curve  of  the  rail  Is  uniform.  It 


is  applied  like  an  ordinary  angle  bar  and  as  no  part  of  It  goes 
between  the  base  of  the  rail  and  tie,  no  dapping  or  lowering  of 
the  ties  is  required.  Water  and  dirt  do  not  work  in  between 
the  fibre  and  the  metal  to  cause  an  electrical  break-down  of 
insulation  because  there  Is  no  movement  between  the  part*. 

The  Keystone  insulated  joint  is  illustrated  in   Mg.   3628.     It 
is   made  by  the  Union   Switch  &  Signal   Company. 


Figs.   3629-3630.     Insulated   Rail  Joint.     Railroad  Sup- 
ply Company. 


Figs.  3631-3632.     Mock   Insulated  Rail  Joint. 
Railway  Supply  Company. 


Buffalo 


FIBRE 


4  BOLT  FIBRE  INSULATION   84«-i 


STEEL 


«  BOLT  FIBRE  INSULATION   •*«-! 


Figs.  3633-3637.     Insulated  Rail  Joint  and  Fibre  Parts.     Railroad  Supply  Company. 


ACCESSORIES. 


Figs.  3638-3652 


Figs.  3638-3639.     Details  of  Mock  Insulated  Rail  Joints. 


Names  of  Parts  of  Mock  In- 
sulated   Rail    Joints ; 

Figs.  3638-3639. 
C    Auxiliary   Rail   Riveted 
to    Steel    Plate    and 
Filler 
D    Bolt 

E    Steel  Angle  Bar 
F    Iron  Strap 
G    Iron  Washer 
H     Inside  Wood 
I      Fibre  Stri[> 
J      Outside  Wood 


Fig.   3640.     The    "Continuous"   Joint.     The    Rail   Joint 
Company. 


K    Fibre  Mat  (Sole  Plate) 
L    Insulating  Bushing 
M    Fibre  Angle 

I'igs.   3643-3644.      Insulated   Rail   Joint.     Railroad    Supply 
Company. 


Fig.  3641.      The  Weber  Joint;    Wooden   Splices.      The 
Rail  Joint  Company. 


© 

(O) 

., 

Figs.  3645-3646.     Switch  Wedge  Countersunk  for 
Wood  Screws. 


Fig.  3642.     The  Weber  Joint;  Steel  Splices.     The  Rail 
Joint  Company. 


J3r- 


Figs.  3649-3650.     Switch  Wedge  with  Wooden  Base. 


a 

r 


O 

O 

Figs.  3647-3648.     Wedged  Switch  in  Track  Circuit.        Figs.  3651-3652.   Switch  Wedge  Drilled  for  Lag  Screws. 


Figs.  3653-3674 


ACCESSORIES. 


499 


Figs.  3653-3654.     Insulated   Rod  with    Special   Jaw  for 

Rocker  Shaft  Connection.     The  Union 

Switch  &  Signal  Company. 


Names  of  Parts,  Insulated  Rod  with  Special  Jaw;  Figs. 
3653-3654- 

1  Threaded  Rod  6  Fibre  Bushing 

2  Special  "T"  Jaw  7  Fibre  Plate 

3  Bolt  and  Nut  8  Screw  Jaw 

4  Steel  Washer  9  7am  Nut 

5  Fibre  Washer 

Names  of  Parts,  Pipe  Line  Insulation;  Figs.  3655-3656. 

1  Tang  End  4  Fibre  Plate 

2  Bolt  5  Fibre  Bushing 

3  Splice  Plate 


o   a   all  a   a  aim 


\ 


2  35 

n         r-i        n  /  t—i 


Figs.  3655-3656.     Pipe  Line  Insulation. 


753 

/__y x. 


33 


JB> 2~s^3      *v 


Figs.  3657-3658.     Pipe  Line  Insulation. 


Figs.  3659-3660.    Adjustable  Insulated  Switch  Rod.    The 
Union  Switch  &  Signal  Company. 


7      8       l 


S 


Figs.  3661-3662.     Insulated  Lock  Rod. 


00 


*- 


/.  » 

fi  2  O  <j 

Figs.  3663-3664.    Adjustable  Insulated  Front  Rod. 


Names  of  Parts,  Pipe  Line  Insulation;  Figs.  3657-3658. 

1  Tang  End  5  Wrought  Washer 

2  Bolt  and  Nut  6  Fibre  Bushing 

3  Spring  Washer  7  Ft&r?  Plate 

4  Ft'&r^  Washer 

Names    of    Parts,    Adjustable    Insulated    Switch   Rod; 
Figs.  3659-3660. 

1  Threaded  Piece  5  Splice  Plate 

2  Jam  Nut  6  Fibre  Plate 

3  Socket  Rod  7  Fibre  Bushing 

4  Plain  Rod  8  Bolt 

Names  of  Parts,  Insulated  Lock  Rod;  Figs.  3661-3662. 

1  Threaded   Rod  5     Fibre  Bushing 

2  Tappet  6    Bolt 

3  Splice   Plate  7     Screw  Jaw 

4  Ft'&r*  F7ate  8    7am  Nut 

Names  of  Parts,  Adjustable  Insulated  Front  Rod;  Figs. 
3663-3664. 

2  Lug  Rod  6  Fibre   Washer 

3  Solid  Jaw  7  Fibre  Bushing 

4  Splice  Plate  8  Screw  Jaw 

5  Fi&n?  Plate  9  7om  AT«f 


sr»  iWnrt  iij  i 

[SOLID   JAW  END]        HALF    RODS.          [TANG  END] 
(ro«Mi>) 


[WITH  SOLID  JAW  HANG  END]   ASSEMBLY.    [WITH  TANG  ENDS  ONLY]] 


•€» 


2-0' 1 


Figs.  3665-3674.  R.  S.  A.  Standard  Pipe  Line  Insulation. 


500 


ACCESSORIES. 


Figs.  3675-3690 


•  —4 


fasu/afion^ 


.  i/uni  ii*fe.    tti't  :tt,J 

Enlarged      \  ^pj.k_j          X_JT       T^J          "~:*\ 

Detail.          \     ^-"    K 15— >l 

Cast  Sfee/  Intermed/afe  Block 

Figs.    3675-3677.      Insulated    Switch    Rod   and    Details. 
Pennsylvania   Railroad. 


Figs.  3678-3679.     Insulated  Joint  for  Welding  into  Tie 
Plates,  etc.     The  Union  Switch  &.  Sig- 
nal  Company. 


Vu/caniced 
Fiber  •>. 


—Iron  Mbrs/ier 


F/ter 


'Fiber  Plate 


__  .   j  *~  Fiber  Bashinf^      _  j 

-/**--  --------  <$--    -----*^V-H 


Figs.   3680-3682.     Insulated   Switch  Rod  with   Lug  for      Fig.  3683.     Method  of  Insulating  Switch  Rods  and  Tie 
Throw  Rod.     Pennsylvania  Railroad.  Plates.     Southern   Pacific-Union   Pacific. 


Figs.  3684-3686.     Insulated  Switch   Rod   Details. 


\                                                                                                           \  i          i  1 

Q'*  )    ©@      •<§><§><§> 

TadTM 

@©    (     Q 

t 

'V'     •,/''  •  /  *'  ''  i  ^TT^        ' 


Ffber  Bushing. 
Figs.  3687-3688.    Adjustable  Insulated  Switch  Rod.     Chicago,  Milwaukee  &  St.  Paul. 


Fig.  3689.     Pipe  Line  Insulation.     H.   W.  Johns-Manville   Company.    Fig.    3690.      Axle    Insulation    for    Hand 

Cars.     Railroad  Supply  Company. 


Figs.  3691-3695 


ACCESSORIES. 


TRAIN  STOPS 


Fig.  3693.     Automatic  Train  Stop.     Boston 
Elevated. 


Figs.    3691-3692.      Electro-Pneumatic    Train     Stop.      The 
Union  Switch  &  Signal  Company. 

Names  of  Parts,  Electro-Pneumatic  Train  Stop;  Figs. 
3691-3692. 

1  Counterweight  Box  8    Piston  Rod 

2  Counteriveight  Box  Cover 

3  Cylinder 

4  Piston 

5  Front  Cylinder  Head 

6  Back  Cylinder  Head 


7    Cylinder  Guard 


9  Counterweight 

10  Shaft 

11  Shaft  Bearing 

12  Bearing  Plate 

13  Stop  Arm 

14  Connecting  Rod 


Fig-    3694.      Electro-Pneumatic    Automatic    Train 
Stop.    The  Union  Switch  &  Signal  Company. 


Fig.  3695.     Operating  Circuits  for  Automatic  Train  Stops. 


502 


ACCESSORIES. 


Figs.  3696-3700 


A  •  LAMP    SOCKET 

B  -  CYLINDER 

C  •  FUSE 

D  .  CONTACT   SPRING 

E  -  TRIPPER    ARM 

F  •  SHAFT 

G  -  COLLA'R 
H  -  SLACK  'WIRE  BOX 
I  •  SHAFT  BEARING 
K  •  COUNTER  WEIGHT 

L  -  PISTON 


Fig.   3697.      Kinsman   Electro-Pneumatic    Stop    With   6 
Point  Circuit  Breaker. 


Fig.   3696.     Electro-Pneumatic   Train    Stop.      Kinsman 
Block  System  Company. 


STOP   LIGHT   FUS 
CONTACT    TIP 
CONTACT    BLOCK 


Fig.   3698.     Automatic   Stop.     Kinsman   Block   System      FiS-  3699-     Kinsman   Stop  with  2   Point   Circuit   Breaker 
Company.  f°r  Use  with  G.  R.  S.  Apparatus. 


Fig.  3700.     Circuit  for  Automatic  Stop. 


Figs.  370I-3731 


ACCESSORIES. 


503 


TRUNKING  AND  CONDUIT 

TRUNKING 


18 


19 


17 


13 

Figs.  3701-3721.     Types  of  Trunking  and  Capping. 

Ho/e  ro  be  exact 


19  Grooved  Trunking  with  i"  x   i" 

Opening 

20  Grooved  Trunking  ivith  iY2"  x  2" 

Opening 

21  Grooved.  Trunking  with  i"  x  3" 

Opening 


Names    of   Parts,    Trunking;    Figs. 
3701-3721. 

1  Grooved  Trunking  with  i"  x  i" 

Opening 

2  Grooved   Trunking  with  i"  x  2" 

Opening 

3  Grooved  Trunking  with  i"  x  3" 

Opening 

4  Grooved   Trunking  with    \V2"   x 

il/2"  Opening 

5  Grooved  Trunking  zvith  2"  Open- 

ing 

6  Grooved  Trunking  with  2%"  and 

i"  Opening 

7  Grooved  Trunking  ivith  4"  Open- 

ing 

8  Grooved   Trunking  with  4"   and 

i"  Opening 

9  Bo.ved   Trunking   with   2"   x    5" 

Opening. 
10    Boxed    Trunking   with   2"   x    7" 


11  Boxed    Trunking  with  4"   x    7" 

Opening 

12  Boxed  Trunking  with  5"  x   12" 


13  Bo.ved   Trunking  with  5"  x   16" 

Opening 

14  Grooved  Trunking  •with  2%"  and 

21/-"  Opening 

15  Grooved  Trunking  with  2^/2"  x  6" 


1  6     Grooved  Trunking  with  2"  x  3" 
Opening 

17  Grooved    Trunking  with    i^"    x 

2M$"  Opening 

18  Grooved   Trunking  with    i^"   x 

i^"  Opening 

Directio 
afJraffk. 


Figs.  3722-3723.    Standard  Bootleg  and  Wire  Connections  to  Rail. 
New  York  Central    &  Hudson  River. 


•77?/s  /rrtfy  be  varied  To  not  less  than  &  where  t/es  are  c/ose. 


STAn/OAffO. 


'op  of  flange  of  rail. 

/O  BdlS  insu/ated  copper  wire 


6  B<&€>  Copper  Clad  steel  wire. 

1  as  shown. 

Figs.  3724-3731.     Standard  Bootleg,  and  Details  of   wire  Joints  and  Connections.     Oregon   Short  Line. 


504 


ACCESSORIES. 


Figs.  3732-3796 


ORDINARY  JOINT 


ORDINARY  A,ND'T'&'L'  JOINTS 

SCALE  i'-r 


Figs.  3732-3772.     Standard  Bootleg  and  Trunking  Connections.     Atchison,  Topeka  &  Santa  Fe. 

Figs.    3732-3772    show    the    Atchison,    Topeka    &    Santa    Fe  this  road  is  cypress  south  of  Temple,   Texas,   and  redwood,  or 

standard   construction   details   for   grooved  trunking ;   and  Figs.  Port  Orford  cedar  on  all  other  parts  of  the  system.    Figs.  3732- 

"8773-3796  show   the  standard  construction  details  of  the  same  3772  also  show  the  details  for  standard  bootleg  to  rail  connec- 

road  for   built   trunking.      The  .material    used  for   trunking   on  tions  and  for  a  switch  box  bootleg. 


PLAIN  JOINT  CROSS  SECT 


\                K 

v     •* 

JOKT  of  rcorourr  TO  «*(.'  TRVJNKIMO 


Figs.    3773-3796.     Standard    Trunking    Connections.      Atchison,    Topeka    &   Santa  Fe. 


Figs.  3797-3821 


ACCESSORIES. 


505 


r-Ma/n  TrunK/ng. 


f- Capping. 


TrunKing. 
Corner  TrunK/'nj. 


£±S 


Bottom  Boara1. 

-*(//!- 


9"  — 


ft- 


*   • 

*tf 

Ws 
ER 

DETAILS. 


Dr//ljgho/es  for60c/.nai/s. 

Pcr/nt  with  2  coats  of  black  paint. 

MA  TER/AL. 
Cypress  or* /common  Southern  P/ne,  sfraight- 

B*ANGH  TRUCKING.        gra/necj.  to  be  we//  seasoned  and  free  from  foose 
DETA/LS. 

Knots  and  shakes.  Surface  a//  sides. 

Figs.   3797-3807.     Trunking   Branch   and    Corner    Connections,    Southern  Railway. 


Wv 


Us*  where  Main  and  Branch  ore  same  srie 


Figs.  3810-3816.     Trunking   Connections.     Southern   Railway. 


\\ 

5  |  j 


Figs.  3808-3809.   Pipe 
Conduit      Connec- 
tions     to      Wood 
Trunking.  New 
York  Central. 


Fig.     3817.       Trunk- 
ing Hole  for 
Drip. 


Fig.  3818-3820.  Junction   Box  in 

Line  of  Trunking.     New 

York    Central. 


Fig.    3821.     Reinforced    Concrete    Junction    Box. 
C.   F.   Massey   Company. 


ACCESSORIES. 


Figs.  3822-3834 


CONDUIT 


Fig.  3822.     Screw  Joint  Fibre  Conduit. 


Fig.  3823.     Sleeve  Joint 


Fig.  3824.    Junction  Box 


Figs.  3831-3833.     Standard  Bends. 

Figs.    3822-3833.      Standard    Fittings    and    Connections 
Orangeburg  Fibre  Conduit.    Fibre  Con- 
duit Company.  Fig.   3834.     Installation  of  Orangeburg  Fibre   Conduit. 


Figs.  3835-3850 


ACCESSORIES. 


507 


ORANGEBURG    FIBRE    CONDUIT. 

In  the  process  of  manufacturing  Orangeburg  Fibre  Conduit, 
wet  wood  pulp  or  fibre  is  wrapped  in  a  minutely  thin  film  upon 
a  forming  mandrel,  under  pressure,  until  the  desired  thickness 
of  wall  is  obtained.  The  individual  librcs  become  felted  and 
form  a  solid,  homogeneous  wall.  Taken  off  the  mandrel,  the 
wet  pulp  structure  is  subjected  to  a  drying  process,  after 
which  it  is  placed  in  a  vat  of  liquid  compound.  This  com- 
pound is  a  preservative  and  is  also  insulating  and  water- 
proofing. It  thoroughly  permeates  the  entire  structure,  so  that 
after  treatment  the  wall  of  the  conduit,  when  cut,  presents 
a  strong  resemblance  to  hard  rubber.  The  ends  are  cut  in 
a  lathe  to  make  a  socket  joint,  sleeve  joint  or  screw  joint 
thread,  as  may  be  desired. 


AMERICAN    BITUMrXIZED    CONDUIT. 

American  bituminized  fibre  conduit  is  made  up  of  a  series 
of  laminations  of  thoroughly  saturated  fibre  alternating  with 
layers  of  an  insulating  compound  that  is  impervious  to  moisture 


Figs.  3835-3839.     Standard  Sections  and  Fittings  of 

Bituminized  Fibre  Conduit.     American 

Conduit  Company. 

and  has  a  puncture  strength  of  40,000  volts  for  a  thickness  of 
1/10  in.  In  the  %-in.  wall,  which  is  standard  for  all  sizes 
above  1%  in.,  there  are  26  of  these  laminations  securely 


Figs.  3840.     Reinforced  Concrete  Trunking  and 
Junction  Box.     C.  F.  -Massey  Company. 


The  same  materials  and  general  process  are  employed  in 
producing  bends  of  various  degrees  and  radii,  "S"  bends,  tees, 
elbows,  crosses,  couplings  and  junction  boxes,  with  the  varying 
number  of  outlets. 

Orangeburg  Fibre  Conduit  is  waterproof  and  is  not  affected 
by  acids,  alkalies  or  gases.  It  contains  nothing  that  will 
injure  the  insulation  of  wires,  and  prevents  electrolysis.  Its 
insulating  qualities  enable  it  to  withstand  a  puncture  test  of 
25,000  volts  a.  c.  it  is  not  inflammable.  Ir  a  steady  flame  is 
applied  to  it,  it  will  burn,  but  the  flame  will  not  spread  and 
when  the  heat  is  taken  away  it  immediately  stops  burning. 


cemented  together.  A  puncture  test  of  50,000  volts  is  guar- 
anteed. The  absorption  of  moisture  by  this  conduit  after  it  Is 
laid  is  eliminated  by  passing  the  laminations  through  the 
saturating  compound  one  at  a  time,  thus  insuring  thorough 
penetration. 

The  conduit  is  made  in  sizes  from  one  In.  to  eight  in- 
internal  diameter.  The  one  in.  and  1%  in.  sizes  are  made  hi 
five  ft.  lengths  and  have  a  joint  %  in.  long.  The  larger  sizes 
are  made  in  seven  ft.  lengths  with  a  %  in.  joint.  Fittings  of 
every  description  for  signal  work  are  made  by  the  same 
process  as  that  employed  in  the  manufacture  of  the  conduit. 


1 

F 

T 

1 

_J— 

_ 

- 

I5E 

~%j 

1 

*« 

, 

i 

*»!«» 

i' 


a-  /rewt-e..         I*-2-*— -I 
Figs.  3841-3850.     Standard  Sections  and  Fittings  Bituminized  Fibre  Conduit.     American  Conduit  Company. 


ACCESSORIES. 


Figs.  3851-3867 


BOOTLEGS  AND  CONNECTIONS 


n  n  nn  n  n  n  n  n.n 


CLO 


E5 

=*=-?* 

^ 

ltd             W 
3\.              f' 

ks= 

=sH 

•*^Wesf          £crsf-*- 

«y          V 

A/u/rrbering  of  Wires. 

1^1            W 

LT 



~DTTU 

u  u  u  u 

u  uu  u 

U 

Fig-  3851.    Standard  Track  Wiring  and  Trunking  Run  at  Signal  Location  or  Cut  Section.    Southern  Pacific- 
Union  Pacific. 


No£86agr 

" 


cnrs 
X/vi 


inc,  3  >Syvare. 

NalOB&S.  6age,  Rubber 
Covered  Copper  Mrc. 


I  \t--2"-^-3aUer Joint. 

No£B.W6.EB.B. 
6a/vamzecf  ttfre. 


u 


Figs.    3852-3854.      Bootleg   and    Wire 

Connection  to  Rail.    Union 

Pacific. 


Figs.  3855-3857.     Details  of  Bootleg  and  Connection  to  Rail 


QaM  /roTHv/'re  No.  3 


~/Vo.  9  /nsL//ated  Copnpr  W/re 

Fig.  3858.     Detail  of  Wire  Bootleg.     Michigan  Central. 


Brace 


^BondWire 


'Co/ping 


Side  Toward  /fa/7. 


Cfiarrne/Pin- 


=ia 


,-BondWire 


^•Trun/nng 


^^So/deredJanf 


Front  of  ffoofl£g  6a/v5heet  InonCover 

Figs.  3859-3863.    Bootleg  and  Wire  Connections  to  Rail. 


SATUWTCD  EXTRH  ME4VY  81 


Figs.  3864-3865.     Wire  Insulation. 


Bottom  View. 

Figs.  3866-3867.     Malleable  Iron  Boot- 
leg Cap.   Long  Island  Railroad. 
T.  George  Stiles  Company. 


Figs.  3868-3883 


ACCESSORIES. 


509 


Figs.  3868-3869.    Standard  Bootleg  and  Wire  Connections  to  Rail.    Illinois  Central. 


Figs.    3870-3875.      Successive    Stages    in 
Connecting  Iron  Bond  Wire  to  Cop- 
per Lead  to  Make  Wire  Bootleg. 
The  Union  Switch  &  Signal 
Company. 


Figs.  3876-3879-  Wooden 
Trunking  Stake  and  De- 
tails. Chicago,  Milwau- 
kee &  St.  Paul. 


1 


Figs.  3882-3883.     Location  of  Oil  Tank,  and!  Pump  at 
Figs.  3880-3881.     Standard   Bootleg  and  Wire  Connec-  Interlocking  Tower.     New  York  Central 

tion  to  Rail.     Southern  Pacific.  &  Hudson  River. 


ACCESSORIES. 


Figs.  3884-3899 


Fig.  3884.     Insulated  Twisted  Wire. 


Fig.   3886.     Solid    Copper   Conductor ;   Insulated 
Plain. 


Fig.   3885.      Insulated   Flat   Pair. 


Fig.  3887.     Same  as  Fig.  3886,  with  Braid. 


Fig.    3888.      Same    as    Fig.    3886,    Taped. 


Fig.  3890.     Solid  Copper  Conductor ;  Insulated  and 
Lead  Covered. 


Fig.  3892.     Solid  Copper  Conductor;  Insulated  and 
Lead  Covered. 


Fig.  3889.     Same  as  Fig.  3888,  with  Braid. 


Fig.  3891.     Solid  Copper  Conductor;  Insulated  with 
Two  Tapes  and  One  Braid. 


Fig.  3893.     Stranded  Copper  Conductor ;  Insulated 
and  Lead  Covered. 


Fig.  3894.     37-Conductor  Aerial  Cable. 


Fig.       3895.         Seven-Con-      Fig.     3896.       Single     Con- 
ductor Submarine  ductor  Submarine 
Cable.  Cable. 


Fig.  3897.     Armored  Submarine  Cable. 


Fig.     3898.       2O-Conductor     Sub- 
marine Cable,  with  Com- 
mon Return. 


Fig.  3899.     i9-Conductor  Aerial  Cable 


ACCESSORIES. 


KERITE. 

Covering. 

Kerite    is    an    insulation    for    electrical    conductors.      It    is    a 

4.     The    conductor    shall    be    covered    with    two    (2)     closely 

homogeneous  combination  of  crude  kerite  and  upriver  fine  para 

woven   braids  of   cotton,   each   of  which  shall   not  be   less   than 

rubber.       Unlike     rubber    mineral     insulations    its     life    is    not 

one-thirty-second    (1-32)    inch  in  thickness.     This  braiding  shall 

limited  to  that  of  the  rubber  ;  the  crude  kerite   (which  is  itself 

be    thoroughly    saturated    with     a     permanent     weatherproofing 

an   active   insulating  compound)    serving  to  prevent   drying  out 

compound,    which   shall   be   applied   in  sufficient  quantity   to   fill 

of    the    insulation,    diminution    of    insulating    qualities    and    the 

all  interstices  and  form  a  continuous  coating  over  the  covering. 

injurious    effects    of    deteriorating    agencies.      Kerite    was    origi- 

5.    The    temperature    of    the    saturating   compound   shall    not 

nated  about  1850.     It  is  extensively  used  for  railway  signal  work 

be    more   than   300    degrees   Fahrenheit,   or   such   as   will  soften 

and    other    purposes    where    durability    and    permanency    of    in- 

the   wire    more    than    is    allowable    with    the    elastic    limit    re- 

sulating properties  are  required. 

quired.     The   wire  must   remain   in  the   compound   and  must  be 

closely   stripped   so   that  there  shall  not  be   any  excess   of  com- 

OKONITE. 

pound    beyond   what    is   absorbed   by   the   cotton   and  the   filling 

Okonite   is   a   rubber   compound  for   insulating   electrical   con 

of  the  interstices  of  the  same,  leaving  a  good,  smooth  surface. 

ductors.     It  is  composed  of  pure  "Fine  Para"   rubber  and  dry 
mineral  matter,  these  materials  being  combined  by  an  exclusive 
formula  in  the  proportion  of  30  per  cent  rubber  to  70  per  cent 

6.     The  compound  shall  be  insoluble  in  water,  shall  not  melt 
when    the    finished    wire    is    subjected   to   a   temperature   of   one 
hundred    and   twenty-five    (125)    degrees    Fahrenheit,    and    shall 

mineral  matter.     The  method  of  manufacture  is  designed  to  re- 

STRANDED    CONDUCTORS. 

tain  all  the  inherent  properties  of  the  rubber  and  to  increase  its 
durability   for   insulating  purposes    to   the  greatest   possible  ex- 
tent.    Okonite  insulation  is  distinguished  by  a  single  ridge  run- 
ning the  length  of  the  wire  to  which  it  is  applied. 

Approximate                                   Number                                      Actual 
Size,  B.  &  S.                                       of                                       Circular 
Gauge.                                       Strands.                                    Mils. 

2000000                                              127                                          2000250 

INSULATION    RESISTANCES. 

1500000                                                91                                          1502592 

1000000                                              91                                        1003275 

The    following     revised     table     of     insulation     resistances     in 

900000                                                91                                            900900 

megohms    per    mile    at    sixty    (60)    degrees    Fahrenheit   for    the 

800000                                                91                                             804076 

various  thicknesses  of  insulation  and  the  various  sizes  of  wire 

700000                                                          C1                                                      cocoon 

has    been    recommended    for    adoption    by    the    Railway    Signal 

i  wvuv                                                                        o  J.                                                                  D«7OOoy 

600000                                                61                                            597861 

Association  ; 

500000                                              37                                          506493 

400000                                                37                                            400192 

32            53745678 

350000                                              37                                          351722 

B.  &S.G.    64        32          64      32        64       ~3T       32       32       IF     ~32 

QOOOOO                                                              ^7                                                         ooQTftn 

0         900   1000   1200   1300   1500   1800   2000   2200 

ovww                                                3  i                                            jyy  i  uu 

1          1000   1200   1400   1500  1800   1900   2200   2300 

250000                                              37                                          248788 

0000                                                     19                                            211470 

2          ....    1000   1100   1400   1500   1600   1900  2200   2300  2600 

3         1100  1200  1500  1600  1800   2000   2300  2600  2700 

000                                                     19                                             167884 

4          1200   1400   1600   1800   1900  2200   2400  2700  2800 

00                                                     19                                            132468 

5         1300   1500   1700   1900  2000  2300  2600  2800   3100 

0                                                     19                                            105450 

6          1400   1600   1800   2000   2200   2600   2800  3100   3400 

1                                                     19                                               84018 

8          1400   1600   1900   2200   2300  2600   2800   3200   3500   3800 

19                                               66139 
3                                                       7                                               52274 

9         1500   1800   2000   2300   2600   2700   3100   3400  3600   3900 

10         1600   1900  2200  2400  2700   3000   3200   3600   3900   4200 

4                                                       7                                               41503 

12         1800  2200   2500   2800   3100   3200  3600   4000   4300   4600 

5                                                    7                                            33327 
6                                                       7                                               26047 

14         2200   2600   2800   3200  3500   3600   4200   4400   4800   5100 

8                                                       7                                               16464 

9                                                        7                                              12943 

In  the  manufacture  of  cables  where  the  conductors  are  com- 

10                                                      7                                               10374 

posed  of  a  number  of  wires,  it  is  necessary  that  the  wires  or 

12                                                        7                                                 6300 

strands    be   of   a    proper   size    to    give   a    perfect    lay    for    each 

14                                                        7                                                 4375 

conductor,  as  wires  of  exact  B.  &  S.  gauge  size  will  not  always 

16                                                       7                                                 2527 

give   a   perfect   lay,   and   there  has  been   developed  in   the  trade 

18-7  No.   26                                    7                                                 1778 

various    sizes    of   strands    of    wires    which    are    standard   in    the 

20-7   No.   28                                    7                                                 1113 

manufacture  of  stranded  and  flexible  conductors.     These  special 

21-7  No.  29                                  7                                                 889 

standard  sizes  of  strands  are  not  given  or  referred  to  in  cata- 

22-7 No.  30                                  7                                                700 

logues    intended   for   a   purchaser's   use,   but   should   a   cable  be 

ordered  with  conductors  of  a  size  requiring  strands  of  other  sizes 

than  the  manufacturer's  standard,  a  higher  price  is  charged  and 

FLEXIBLE  CONDDCTORS. 

longer   time  required  in  the  making  of  the  cable,  owing  to  the 

Approximate                          Number                                      Actual 

special   strands   that  have  to  be  procured.     It  is,  therefore,  ad- 

Size, B.  &  S.                                of                                          Circular 

visable  that,  when  ordering  cables  with  flexible  conductors,  these 

Gauge.                                Strands.                                       Mils. 

should    conform    to    the    requirements    of    the    following    tables. 

0000                                            37                                            210900 

which  differ  only  in  the  sizes  of  the  strands  used  and,  therefore, 

A  A  A                                                                               q  7                                                                               1COKTO 

in    the   flexibility    of    the    conductors. 

UUU                                                                               Of                                                                                lOOOlJI 

00                                            37                                            133200 

0                                            37                                            105894 

REVISED      SPECIFICATION      FOR     DOUBLE     BRAIDED,      WEATHERPROOF, 

1                                            37                                               83472 

HARD    DRAWN    COPPER    LINE    WIRE. 

2                                            37                                              66822 

General  Description. 

3                                            19                                               52364 

1.     The   intention  of   this    specification   is   to   provide  for   the 

4                                            19                                               41971 

furnishing   of    hard    drawn    copper    line    wire    which    is    covered 

5                                            19                                               33516 

with    a    double    thickness    of    weatherproof    braiding. 

6                                            19                                               26011 

Conductor. 

8                                            19                                               17011 

2.     The  wire  must  be  cylindrical   in  form,  free  from  scales. 

9                                            19                                               12844 

flaws,    inequalities,    splints    and    all    imperfections.      Each    coil 

10                                            19                                               10051 

must   contain  no  weld,  joint   or  splice. 

12                                            19                                                 6498 

Properties. 

14                                            19                                                 3990 

3.     The   mechanical   arid   electrical'  properties  '-Of  .the   finished 

16                                            19                                                 2508 

wire  must  be  in  accord  'With  the  following  requirements  : 

18-7  No.   26                        19                                              ]50t 

Breaking            Per  Cent       Conductivity 

not   crack  when   the   finished    wire   is    subjected   to  a   tempera- 

B. &  S.        Diameter       Strength,          Elongation       Per  Cent  of 

ture  of  ten   (10)    degrees  below  zero  Fahrenheit. 

Gauge.         in  Mils.         Pounds.          in  10  Inches.     Pure  Copper. 

7.     The    qualities    of   the   compound   and   the   method   of  ap- 

plication shall   be   such   as  not  to   injure  the  braided  covering 

6                  162                 1210                        1.12                        97 

or   the   wire. 

7                 144                  970                       1.08                       97 

8.     The   melting   and   freezing   tests   of   the   compound    shall 

8                 128                  779                       1.06                       97 

be  made  as  follows  : 

9                 114                   620                       1.04                      97 

Short  pieces   of   wire    shall    be    placed    on    a   piece   of   clean 

10                 102                  502                       1.02                       97 

white   glazed    paper   in   a    chamber  which    has   been   heated   to 

12                    SI                  319                       1.00                       97 

125   degrees   Fahrenheit,   this  temperature  to  be  maintained  for 

512 


ACCESSORIES. 


half  an  hour.  The  wire  shall  be  rejected  if  the  compound 
becomes  sufficiently  fluid  to  be  transferred  to  the  paper  on 
which  the  wire  was  placed  in  sufficient  amount  to  form  a  ridge 
perceptible  to  the  fingers  or  in  case  the  compound  is  absorbed 
by  the  paper  as  indicated  by  a  greasy  or  oily  spot. 

9.  The  finished  wire  shall  be  immersed  in  a  freezing  mixture, 
which    shall    show   a   temperature    of    ten    (10)    degrees    below 
zero  Fahrenheit  for  one-half    ( % )   hour,  and  if,  upon  removal, 
the    compound    so    contracts    (without   bending    sample)    as    to 
produce  cracks  in  its  surface,  the  wire  shall  be  rejected. 
Inspection  and   Tests. 

10.  The   purchaser   is   to   have  the   right  to   make   such   in- 
spection   and    tests    as    he    may    desire    of    the    materials    and 
of   the  wire,   at   any   stage  of   the   manufacture. 

11.  The  manufacturer  must  provide  at  the  mill  all  apparatus 
and  labor  for  making  the  required  tests  under  the  supervision 
of   the   purchaser.  , 

12.  Tests    shall    be    made    at    the   mill    or   on    samples    sub- 
mitted  by    the    manufacturer,    and    may   also   be   made   on   the 
wire   upon    its   arrival    at   destination.      The    wire    may    be    in- 
spected before  and  after  it  has  been  covered. 

13.  If  upon  arrival   at  destination   the  wire   does  not  meet 
the    requirements    of    this    specification,    it     will     be     rejected 
and   returned   to   the   manufacturer,   who   must  pay   all    freight 
charges. 

Packing   for  Shipment. 

14.  The  wire  shall   be  furnished   in   coils  of  not  less  than 
the  following  lengths  : 

0  to    4,  inclusive One-fourth   mile. 

6  to    8,  inclusive One-third  mile. 

9  to  12,  inclusive One-half  mile. 

15.  The   diameter   of   the  eye   of  the  coil   shall  be  not   less 
than    twenty     (20)     inches,    nor    more    than    twenty-two     (22) 
Inches. 

16.  Each  coll  shall  be  securely  bound  with  a  layer  of  heavy 
wrapping  paper  and  with  an  outside  wrapping  of  burlap,  with 
each   turn    of   burlap   overlapping  the   other   one-half    (%)    its 
width. 

17.  Each    coil    shall    have    the   weight,    length    and    size    of 
wire,    the   name    of    maker,    the   purchaser's   order    and   inspec- 
tion   number    and    the    proper    shipping    address    plainly    and 
Indelibly   marked  on   two    (2)    strong  tags.     One  of  these   tags 
shall  be  attached  to  the  coil  inside  the  burlap   and  the  other 
shall  be  attached  to  the  coil  outside  the  burlap. 

REVISED    SPECIFICATION    FOR   RUBBER    INSULATED    SIGNAL    WIRE   FOR 
CURRENT  OF   660  VOLTS  OR  LESS. 

Conductors. 

1.  Conductors  must  be  of  soft  drawn,  annealed  copper  wire 
having  a   conductivity   of  not  less  than   ninety-eight    (98)    per 
cent    of   that    of    pure    copper,    Matthiessen's    standard.      Each 
wire   forming  a    conductor   must   be    continuous,    without   weld, 
splice  or  joint  throughout  its  length,  must  be  uniform  in  cross 
section,    free   from    flaws,    scales    and    other    imperfections    and 
provided  with  a  heavy  uniform  coating  of  tin. 

Rubber  Insulation. 

2.  The    rubber    insulation    shall    be    made    exclusively    from 
pure   TTpriver,    fine,   dry   Para   rubber,    of   best   quality,    which 
has  not  previously  been  used  in  a  rubber  compound,  solid  waxy 
hydrocarbons,    suitable    mineral    matter    and    sulphur,    properly 
and    thoroughly    vulcanized.       Before    being    mixed    with    the 
other   ingredients  fhe  rubber   shall   be   thoroughly   washed   and 
dried. 

3.  The  insulation  must  be  homogeneous  in  character,  tough, 
elastic,  adhering  strongly  to  and  be  placed  concentrically  around 
the  wire. 

Braiding. 

4.  The  rubber  insulation  must  be  protected  with  one  layer  of 
closely  woven  cotton  braiding  at  least  one-thirty-second    (1-32) 
of   an   inch   thick,   saturated   with   a   black   insulating  weather- 
proof  compound   that   shall    be   neither   Injuriously   affected   by 
nor  have   Injurious  effect  upon  the  braid  at  a  temperature  of 
200   degrees   Fahrenheit. 

Acceptance. 

5.  The  product  of  those  concerns  only  will  be  accepted  who 
have    satisfied    the    purchaser    that    the    requirements    of    this 
specification   will   be   complied   with.     The   decision   as   to   the 
quality  of  the  wire  furnished  and  the  acceptance  of  the  same 
shall   be  made  by  the  purchaser. 

Tests. 

6.  The  manufacturer  shall  provide  at  his  factory  apparatus 
and   other   facilities   needed   for    making   the    required   physical 
and  electrical   tests.     The  manufacturer   shall   give  free  access 
to    the    place    of    manufacture    and    opportunity    for    Inspecting 
and  testing  the  product  at  all  stages  of  manufacture  to  show 
that  the  required  amount  and  quality  of  Para  rubber  and  other 
Ingredients  are  being  used  in  the  compound. 


7.  Tests   shall   be   made  from   samples  taken  from  any  part 
of  any  coil,  and   may  also  be  made  upon  the  finished  product 
Immediately  after  being  delivered.     If  the  requirements  of  this 
specification   are    not   met,    the   wire   will   be   rejected   and   the 
manufacturer    shall    pay    freight    charges    for    return    of    such 
material. 

8.  At    the   option   of    the   purchaser,    the   wire,    after   being 
tested,  shall  not  be  shipped  from  the  factory  until  an  analysis 
of  a  sample  has  been   made  by  a  chemist  chosen  by  the  pur- 
chaser,   and    the    results    of    such    analysis    as    interpreted    by 
the    purchaser    shall    be   sufficient    ground   for   rejection    should 
the  wire  or  insulation  not  conform  to  the  requirements  of  this 
specification. 

Physical   Test  of  Copper  Conductors. 

9.  Each  solid  conductor  must  stand  an  elongation  of  twen- 
ty-five   (25)    per  cent   of   its   length   in  ten    (10)    inches  before 
breaking,   and  must  be  capable  of  being  wrapped  six   (6)   times 
about  its   diameter  without  showing  signs  of  breakage. 
Conductivity   Test   of  Copper. 

10.  The  conductivity  of  the  copper  shall   be  determined  by 
measuring    the    resistance    of   a    length    of    the   wire    and    com- 
paring with  Matthiessen's  standard  of  copper  resistance. 

Test  of  Tinning. 

11.  Samples     of    wire    shall     be    thoroughly    cleaned     with 
alcohol   and   immersed   in  hydrochloric   acid   of   specific   gravity 
1.088  for  one   (1)    minute.     They  shall  then  be  rinsed  in  clear 
water    and    immersed    in   a    solution     of     sodium     sulphide     of 
specific   gravity    1.142    for   thirty-two    (32)    seconds    and    again 
washed.      This    operation    shall    be    repeated    three    (3)    times, 
and  if  the  sample  does  not  become  clearly  blackened  after  the 
fourth    immersion,    the    tinning    shall    be   regarded    as   satisfac- 
tory. 

12.  The    sodium    sulphide    solution    must   contain    an    excess 
of  sulphur    and   should   have   sufficient   strength   to   thoroughly 
blacken    a    piece    of    clean    un tinned    copper    wire    in    five    (5) 
seconds. 

Tests  of  Braiding. 

13.  A    six    (6)    inch    sample   of   wire   with    carefully   paraf- 
fined  ends   shall    be   submerged    in    fresh    water   of   a    tempera- 
ture of  70  degrees  Fahrenheit  for  a  period  of  twenty- four   (24) 
hours.     The  difference  in  weight  of  the  sample  before  and  after 
submersion   must  not  be  more  than   ten    (10)    per  cent  of  the 
weight    of    the    sample    before    submersion    less    the   weight    of 
the  copper  and  vulcanized  rubber. 

Physical  Tests  of  Rubber  Insulation. 

14.  A   sample   of  the  vulcanized    rubber   insulation   not  less 
than  four    (4)    inches  in  length  shall  have  marks  placed  upon 
it   two    (2)    inches    apart.      The   sample    shall   be    stretched   at 
the    rate    of    three    (3)    inches    per    minute    until    the    marks 
are  six    (6)    inches  apart  and  then  at  once  released.     One    (1) 
minute   after   such    release   the   marks   shall   not   be   over   two 
and  seven-sixteenths    (2   7-16)    inches  apart.     The  sample  shall 
then   be   stretched   until   the  marks   are  nine    (9)    inches  apart 
before  breaking. 

15.  The  tensile  strength  of  the  rubber  insulation  as  shown 
by    tests    made    on    a    carefully    prepared    sample   shall    be  not 
less  than  one  thousand   (1,000)    pounds  per  square  inch.     The 
sample,  for  five   (5)    minutes  before  and  as  near  as  practicable 
during  the  test,  shall  be  maintained  at  a  temperature  of  seventy 
(70)    degrees   Fahrenheit. 

16.  The   specific  gravity   of  the  rubber  insulation  shall  not 
be  less  than  1.75. 

Chemical  Tests  of  Rubber  Insulation. 

17.  The    insulation    shall    show   on   analysis    not   less    than 
thirty    (30)    nor  more  than  thirty-three   (33)   per  cent  of  pure 
Upriver,  fine,  dry  Para  rubber  of  best  quality ;  not  more  than, 
four    (4)    per   cent   of  waxy  hydrocarbons  consisting  of  refined 
paraffine   or   pure   ozokerite ;    not   more   than    0.7   per   cent   of 
free  sulphur ;  not  more  than  2.5  per  cent  total  sulphur ;  free- 
dom  from    all    foreign   matter,   and   the   mineral    matter   shalh 
be   such   as   will   not   have  a   deleterious   effect  on  the   insula- 
tion. 

Insulation 


Size 

Area  in 

Thickness 

Resistance 

Test  Voltage 

B.  &S. 

Circular 

of 

Megohms 

Alternating 

Gauge. 

Mils. 

Insulation. 

Per  Mile. 

Current. 

0 

105,592 

%"  wall 

900 

10,000 

1 

83,694 

%"      " 

1,100 

10,000 

2 

66,373 

%"      " 

1,200 

10,000 

4 

41,742 

3-32"      " 

1,100 

9,000 

6 

26,250 

3-32"      " 

1,300 

9,000 

8 

16,509 

3-32"      " 

1,600 

9,000 

9 

13,090 

5-64"      " 

1,500 

7,000 

10 

10,380 

5-64"      " 

1,600 

7,000 

12 

6,530 

5-64"      " 

1,900 

7,000 

14 

4,107 

6-64"      " 

2,100 

7,000 

16 

2,583 

1-16"      " 

2,100 

4,000 

18 

1,624 

1-16"      " 

2,400 

4,000 

ACCESSORIES. 


Klci--n-u-i.il  Tests  of  Rubber  Insulation. 

IS.  The  circular  mils  cross  section,  the  thickness  of  the 
rubber  insulation  (measured  at  the  thinnest  point),  the  mini- 
mum insulation  resistance  In  megohms  per  mile  and  the 
dielectric  strength  for  the  various  sizes  of  wire  shall  conform 
to  the  requirements  shown  on  the  opposite  page. 

19.  The   test   for    insulation    resistance   must   be    made    upon 
all  wire  after  at   least  twelve    (12)    hours'  submersion  in  water 
and,    while    still    immersed,    results    be    corrected    to    a    water 
temperature    of    sixty     (60)     degrees    Fahrenheit.      Tests    must 
be    made    with    the    wire    in    coils,    suitable    for    examination, 
and    before   the  application   of   braid   or    other    covering   with   a 
well-insulated    battery    and    galvanometer,    with    not    less    than 
one    hundred    (100)    volts    and    readings    must    be    taken    after 
one    minute's    electrification.       The    test    voltage    must    be    ap- 
plied   to    the    completed    length    of    wire    before    the    insulation 
test    for    a    period    of   five    (5)    minutes,    using   alternating   cur- 
rent from  a  generator  and   transformer  of  ample   capacity. 

Coils 

20.  The    wire    shall    be    furnished    in    coils     of     th?     length 
named  for  the  following  sizes  of  wire  : 


B.  &  S.  Gauge. 
No.  14 
No.  12 
No.  10 
No.  8 
No.  6 


Length  in  Feet. 
2,000 
1,500 
1,500 
1,500 
1,000 


21.  Twenty    (20)    per    cent   of   the   coils   will   be   accepted   if 
five   hundred    (500)    feet  long  or  over,   or   of   any   length   where 
a    coil     submitted   for    inspection    and    testing    has    been    cut    to 
secure  a  sample  for  testing. 

22.  The    inside    diameter    of    a    coil    shall,    unless    otherwise 
specified,   be   not   less    than    twenty    (20)    or   more    than   twenty- 
two    (22)    inches. 

1'acking  for  Shipment. 

23.  The  wire   shall   be  shipped   in   reels  or   coils  as   directed 
by   the   purchaser. 

24.  If    shipped    on    reels    they    shall    be    amply    strong    and 
the    wire    shall    be    protected    by   lagging    to    prevent    injury    in 
transportation.      A    tag    must    be    placed    inside    of    the    lagging 
and    a   stencil    on    the   outside    of   each    reel    giving   the   weight, 
the    length    of    each    piece    of    wire,    the    size    of    the    wire,    the 
name  of  the  manufacturer  and   purchaser's   order  or   inspection 
number  plainly   marked. 

25.  if    shipped    in    coils,    each    coil    shall    be    securely    bound 
with    a    layer    of    heavy    wrapping    paper    and    with    an    outside 
wrapping   of   burlap,   with   each   turn   of   burlap   overlapping  the 
other  one-half    ( \(> )    its  width. 

26.  Each    coil    shall    have    the    weight,    length    and    size    of 
wire,    the   name    of  maker    and    purchaser's   order   or    inspection 
number  plainly   and   indelibly   marked   on   two    (2)    strong   tags. 
One  of  these  tags  shall  be  attached  to  the  coil  inside  the  burlap 
and  the  other  shall   be  attached  to  the  coil  outside  the  burlap. 

SPECIFICATION    FOR   AERIAL    BRAIDED    CABLES    FOR    CURRENT    OF    660 
VOLTS    OR    LESS. 

General. 

1.  The    cable    brought    under    this   specification    will    be    used 

for current  at 

volts,   and   shall   be 

feet  in  length. 

2.  All    workmanship    and    material    shall    be    first-class    and 
the    best  of   their   respective  kinds,   and   shall   be   in   full  accord 
with    the    best    modern    electrical    and    mechanical    engineering 
practice. 

Form  of  Cable. 

3.  The  cable  shall   consist   of 

conductors   insulated  with   rubber  and   stranded  into  cable  with 
jute    laterals    to    make    round.      The    whole   shall    be   taped    and 
the  core  thus  formed  shall  be  wrapped  with  jute  covered  with 
a   closely-woven  braid,   as   herein  specified. 

Conductors. 

4.  Conductors    shall    be    of    the    following    sizes    and    num- 
bers : 

Approximate 
Nearest  Size 

Number   of     B.  &  S.  Gauge      Number   of      Size   of     Actual  C.  M. 
Conductors.  Each  Strands.         Strands,    of  Conductor. 

Conductor. 


5.  Conductors  must  be  of  soft-drawn,   annealed  copper  wire, 
having   a   conductivity    of   not    less    than   ninety-eight    (98)    per 
cent    of    that    of    pure    copper,    Matthiessen's    standard.      Each 
wire    forming    a    conductor    must   be    continuous,    without   weld, 
splice    or    joint    throughout    its    length,    must    be    uniform    in 
cross    section,    free   from   flaws,   scales  and   other   imperfections, 
and   provided    with    a    heavy    uniform    coating    of    tin. 

ff libber    Insulation. 

6.  The    rubber    insulation    shall    be    made    exclusively    from 
pure    Upriver,    fine,    dry    Para    rubber    of   best    quality,    which 
has    not    previously    been    used    in    a    rubber    compound,    solid, 
waxy,    hydrocarbons,    suitable     mineral     matter     and     sulphur, 
properly  and  thoroughly   vulcanized.     Before   being  mixed   with 
the   other  Ingredients,    the   rubber   shall   be   thoroughly   washed 
and    dried. 

7.  The  insulation  must  be  homogeneous  in  character,  tough, 
elastic,    adhering   strongly    to,     and     be     placed    concentrically 
around  the  wire. 

Taping,   Filling  and  Braiding. 

8.  The  core  of  the  cable  must  be  made  cylindrical  in  form 
and   properly   laid   up   with   one  wire   in  each   layer  taped  for 
a  tracer.     Cables  of  more  than  three   (3)    and  less  than  seven 
(7)    conductors  shall   be  made  up   with  a  jute  or  sisal   center. 
Each    layer   of  core   must   have   a   spiral  lay,   each   consecutive 
layer   being   spiralled    in   reverse   direction   from   the   preceding 
one.      All    Interstices    between    insulated    conductors    must    be 
thoroughly    filled   with   dry   jute   to    make    round,    and   covered 
with    a    layer   of   rubber   Insulating   tape    overlapping  for   one- 
third    (1-3)     its    width.      The    tape    shall    be    of    closely-woven 
cotton,    filled    with    rubber    insulating    compound    and    laid    to 
make    a    smooth    surface. 

9.  A    bedding    of    jute,    not    less    than    one-sixteenth    (1-16) 
inch   thick   and  saturated  with  tar,   shall  be  wrapped  over  the 
taped   core.      A   layer   of   tape,  overlapping  one- third    (1-3)    Its 
width,   shall   be  laid  on  over  the  jute  in   reverse  order  to  the 
winding   of   the   jute,   and   over   this   shall   be   placed   one    (1) 
layer  of  closely-woven  cotton  braiding  at  least  one-thirty-second 
(1-32)    inch  thick,  saturated  with  a  black,  insulating  weather- 
proof   compound   that   shall    be   neither  injuriously   affected  by 
nor  have  an  injurious  effect  on  the  braid  at  a  temperature  of 
200    degrees    Fahrenheit. 

Acceptance. 

10.  The    product    of    those    concerns    only    wMl    be    accepted 
who    have    satisfied    the    purchaser    that    the    requirements    of 
this    specification   will    be   complied  with.      The    decision    as   to 
the   quality  of   the  cable  furnished   and   the  acceptance  of  the 
same  shall  be  made  by  the  purchaser. 

Tests. 

11.  The    manufacturer    shall    provide,    at    his    factory,    ap- 
paratus   and    other    facilities    needed    for    making    the    required 
physical    and    electrical    tests.       The    manufacturer    shall    give 
free   access    to    the    place   of    manufacture   and   opportunity    for 
inspecting    and    testing   the   product    at    all    stages   of   manufac- 
ture   to    show    that   the    required    amount  and    quality    of   Para 
rubber   and   other   ingredients  are   being  used   in  the   compound. 

12.  Tests  shall  be  made  from  samples  taken  from  any  part 
of  any  coil  of  wire  and  shall  also   be  made  upon  the  finished 
product    before    and,    if    desired,    immediately    after    being    de- 
livered.     If  the   requirements   of   this   specification   are   not  met 
the   cable   will    be   rejected. 

13.  At    the    option    of   the    purchaser,   the    wire,    after    being 
tested,    shall    not    be    made    into    a    cable    until    an    analysis    of 
a    sample    has    been    made    by    a    chemist    chosen    by    the    pur- 
chaser,   and    the    results    of    such    analysis    as    interpreted    by 
the    purchaser     shall    be    sufficient    ground   for    rejection    should 
the  wire  or  insulation  not  conform  to  the  requirements  of  this 
specification. 

Physical   Test  of  Copper  Conductors. 

14.  Each    solid    conductor     must     stand     an     elongation     of 
twenty-five    (25)     per    cent    of    its    length    in    ten    (10)    inches 
before    breaking.       It    must    be    capable    of    being    wrapped    six 
(6)      times     about     its     diameter     without     showing     signs     of 
breakage. 

Ciiiitluc-tirity   Test  of  Copper. 

15.  The   conductivity  of  the  copper  shall  be  determined  by 
measuring    the    resistance    of   a  length    of   wire   and    comparing 
with   Matthiessen's   standard  of  copper  resistance. 

Test  of  Tinninr/. 

16.  Samples   of    wire   shall    be   thoroughly    cleaned   with    al- 
cohol   and    immersed    in    hydrochloric    acid    of    specific    gravity 
1.088    for    one    minute.      They    shall    then    be    rinsed    in    clear 
water    and    immersed    in    a    solution    of     sodium     sulphide     of 
specific    gravity    1.142    for  thirty-two    (32)    seconds    and    again 
washed.      This    operation    shall    be    repeated    three    (3)    times, 
and  if  the  sample  does  not  become  clearly  blackened  after  the 
fourth  immersion  the  tinning  shall  be  regarded  as  satisfactory. 


514 


ACCESSORIES. 


17.  The   sodium    sulphide    solution    must    contain    an    excess 
of    sulphur   and    should    have   sufficient   strength   to   thoroughly 
blacken    a    piece    of    clean    untinned    copper   wire    in    five    (5) 
seconds. 

Physical  Tests  of  Rubber  Insulation. 

18.  A   sample   of   vulcanized   rubber  insulation  not   less  than 
four    (4)    inches    in    length    shall    have   marks    placed    upon    it 
two   (2)    inches   apart.     The  samples  shall  be  stretched  at  the 
rate    of    three     (3)     inches    per    minute    until    the    marks    are 
six    (6)    inches    apart    and    then    at    once    released.      One    (1) 
minute    after    such    release    the   marks    shall    not    be   over    two 
and    seven-sixteenths     (^    7-16)     inches    apart.      Samples    shall 
then  be   stretched   until    the   marks   are   nine    (9)    inches   apart 
before  breaking. 

19.  The  tensile  strength  of  the  rubber  insulation,  as  shown 
by    tests    made    on    a   carefully   prepared    sample,    shall   be   not 
less  than  one  thousand    (1,000)    pounds  per  square  iAch.     The 
sample,  for  five   (5)    minutes  before  and  as  near  as  practicable 
during  the  test,   shall   be  maintained  at  a  temperature   of  sev- 
enty   (70)    degrees  Fahrenheit. 

20.  The  specific  gravity   of  the   rubber  insulation  shall   not 
be  less  than  1.75. 

Chemical   Tests   of   Rubber  Insulation. 

21.  The    insulation    shall    show    on    analysis    not    less    than 
thirty    (30)    nor  more  than  thirty-three    (33)    per  cent  of  pure 
Upriver,   fine,  dry  Para   rubber,   of  best  quality  ;  nor  more  than 
four    (4)    per   cent   of  solid,  waxy   hydrocarbons,   consisting   of 
refined    paraffin    or    pure    ozokerite ;    not    more    than    0.7    per 
cent   of  free   sulphur;    not  more   than    2.5    per   cent   total   sul- 
phur, freedom    from   all   foreign   matter,   and   the   mineral   mat- 
ter shall   be   such   as   will   not   have  a   deleterious   effect   on  the 
insulation. 

Electrical   Tests   of  Rubber  Insulation. 

22.  The    thickness    of    the    rubber    insulation    around    each 
conductor    (measured  at   the   thinnest   point),   the   minimum   in- 
sulation   resistance    in    megohms    per    mile    when    corrected    to 
the    standard    temperature    of    60    degrees    Fahrenheit    and    the 
dielectric    strength    shall    conform     to     the     following     require- 
ments : 


B.  &  S. 
Gauge. 

4 

6 

8 

9 

10 
12 
14 
16 


Thickness 

of 

Insulation. 
3-32  inch 
5-64      " 
5-64      " 
5-64     " 
1-16     " 
1-16      " 
1-16     " 
3-64      " 


Insulation 
Resistance 
Megohms 
Per  Mile. 

1100 

1300 

1600 

1500 

1400 

1600 

1900 

1900 


Test  Voltage 

Alternating 

Current- 

9000 

7000 

7000 

7000 

4000 

4000 

4000 

2000 


23.  The   test    for    insulation    resistance    must   be    made   upon 
all     wire     after     at     least     twelve    (12)     hours'    submersion    in 
water,  and  while  still  immersed  results  be  corrected  to  a  water 
temperature    of    sixty     (60)    degrees    Fahrenheit.      Tests    must 
be  made  with   the  wire   in   coiis,   suitable  for  examination  and 
before    the   application   of   tape    or    other   covering   with   a   well- 
insulated    battery    and    galvanometer,    with    not    less    than    one 
hundred    (100)    volts,  and  readings  must  be  taken  after  one   (1) 
minute's    electrification.     The    test   voltage   must   be  applied   to 
the   completed   length   of   wire   before    the   insulation    test  for   a 
period    of  five    (5)    minutes,    using   alternating    current    from   a 
generator  and   transformer  of   ample  capacity. 

24.  The    cable,    when    made    up   after   assembling   and   braid- 
ing,   shall    have    the    test    voltage    required    for    separate    con- 
ductors,   applied    between    conductors    for    five     (5)    minutes    to 
each  conductor. 

25.  The    insulation    resistance    of    each    conductor    shall    be 
measured   after  test  voltage  has  been  applied  to  the  completed 
cable    and    the    resistance   found    shall    be    not    less   than    that 
specified  for  separate  conductors. 

Inspection. 

26.  The   manufacturer  shall    notify    the  purchaser   when   the 
manufacture   of   the   wire   and   cable   is  to   begin,    in   order   that 
inspection  may  be  arranged  for. 

Reels. 

27.  Each    cable    shall    be    placed    on    a    separate    reel    hold- 
ing  the    full    length    of    cable.      Both    ends    of    cable    must    be 
accessible   for  testing,    but   be   covered    and   protected    from    in- 
jury.     The   flanges   of   the   reel   shall   be   large   enough   to   pro- 
tect   the    cable    in    handling   and    rolling.      The    reels    will    be- 
come  the   property   of  the   purchaser,  but   must   be   taken   back 
by    the   manufacturer    upon    the    reqiiest   of    the    purchaser. 
Marking. 

28.  Each    reel    shall    have    the    weight,    length,    number    of 
conductors  in  cable,  the  name  of  maker  and  purchaser's  order 


or  inspection  number  plainly  and  indelibly  marked  on  a   strong 
tag  securely  fastened  to  the  cable,  and  also  stenciled  on  the  out- 
side of  the  reel. 
Notification. 

29.  The  completed  cable  is  not  to  be  shipped  from  place 
of  manufacture  until  permission  in  writing  has  been  received 
from  the  purchaser.  Should  the  cable,  on  arrival  at  destina- 
tion, be  found  defective  and  not  up  to  the  specification  re- 
quirements, it  will  be  returned  to  the  manufacturer,  who  must 
pay  all  freight  charges. 

REVISED     SPECIFICATION      FOR     GALVANIZED     E.      B.      B.      IRON     BOND 
WIRES. 

General    Di'fti-ription. 

1.  The    intention    of    this    specification    is    to    provide    for 
the    furnishing    of    No.    8    B.    W.    G.    galvanized    E.    B.    B.    iron 
wires    for    bonding    rail    joints    of    steam    railroads    where    elec- 
tric track   circuits  are   to  be   used. 

Conductor. 

2.  The    wire  must   be   cylindrical   in   form,   free   from  scales, 
Haws,    inequalities,    splits    and    all    imperfections.       The     wires 
shall   be  cut  and  straightened  to  the  length  specified  on  order. 
The  ends   shall   be  sheared   cut  and  free  from  burrs. 

3.  The    galvanizing    shall    consist    of   a    continuous    coating 
of    pure    /dnc    of    uniform    thickness    and    so    applied    that    it 
adheres  firmly  to  the  iron  and  presents  a   smooth  surface. 
Properties. 

4.  The  mechanical   and   electrical   properties   of  the   finished 
wire   must    be    in    accord    with    the    following   requirements : 

Breaking        Per  Cent         Resistance 

B.  W.  Gauge    Diameter    Resistance,    Elongation     Ohms  per  Mile 
in  Mils.         Pounds,    in  10  Inches,    at  68  Deg.  F. 


165 


975 


15 


12.05 


The    wire    shall    not    vary    more    than    three    (3)    mils    from 
the  normal  diameter. 
Test  of  Galvanizing. 

5.  A   sufficient  number  of  samples  shall   be  taken   from   the 
wire  submitted  for  inspection  and  shall  be  tested,  these  pieces 
being  not   less   than  eight    (8)    inches  long  and  not  more  than 
seven    (7)    pieces   of   wire    shall    be    immersed   in    the   specified 
quantity   of  solution. 

6.  The    samples    shall    be    cleaned    before    being   tested,    first 
with    carbona,    benx.ine    or    turpentine    and    cotton    waste,    and 
then    thoroughly    rinsed    in    clean    water    and    wiped    dry    with 
clean   cotton  waste.     The   samples   shall   be   cleaned   and   dried 
before    being    immersed    In    the    solution.      The    samples,    when 
placed    in   the   solution,   shall   be   well    separated  to   permit   the 
solution    to    act    uniformly    on    all    immersed    portions    of    the 
samples. 

7.  The    samples    shall    be    tested    In    a    neutral    solution    of 
commercial   copper   sulphate   having  a  specific  gravity   of  1.186 
at    a    temperature    of    65    degrees    F.      The    solution    shall    be 
neutralized  by   the  addition  of  excess  of  chemically  pure  cupric 
oxide    (Cu   O),    which   will    collect    in   tht   bottom   of   the    con- 
taining   vessel.      The    solution    shall    be    filtered    before    being 
used.      Not   less   than   four    (4)    ounces   of   fresh   solution   shall 
be  used  for  each  test  of  seven    (7)    wires.     The  solution  must 
be    maintained    at    a    temperature    between    62    and    68    degrees 
Fahrenheit    during    the    test.      The    samples    shall    be    immersed 
in  the  solution  to  a  depth  of  four  (4)  inches. 

8.  The   samples   shall   be   immersed   in   the  solution  for  one 
minute,   shall  then  be  washed  in  clean  water  having  a  tempera- 
ture  of  between    62   and    68    degrees   Fahrenheit  and   be   wiped 
dry    with    clean    cotton    waste.      This    operation    shall    be    per- 
formed  four    (4)    times. 

9.  If    there    is    a    bright     metallic     copper     deposit     on     the 
samples   after    the    fourth    immersion,    the    wire,    represented   by 
the   samples,    shall    be    rejected,    but    copper   deposited    on    zinc 
or   within    one    (1)    inch    of   the   end  of  the    sample   shall   not 
be   considered   as  cause  for  rejection. 

10.  In  case   of   a   failure  of  one    (1)    wire  in   the  group  of 
seven     (7)     being    tested    together,    or    if    there    is    reasonable 
doubt    as    to    the    copper    deposit,    two    (2)    check    tests    shall 
be    made    of    samples    from    the    same    bundle,    but    unless    the 
two   (2)   check  tests  are  satisfactory,  the  wire  shall  be  rejected. 
Inspection    and    Testa. 

11.  The   purchaser    Is   to    have   the   right   to   make   such   in- 
spection and  tests  as  he   may  desire  of  the  wire  at  any  stage 
of  the   manufacture. 

12.  The    manufacturer    must    provide,    at    the    mill,    all    ap- 
paratus   and    labor    for    making    the    required    tests    under    the 
supervision  of  the  purchaser. 


ACCESSORIES. 


13.  Tests   shall    be   made   at   the   mill,   ou   the  wire  before   it 
is    cut    into    lengths,    or    on    samples    submitted    by    the    manu 
facturer,    aud   may   also   be   made  on   the   wire   upon   its   arrival 
at    destination. 

14.  If,   upon  arrival   at   destination,    the   wires   do   not   meet 
the    requirements    of    this    specification,    they    will    be    rejected 
and    returned    to    the   manufacturer,    who    shall    pay    all    freight 
charges. 

I'tifkiiig   for  Shipment. 

15.  The  wire  shall  be  put  in  bundles  of  one  hundred    (100) 
or    three    hundred    (300),    as    ordered,    well    burlapped    at    ends 
and  securely   fastened   in    not  less   than   three    (3)    places. 
Tagging. 

16.  A   tag  shall  be  securely  fastened   to  each  bundle,  having 
plainly    and    indelibly    marked    thereon    the     number     of     and 
length  of  the  wires,  the  purchaser's  order  and  inspection  num 
her  and  the  proper  shipping  address. 

REVISED     SPECIFICATION     FOR    DOUBLE-BRAIDED,     WEATHERPROOF, 
GALVANIZED    B.    B.     IRON     LINE     WIRE. 

General  Description. 

1.  The   intention   of   this   specification   is   to   provide   for  the 
furnishing  of  galvanized  B.   B.   iron  line  wire,   which  is  covered 
with    a   double    thickness    of   weather-proof   braiding. 
Conductor. 

2.  The   wire   must   be   cylindrical    in    form,  free   from   scales. 
flaws,    inequalities,     splits    and    all     imperfections.       Each    coll 
must   contain   no   weld,   joint   or   splice. 

3.  The    galvanizing    shall    consist    of    a    continuous    coating 
of    pure    zinc    of    uniform    thickness    and    so    applied    that    it 
adheres    firmly   to    the    iron    and    presents   a  smooth   surface. 
Properties. 

4.  The   mechanical    and   electrical   properties   of   tue   finished 
wire    must   be    in    accord    with    the    following    requirements: 


Breaking        Ter  Cent 


Resistance 


H.   W.   Gauge     Diameter  Strength,     Elongation  Ohms  per  Mile 

in   Mils.  Pounds,    in  10  Inches,  at  68  Deg.  F. 

6                        203  1,652               15                        9.49 

8                        105  1,092               15                      14.36 

10                        134  722               12                      21.71 

12                       109  476              12                     32.94 

Test  of   Galvanizing. 

5.  A   sufficient   number  of  samples   shall    be   taken   from   the 
wire   submitted  for  inspection  and   shall   be  tested,  these   pieces 
being   not   less  than  eight    (8)    inches   long   and   not   more   than 
seven    (7)    pieces    of    wire    shall    be    immersed    in    the    specified 
quantity   of  solution. 

6.  The    samples    shall    be    cleaned    before    being    tested,    first 
with  carbona,  benzine  or  turpentine  and  cotton  waste,  and  then 
thoroughly    rinsed    in    clean    water    and    wiped    dry    with    clean 
cotton   waste.     The   samples   shall  be  cleaned  and  dried  before 
being  immersed  in   the   solution.      The  samples,  when   placed   In 
the    solution,    shall    be    well    separated    to    permit    the    solution 
to    act   uniformly   on    all    immersed    portions    of    the   samples. 

7.  The    samples    shall    be    tested    in    a    neutral    solution    of 
commercial   copper   sulphate   having  a   specific   gravity  of   1.1 8fi 
at  a  temperature  of  65  degrees  Fahrenheit.     The  solution  shall 
be    neutralized   by    the    addition    of    excess    of    chemically    pure 
cupric   oxide    (Cu   O),    which   will   collect   in   the   bottom   of  the 
containing   vessel.      The   solution    shall   be   filtered   before   being 
used.      Not   less   than   four    (4)    ounces   of   fresh    solution    shall 
he   used   for  each   test  of   seven    (7)    wires.     This   solution  must 
be    maintained    at    a    temperature    between    62    and    68    degrees 
Fahrenheit    during    the    test.      The    samples    shall    be    immersed 
in   the  solution   to    a    depth    of   four    (4)    inches. 

8.  The    samples   shall    be    immersed   in    the   solution    for   one 
(1)     minute,    shall    then    be    washed    in    clean    water    having    a 
temperature   of  between    62   and   68   degrees   Fahrenheit,  and  be 
wiped    dry    with    cotton    waste.      This    operation    shall    be    per- 
formed four    (4)    times. 

9.  If  there  is  a  bright  metallic  copper  deposit  on  the  sam- 
ples  after   the   fourth    immersion,    the   wire,    represented  by   the 
samples,     shall     be     rejected,    but    copper    deposited    on    zinc    or 
within   one    (1)    inch    of   the    end    of    the   sample    shall    not    be 
considered   as   cause  for   rejection. 

10.  In    case    of    a  failure  of  one   (1)   wire  in  the  group  of 
seven     (7)     being    tested    together,    or    if    there    is    reasonable 
doubt   as    to    the    copper   deposit,    two    (2)    check  tests   shall    be 
made    of   samples   from   the  same   coil,   but    unless   the   two    (2) 
(  heck  tests  are  satisfactory  the  wire  shall  be  rejected. 
Covering, 

11.  The    conductor    shall    be    covered   with    two    (2)    closely- 
woven  braids   of    cotton,   each   of  which   shall   not  be   less  than 
one-thirty-second    (1-32)    inch  in  thickness.     This  braiding  shall 
be  thoroughly  saturated  with  a  permanent  weatherproofing  com 


pound,    which    shall    l.e   applied,  in   sufficient    quantity   to   fill   all 
interstices   and  form   a  continuous  coating  over  the  covering. 

12.  The  temperature   of   the   saturating  compound   shall   not 
he   more   than    300    degrees   Fahrenheit,    or   such   as  will   soften 
the    wire    more    than    is    allowable    with    the    elongation    re- 
quired.     The   wire   must   remain    in   the   compound   long   enough 
to   drive  out  all   moisture   in  the   covering  and  must  be  closely 
stripped    so    that   there    shall    not    be   any    excess   of    compound 
beyond  what   Is  absorbed  by   the  cotton  and   the   filling  of  the 
interstices  of   the   same,    leaving  a  good,  smooth  surface. 

13.  The    compound    shall    be    insoluble    in    water,    shall    not 
m^lt   when   the  finished  wire  is  subjected  to  a   temperature  of 
one    hundred    and    twenty-five     (125)     degrees    Fahrenheit    and 
shall   not  crack  when  the  finished  wire  is  subjected  to  a  tem- 
perature   of   ten    (10)    degrees   below    zero    Fahrenheit. 

14.  The    qualities    of    the   compound    used    and    the    method 
of    application    shall    be    such    as    not    to    injure    the    braidea 
covering  of   the  wire. 

15.  The   melting  and   freezing   tests  of   the  compound   shall 
be   made   as   follows : 

Short  pieces  of  wire  shall  be  placed  on  a  piece  of  clean 
white  glazed  paper  in  a  chamber  which  has  been  heated  to 
125  degrees  Fahrenheit,  this  temperature  to  be  maintained 
for  half  an  hour.  The  wire  shall  be  rejected  if  the  com- 
pound becomes  sufficiently  fluid  to  be  transferred  to  the  paper 
on  which  the  wire  was  placed  in  sufficient  amount  to  form 
a  ridge  perceptible  to  the  fingers,  or  in  case  the  compound 
is  absorbed  by  the  paper  as  indicated  by  a  greasy  or  oily 
spot. 

16.  The  finished  wire   shall  be   immersed   in  a  freezing  mix- 
ture   which    shall    show    a    temperature    of    ten     (10)    degrees 
below   zero    Fahrenheit    for    one-half    (%)    hour,    and    if,    upon 
removal,    the    compound    so    contracts     (without    bending    sam- 
ple)   as    to    produce    cracks    in    its    surface,    the    wire    shall    be 
rejected. 

Inspection  and   Tests. 

17.  The   purchaser   is  to   have   the   right   to   make  such   in- 
spection   and    tests    as    he    may    desire    of    the    materials    and 
of  the  wire  at  any  stage  of  the  manufacture. 

18.  The    manufacturer    must    provide    at    the    mill    all    ap- 
paratus   and    labor    for    making   the    required    tests    under   the 
supervision    of   the   purchaser. 

19.  Tests    shall    be    made    at   the    mill    or    on   samples    sub- 
mitted   by    the    manufacturer,    and    may    also    be    made    on    the 
wire  upon  its  arrival  at  destination.     The  wire  may  be  inspected 
before  and  after  it  has  been  covered. 

20.  If,    upon     arrival    at    destination,     the    wire    does     not 
meet    the    requirements    of    this    specification,    it    will    be    re- 
jected  and    returned    to    the    manufacturer,    who    shall    pay    al! 
freight   charges. 

Packing    for    Shipment. 

21.  The   wire   shall    be    furnished   in    coils    of    not    less   than 
the   following    lengths  : 

0  to  4,  inclusive,  one-fourth  mile. 
6  to  8,  inclusive,  one-third  mile. 
9  to  12,  inclusive,  one-half  mile. 

22.  The    diameter    of  the   eye   of   the    coil   shall    be   not   less 
than    twenty     (20)     inches,    nor    more    than    twenty-two     (22) 
inches. 

23.  Each  coil  shall  be  securely  bound  with  a  layer  of  heavy 
wrapping  paper   and  with  an   outside  wrapping  of  burlap,   with 
each    turn    of    burlap    overlapping    the    other    one-half    (%)    its 
width. 

21.  Each  coil  shall  have  the  weight,  length  and  size  of 
wire,  the  name  of  the  maker,  the  purchaser's  «.rder  and  in- 
spection number  and  the  proper  shipping  address  plainly  and 
indelibly  marked  on  two  (2)  strong  tags.  One  of  these  tags 
shall  be  attached  to  the  coil  inside  the  burlap  and  the  other 
shall  he  attached  to  the  coil  outside  the  burlap. 

SPECIFICATION     FOR     RUBBER-I  NSULATED,     LEAD-COVERED,     ARMORED 
SUBMARINE    CABLE    FOR    660    OR    LOWER    VOLTAGE    SERVICE. 

General. 

1.  The    cable    bought    under    this    specification    will    be    used 
under   water   for current    at 

volts,    aud   shall   be 

feet   in    length. 

2.  All    workmanship    and    material    shall    be    first  class    and 
the   best   of   their   respective   kinds,   and  shall   be   in  full   accord 
with    the    best    modern    electrical    and    mechanical    engineering 
practice. 

Form   of   Cable. 

3.  The   cable  shall    consist   of 

conductors   insulated   with   rubber  and  stranded   into  cable  with 
jute   laterals   to   make   round.      The   whole   to  be   taped   and  the 


ACCESSORIES. 


core    thus    formed    shall    Lave    Irad    shout h    with    jute    covering 
over  lead,    with   armor   and  a   covering  of  jute   over   the   armor 
as    herein    specified. 
Conductors. 

4.     Conductors    shall    be    of    the    following    sixes    and    num- 
bers : 

Approximate 
Nearest  Size 

Number   of     B.  &  S.  Gauge 
Conductors.  Each 

Conductor. 


Number   of      Size   of     Actual  C.  M. 

Strands.         Strands,    of  Conductor. 


5.  Conductors   must   be   of   soft-drawn,   annealed  copper  wire 
having   a   conductivity   of  not    less   than  ninety-eight    (98)    per- 
cent   of    that    of    pure    copper,    Matthiessen's    standard.       Each 
wire   forming  a   conductor   must   be    continuous,    without    weld, 
splice  or  joint  throughout  its  length,  must  be  uniform  in  cross 
section,    free   from    flaws,    scales    and   other    imperfections    and 
provided   with   a  heavy  uniform  coating  of  tin. 

Rubber  Insulation. 

6.  The    rubber    insulation    shall    be    made    exclusively    from 
pure  Upriver,  fine,  dry  Para  rubber,  of  best  quality,  which   has 
not   previously   been   used    in    a   rubber   compound,   solid,    waxy 
hydrocarbons,    suitable    mineral    matter    and    sulphur,    properly 
and     thoroughly    vulcanized.       Before     being     mixed    with     the 
other   ingredients   the   rubber    shall   be   thoroughly  washed    and 
dried. 

7.  The  insulation  must  be  homogeneous  in  character,  tough, 
elastic,    adhering   strongly     to     and     be     placed     concentrically 
around   the   wire. 

Taping  and  Filling.        * 

8.  The    core    of    the    cable    must    be    made    cylindrical     in 
form  and  properly  laid  up   with  one  wire  in  each  layer  taped 
for   a   tracer.      Cables   of  more   than   three    (3)    and   less   than 
seven    (7)    conductors   shall   be   made   up   with   a   jute   or   sisal 
center.     Each  layer  of  core  must  have  a  spiral  lay,  each    <-<>n 
secutive    layer    being    spiraled    in    reverse    direction    from    tin- 
preceding    one.      All    interstices    between    insulated    conductors 
must    be    thoroughly    iilled    with    dry   jute    to    make    round    and 
covered  with  a  layer  of  rubber  insulating  tape  overlapping  for 
one-third    (1-3)    its   width. 

9.  The    tape    shall    be    of    closely-woven    cotton    filled    with 
rubber   insulating   compound   and   laid   to   make   a    smooth    sur- 
face.     The    jute    is    to    be    well    twisted    and    to    be    appliod 
spirally. 

Sheath. 

10.  A    sheath,    one-eighth     (%)    of    an    inch    in    thickness, 
consisting    of    an    alloy    of    lead    and    tin,    containing    not    lcs< 
than   ninety-eight    (98)    per  cent  pure   lead   and   from   one    (1) 
to  two    (2)    per  cent  tin,  shall   be   applied   over   the  assembled 
and  taped  conductors. 

Armoring  and  Braiding. 

11.  The  sheath  shall  be  protected  by  a  layer  of  asphalt  or 
tarred   jute,    well    twisted    and   applied   spirally   and    having    a 
thickness  of  three-thirty-seconds    (3-32)   of  an  inch.     Over   tin; 
jute    covering    shall    be    placed    a    covering    consisting    of    No. 
4    B.   &   S.   gauge   galvanized   mild  steel   wires   applied    spirally 
and  laid  to  fit  closely,  one  wire  to  the  next. 

12.  Over  the  armoring  a   layer  of  closely-woven  jute  braid- 
ing  shall  be   placed,   at   least   one-sixteenth    (1-16)    inch    thick, 
saturated    with    a    black,     insulating    weatherproof    compound 
that   shall    be   neither   injuriously    affected   by    nor   have   an    in- 
jurious effect  upon  the  braid  at  200  degrees  Fahrenheit. 
Acceptance. 

13.  The   product    of    those    concerns    only    will    be   accepted 
who  have  satisfied  the  purchaser  that  the  requirements  of  this 
specification   will    be    complied   with.      The    decision    as   to    tfie 
quality  of  the  cable  furnished   and  the  acceptance   of  the  same 
shall   be  made  by  the   purchaser. 

Tests. 

14.  The  manufacturer  shall  provide  at  his  factory  apparatus 
and    other    facilities    needed    for    making    the    required    physical 
and   electrical   tests.      The   manufacturer   shall    give   free   access 
to    the    place    of    manufacture    and    opportunity    for    inspecting 
and   testing  the  product  at  all   stages  of  manufacture  to   show 
that    the    required    amount    and    quality    of    Para    rubber    and 
other    ingredients    are    being    used    in   the   compound. 

15.  Tests  shall   be  made  from   samples   taken  from  any   part 
of  any  coil   of  wire  and  shall   also  be  made  upon  the  finishod 
product    before    and,    if    desired,    immediately    after    being    de- 
livered.     If  the   requirements  of   this   specification   are  not   mot 
the  cable  will  be  rejected. 

1C.  At  the  option  of  the  purchaser,  the  wire  after  being 
tested  shall  not  be  made  into  a  cable  until  an  analysis  of 
a  sninple  has  boon  made  by  a  chemist,  chosen  by  the  pur- 


chaser, and  t  hi:  results  of  such  analysis  as  interpreted  by 
the  purchaser,  shall  be  sufficient  ground  for  rejection  should 
the  wire  or  insulation  not  conform  to  the  requirements  of 
this  specification. 

Physical   Test   of   Copper  Conductors. 

17.  Each    solid    conductor    must     stand  an     elongation  of 
twenty-five    (25)    per  cent  of  its  length  in  ten    (10)    inches  be- 
fore   breaking.       It    must    be     capable    of  being    wrapped  six 
(6)     times    about    its     diameter     without  showing     signs  of 
breakage. 

Conductivity  Test  of  Copper. 

18.  The   conductivity  of  the   copper   shall   be  determined   by 
measuring   the    resistance  of   a   length   of  wire   and    comparing 
with    Matthiessen's    standard    of    copper    resistance. 

Test  of   Tinning. 

19.  Samples    of    wire   shall    be    thoroughly    cleaned    with    al- 
cohol   and    immersed    in    hydrochloric    acid    of   specific    gravity 
1.088     for     one     (1)     minute.       They    shall    then    be    rinsed    in 
clear    water    and    immersed    in    a    solution    of    sodium    sulphide 
of    specific    gravity     1.142     for     thirty-two     (32)     seconds    and 
again    washed.      This    operation    shall    be    repeated    three     (3) 
times,    and    if    the    sample    does    not    become    clearly    blackened 
after   the    fourth    immersion    the    tinning    shall    be    regarded    as 
satisfactory. 

20.  The    sodium    sulphide    solution   must    contain    an    excess 
of   sulphur    and    should   have    sufficient    strength    to    thoroughly 
blacken    a    piece    of    clean    untinned    copper    wire    in    five    (5) 
seconds. 

I'lnjxical  Tests  of  Rubber  Insulation. 

21.  A  sample  of  vulcanized  rubber  insulation  not  less  than 
four    (4)    inches    in    length   shall    have    marks    placed    upon    it 
two    (2)     inches    apart.      The    samples    shall    be    stretched    at 
the    rate    of    three     (3)     inches    per    minute    until    the    marks 
are  six   (6)    inches  apart  and  then  at  once  released.     One   (1) 
minute    after    such    release   the    marks    shall    not    be    over    two 
and    seven-sixteenths     (2    7-16)     inches    apart.      Samples    shall 
then    be    stretched    until    the    marks    are  nine    (9)    inches   apart 
before   breaking. 

22.  The   tensile   strength   of  the  rubber  insulation   as  shown 
by    tests   made    on    a    carefully    prepared    sample    shall    be    not 
less    than    one    thousand     (1,000)      pounds     per     square     inch. 
The    sample,    for    five    (5)     minutes    before    and    as    near    as 
practicable  during  the  test,  shall  be  maintained  at  a  tempera- 
ture of  seventy    (70)    degrees  Fahrenheit. 

23.  The   specific    gravity   of  the   rubber   insulation    shall    not 
lie   loss   than   1.75. 

I'lii'inicdl    Tests   of  Rubber  Insulation. 

21.  The  insulation  shall  show  on  analysis  not  less  than 
thirty  (30)  nor  more  than  thirty-three  (33)  per  cent  of  pinv 
Upriver,  fine,  dry  I'ara  rubber,  of  best  quality;  not  more 
than  four  (4)  per  cent  of  solid,  waxy  hydrocarbons,  con- 
sisting of  refined  paraffin  or  pure  ozokerite ;  not  more  thafi 
0.7  per  cent  of  free  sulphur;  not  more  than  2.5  per  cent 
total  sulphur,  freedom  from  all  foreign  matter  and  the  mineral 
matter  shall  be  such  as  will  not  have  a  deleterious  effect  on 
the  insulation. 
Electrical  Tests  of  Rubber  Insulation. 

25.  The  thickness  of  the  rubber  insulation  around  each 
conductor  (measured  at  the  thinnest  point),  the  minimum  in- 
sulation resistance  in  megohms  per  mile  when  corrected  to 
the  standard  temperature  of  60  degrees  Fahrenheit  and  the 
dielectric  strength  shall  conform  to  the  following  require- 
ments : 


B.  &  S. 

<:aui;e. 
0 
1 
2 

4 

6 

8 

9 

10 
12 
14 
16 


Thickness 

of 

Insulation. 
1-  8  inch 
1-  8  " 
1-  8  " 
3-32  " 
3-32  " 
3-32  " 
5-64  " 
5-64  " 
5-64  " 
5-64  " 
1-16  " 


Insulation 
Hesistance 

Test  Voltage 

Megohms 

Alternating 

Per  Mile. 

Current. 

900 

10,000 

1100 

10,000 

1200 

10.000 

1100 

9000 

1300 

9000 

1600 

9000 

1500 

7000 

1600 

7000 

1900 

7000 

2100 

7000 

2100 

4000 

26.  The  test  for  insulation  resistance  must  be  made  upon 
all  wire  after  at  least  twelve  (12)  hours'  submersion  in 
water  and  while  still  immersed  results  be  corrected  to  a  water 
temperature  of  sixty  (60)  degrees  Fahrenheit.  Tests  must  be 
made  with  the  wire  in  coils,  suitable  for  examination  and 
before  the  application  of  tape  or  other  covering  with  a  well- 
insulated  battery  and  galvanometer,  with  not  less  than  one 


ACCESSORIES. 


Si? 


hundred  (100)  volls,  JUKI  readings  must  be  taken  after  one 
minute's  elect  niicatioii.  The  test  voltage  must  be  applied 
io  the  completed  length  of  wire  before  the  insulation  test  for 
a  period  of  live  (5)  minutes,  using  alternating  current  from" 
a  generator  and  transfi.Tmer  of  ample  capacity. 

27.  The  cable  when  made  up  after  assembling  with  lead 
covering  and  armoring  shall  have  the  test  voltage  applied  for 
five  (5)  minules  to  each  conductor,  as  follows: 

-8.  Between  conductors,  apply  the  full  voltage  test  as  re- 
quired for  separate  wires. 

-'9.  Between  each  conductor  and  lead  sheath  apply  a  test 
volia.ue  of  but  60  per  cent  of  that  required  for  separate 
wires. 

30.  The    insulation    resistance    of    each    conductor    shall    be 
measured   after   test   voltage  has  been  applied  to  the  completed 
•  •able    and    the    resistance    found    shall    be    not    less    than    that 
specified   for   separate   conductors. 

Inspection. 

31.  The  manufacturer   shall   notify   the   purchaser   when    the 
manufacture   of   the    wire    and   cable   is   to   begin,   in  order   that 
inspection    may    be    arranged    for. 

Reels, 

32.  Each   cable   shall    be    placed    on   a   separate    reel    holding 
the  full  length  of  cable.     Both  ends  of  cable  must  be  accessible 
for    testing,    but    be    covered    and    protected    from    injury.      The 
rianges   of   the   reel   shall   be   large  enough   to   protect    the   cable 
in    handling   and    rolling.      The    reels    will    become   the    property 
of   the  purchaser,   but  must  be  taken  back  by  the  manufacturer 
upon   the   request   of   the    purchaser. 

Marking. 

33.  Each    reel    shall    have    the    weight,    length,    number    of 
conductors   in   cable,   the  name  of  maker  and   purchaser's   order 
or   inspection  number  plainly  and  indelibly  marked  on  a  strong 
tag    securely    fastened    to    the    cable    and   also    stenciled    on    the 
outside  of  the  reel. 

Notification. 

34.  The    completed    cable    is    not    to    be   shipped    from    place 
of    manufacture    until    permission    in    writing   has   been   received 
from    the    purchaser.      Should    the   cable   on    arrival    at    destina 
tion    be    found    defective    and    not    up    to    the    specification    re- 
quirements, it  will  be  returned  to  the  manufacturer,  who  must 
pay  all  freight  charges. 

SPECIFICATION   FOR  DOUBLE-BRAIDED,   WEATHERPROOF,   HARD-DRAWN, 
COPPER-CLAD,     STEEL     LINE     WIRE. 

(li'iu-ral  Description. 

1.  The  intention  of   this    specification   is   to  provide   for   the 
furnishing    of    copper-clad,    steel    line    wire,    which    is    covered 
with  a  double  thickness  of  weatherproof  braiding. 
Conductor. 

2.  The  wire  shall  be  composed  of  a  steel   core  with   a  cop- 
per   co.'it    permanently    welded    thereto.       The     wire     must     be 
cylindrical   in   form,   free   from  scales,  flaws,    inequalities,   splits 
and   all    imperfections.      Each    coil   must   contain   no  weld,  joint 
or   splice. 

Properties. 

3.  The   mechanical   and   electrical    properties   of  the   finished 
wire    must    be    in    accord    with    the    following    requirements : 


B.  &  S. 

Gauge 

6 

7 

8 

9 

10 


Diameter 
in  Mils. 

162 

.  144 

128 

114 

102 

81 


Breaking 
Strength, 
Pounds. 
1700 
1450 
1150 

950 

760 

490 


Conductivity  Pel- 
Cent  of  Pure  Cop- 
per at  60  Deg.  K. 

35 

35 

35 

35 

35 

35 


4.  The  wire  when   broken   by  twisting,   repeated   bending,   or 
when    heated   to   a    dull    red   and   quenched    in    water   at    32   de- 
grees  Fahrenheit,   shall  show  no  separation   of  the  copper  from 
the   steel. 

5.  Should  the  breaking  weight  of  the  coll  be  less  than  that 
specified,    tests    of    two    (2)    additional    samples   shall    be    made 
from    the    same    coil    and    the    average    of    the    three    (3)     tests 
shall    determine    the    acceptance    or    rejection    of   the   coil. 

<!.      Should  the   conductivity   of   a  sample   of   a   coil    be   lower 
than    that    specified,    pieces    may   be    cut   from    each    end    until 
.samples   are   obtained   having  the   required  conductivity. 
Covering. 

7.  The  conductor  shall  be  covered  with  two  (2)  closely- 
woven  braids  of  cotton,  each  of  which  shall  not  be  less  than 
one-thirty-second  (1-32)  inch  in  thickness.  This  braiding 
shall  be  thoroughly  saturated  with  a  permanent  weather- 
proofing  compound,  which  shall  be  applied  in  sufficient  quantity 
to  fill  all  interstices  and  form  a  continuous  coating  over  the 
covering. 


s  The  temperature  of  the-  saturating  compound  shall  nut 
I.e  more  than  300  degrees  Fahrenheit  or  such  as  will  soften 
the  wire  more  than  is  allowable  with  the  elongation  required. 
The  wire  must  remain  in  the  compound  long  enough  to  drive 
out  all  moisture  in  the  covering,  and  must  be  closely  stripped, 
so  that  there,  shall  not  be  any  excess  of  compound  beyond 
what  is  absorbed  by  the  cotton  and  the  filling  of  the  interstices 
of  the  same,  leaving  a  good,  smooth  sun 

9.  The  compound  shall  be  insoluble  in  water,  shall  not  melt 
when   the    finished    wire    is   subjected    to    a    temperature   of   one 
hundred    and    twenty-five    (125)    degrees    Fahrenheit    and    shall 
not   crack   when   the   finished    wire   is   subjected   to   a  tempera 
ture  of  ten   (10)  degrees  below  Fahrenheit. 

10.  The    qualities    of    the    compound    used    and    the    method 
of  application  shall  be  such  as  not  to  injure  the  braided  cover- 
ing of  the  wire.        » 

11.  The   melting  and   freezing  tests  of   the   compound   sha'l 
be  made  as  follows  : 

Short  pieces  of  wire  shall  be  placed  on  a  piece  of  clean 
white  glazed  paper  in  a  chamber  which  has  been  heated  to  125 
degrees  Fahrenheit,  this  temperature  to  be  maintained  for 
half  an  hour.  The  wire  shall  be  rejected  if  the  compound 
becomes  sufficiently  fluid  to  be  transferred  to  the  paper  on 
which  the  wire  was  placed,  in  sufficient  amount  to  form  a 
ridge  perceptible  to  the  fingers,  or  in  case  the  compound  is 
absorbed  by  the  paper  as  indicated  by  a  greasy  or  oil  spot. 

12.  The    finished    wire    shall    be     immersed     in     a     freezing 
mixture    which    shall   show  a    temperature   of   ten    (10)    degrees 
below    zero    Fahrenheit    for    one-half    ( J/2 )    hour,   and    if,    upon 
removal,  the  compound  so  contracts   (without  bending  sample  > 
as    to    produce    cracks    In    the   surface,    the    wire    shall    be    re- 
jected. 

Inspection  and  Tests. 

13.  The   purchaser   is  to    have   the   right   to   make   such   in- 
spection  and  tests   as   he   may  desire  of   the   materials  and  of 
the  wire  at  any  stage  of  the  manufacture. 

14.  The    manufacturer    must    provide    at    the    mill    all    ap- 
paratus   and    labor    for    making    the    required    tests    under    tin- 
supervision    of    the   purchaser. 

15.  Tests    shall    be    made    at    the    mill    or    on    samples    sub 
mitted    by   the    manufacturer,    and    may   also   be   made   on    the 
wire    upon    its    arrival    at    destination.      The    wire    may    be    in- 
spected  before    and    after    it   has   been    covered. 

16.  If,   upon   arrival   at   destination,  the   wire   does  not   meet 
the   requirements   of   this   specification,   it  will  be  rejected  and 
returned  to  the  manufacturer,  who  shall  pay  all  freight  charges. 
Packing   for  Shipment. 

17.  The   wire   shall    be   furnished   in    coils    of   not    less   than 
the   following   lengths  : 

0  to    4,   inclusive,  one-fourth    mile. 
6  to    8,  inclusive,  one-third  mile. 
9   to  12,  inclusive,   one-half  mile. 

18.  The   diameter  of  the   eye  of   the   coil   shall   be   not  less 
than    twenty     (20)     inches,    nor    more    than    twenty-two     (22) 
inches. 

19.  Each  coil  shall  be  securely  bound  with  a  layer  of  heavy 
wrapping  paper  and  with  an  outside  wrapping  of  burlap,  with 
each    turn   of   burlap    overlapping   the   other   one-half    (%)    Its 
width. 

20.  Each    coll    shall    have    the   weight,    length    and    size    of 
wire,    name    of    maker,    the    purchaser's    order    and    inspection 
number,    and    the    pioper    shipping    address    plainly    and    indeli- 
bly   marked    on    two    (2)    strong   tags.      One   of    these   shall    be 
attached  to  the  coil   inside  the  burlap  and  the  other  shall   be 
attached    to    the   coil    outside    the    burlap. 

SPECIFICATIONS   FOR    WOOD    TRUNKING. 

General. 

1.  The     material     required     under     these     specifications     Is 
wooden    trunking    to    be    used   for    the    protection   of   rubber    in- 
sulated wires   in   railroad  signaling. 

2.  It    must   be   furnished   either   surfaced    four    (4)    sides    ;>:• 
rough  sawed,   as  specified.      When   furnished   surfaced   four    (4> 
sides,    it    must   conform    to    dimensions    shown     on     R.     S.     A. 

drawing    When    furnished    rough    sawed,    the 

outside    dimensions    as    shown    on    the    drawing    will    be    con- 
sidered   a    minimum,    and    a    variation    of    not    more    than    one- 
fourth     ( % )     Inch    will    be    allowed    for    maximum ;    while    for 
the    groove,    the    dimensions    as    shown    on    the    drawing    must 
be    adhered    to    for    the    minimum    and    an    increase    in    size    of 
one-eighth    (%)    inch  either  way   will  be   allowed  as   maximum. 

3.  Trunking   shall   be  graded   0:1    finished  or  better  side,   but 
the   other  side   shall    not   be    more    than   one   grade   below. 

4.  Lumber     shall     be    manufactured     and     shipped     uniform 
and    even    in    lengths,    approximately    sixteen      (16)     feet     long. 
No  piece  shall    be   less   than   fourteen    (14)    feet  nor  more   than 
eighteen    (18)    feet    long. 

5.  Knot  holes  will  not  be  permitted. 


ACCESSORIES. 


6.     Shake    will    not    be    permitted. 
7.     Wane    shall    not    extend    more    than    one-half     (  y2  )     Inch 
across    any    face,    nor    more    than   one-quarter    (  J/4  )    the    length 
of  any  piece. 

WEATHERPROOF  WIRE,'. 
Approximate  Weights. 
STRANDED. 

8.     Sides    of    groove    may    be    sawed,    but    bottom    of    groove 
must  be  knife  cut. 

Capacity. 
Circular 
Mills. 

Double  Braid. 
Lbs.  per      Lbs.  per 
1000  ft.             mile. 

Triple  Braid. 
Lbs.  per     Lbs.  per 
1000  ft.            mile. 

9.     May    have   one  split  not   to   exceed    in   length   the   width 

2,000,000 

6,690 

35,323 

7,008 

37,000 

of  the  piece. 

1,750,000 

5,894 

31,119 

6,193 

32,700 

Cypress    Trunking. 

1,500,000 

5,098 

26,915 

5,380 

28,400 

10.     May    have    one-half     (  y,  )     inch    bright    sap     on    ei'her 

1,250,000 
1,000,000 

4,264 
3,456 

22,516 

18,246 

4,508 
3,674 

23,800 
19,400 

edge. 

900,000 

3,127 

16,513 

3,332 

17,600 

11.     May    have    one    (1)     to    three     (3)     small    sound    knots 

800,000 

2,799 

14,779 

2,992 

15,800 

not   more    than   three-quarters    (  %  )    inch    in    diameter    if   well 
scattered    so    as    not    to    materially    affect    the    strength    of    the 

750,000 
700,000 
600,000 

2,635 
2,471 
2,093 

13,913 
13,045 
11,052 

2,822 
2,650 
2,235 

14,900 
14,00? 
11,800 

piece. 

500,000 

1,765 

9,318 

1,894 

10,000 

White  and  Norway  Pine.                                  * 

450,000 

1,601 

8,452 

1,724 

9,100 

12.     White    sap    will   not   be    considered    a    defect.     1A    small 
amount    (not    more   than    ten    [10]    per    cent)    of    stained    sap 

400,000 
350,000 
300,000 

1,436 
1,248 
1,083 

7,584 
6,589 
5,721 

1,553 
1,345 
1,174 

8,200 
7,100 
6,200 

will   be  permitted. 

250,000 

907 

4,788 

985 

5,200 

13.     Round,   sound   knots,   not   larger  than   one    (1)    inch   in 

Size-B.  & 

S.  Gauge. 

diameter    and    not   more    than    six    (6),    well    scattered    in   any 

0000 
000 

745 
604 

3,935 
3,190 

800 
653 

4,220 
3,450 

piece,   will  be  permitted. 

00 

482 

2,544 

522 

2,760 

Long  Leaf  yellow  Pine  and  Fir. 

0 

388 

2,051 

424 

2,240 

14.     Bright    sap    will    not    be    considered    a    defect      A    small 

1 

2 

303 
246 

1,599 
1,301 

328 

270 

1,735 
1,425 

amount    (not   more    than    ten    [10]    per    cent)    of    stained   sap 

3 

190 

1,004 

206 

1,090 

will  be  permitted. 

4 

155 

820 

170 

900 

15.     Round,    sound   knots    not   larger   than    one    (1)    inch    in 

5 

126 

668 

140 

740 

diameter   and    not    more   than   six    (6),    well    scattered   in    any 

6 
8 

103 
68 

544 
359 

115 

78 

610 
410 

piece,   will  be  permitted. 

16.     Small    pitch    pockets,    not    over     four      (4)      inches     in 

length,  will  be  permitted. 

FIRE  AND  WEATHER  PROOF  WIRE. 

Inspection  and   Acceptance. 

TRIPLE  BRAID—  BLACK 

OUTSIDE. 

17.     All  over-shipments  of  any  size  of  lumber,   on  any  order, 

will   be  entirely  at  the  risk  of  the  shipper,  and  the  purchaser 

Capacity. 

Stranded. 

Solid. 

will  not  be  responsible  for  their  safe  keeping. 
18.     No   allowance   whatever   will    be   made   for    material    re- 

Circular 
Mills. 

Lbs.  per 
1000  ft. 

Lbs.  per 
mile. 

Lbs.  per    Lbs.  per 
1000  ft.           mile. 

jected.     Freight  charges   on   rejected   lumber  and    75   cents  per 

1,000,000 
900,000 

3,860 
3,520 

20,400 
18,600 

thousand  feet  for  handling  culls  at  destination  will  be  deducted 

800,000 

3,180 

16,800 

from    shipper's    invoice.       If    shipping    instructions    are    issued 

700,000 

2,820 

14,900 

by  shipper  for  rejected  material,   full  freight  charges  will  fol- 
low shipment  to  destination.     A  charge  will  be  made  for  saw- 

600,000 
500,000 
450,000 

2,350 
1,990 
1,820 

12,400 
10,500 
9,600 

ing  material  shipped  in  multiple  lengths. 

400,000 

1,650 

8,700 

19.     Inspection  reports  showing  the   result  of  inspection   will 

350,000 

1,440 

7,600 

be   mailed  to  the  shipper   within   two  weeks  after   the   unload- 

300,000 
250,000 

1,270 
1,060 

6,700 
5,600 

ing  and  inspection  of  the  material,  and  rejected  material   will 

Size-B.  & 

S.  Gauge. 

be   held   for    thirty    days    from    the   date   of   the    inspection    re- 

0000 

900 

4,750 

862 

4,550 

port  free  of  charge,  during  which  time  the  shipper  is  expected 
to  give  disposition  to  the  purchaser  for  such  rejected  material. 

000 
00 
0 

735 
583 

480 

3,880 
3,080 
2,530 

710 
562 
462 

3,750 
2,970 
2,440 

Failure  on  the  part  of  the  shipper  to  give  the  purchaser  such 

1 

355 

1,870 

340 

1,800 

disposition   will    be   considered    as    authority    from    the    shipper 

2 

290 

1,540 

280 

1,480 

to  charge  storage  after  the  expiration  of  the  thirty  days  men- 

3 

4 

240 
195 

1,270 
1,030 

230 
190 

1,220 
1,000 

tioned,    at    the    rate    of    25    cents    per    thousand    feet    per    day. 

5 

160 

845 

155 

820 

Such   charge  will   be   deducted  from    the   invoice   of  the   shipper 

6 

132 

695 

127 

670 

when  final  settlement  is  made  for  the  lumber. 

8 
10 

87 

460 

85 
60 

450 
315 

12 

42 

220 

14 

30 

160 

STANDARD  WEIGHTS. 

16 

24 

130 

WEATHERPROOF  WIRE. 

18 

19 

100 

Approximate  Weights. 
SOLID. 


Size. 
B.  &S. 
Gauge. 
0000 

Double  Braid. 
»  Lbs.  per       Lbs.  per 
1000  ft.            mile. 
723                 3,817 

Triple  Braid. 
Lbs.  per     Lbs.  per 
1000  ft.             mile. 
767                  4,050 

SLUW-i5UKJNlJNU     WIKJIJ. 

Approximate   Weights. 
TRIPLE  BRAID. 

000 

587 

3,098 

629 

3,320 

Capacity. 

Stranded. 

Solid. 

00 

467 

2,467 

502 

2,650 

Circular 

Lbs.  per 

Lbs.  per 

Lbs.  per    I 

L,bs.  per 

0 

377 

1,989 

407 

2,150 

Mills. 

1000  ft. 

mile. 

1000  ft. 

mile. 

1 

294 

1,553 

316 

1,670 

1,000,000 

3,980 

21,000 

2 

239 

1,264 

260 

1,370 

900,000 

3,640 

19,200 

3 

185 

977 

199 

1,050 

800,000 

3,280 

17,300 

4 

151 

795 

164 

865 

700,000 

2,920 

15,400 

5 

122 

646 

135 

710 

600,000 

2,460 

13,000 

6 

100 

529 

112 

590 

500,000 

2,080 

11,000 

8 

66 

349 

75 

395 

450,000 

1,900 

10,000 

9 

54 

283 

62 

325 

400,000 

1,700 

9,000 

10 

46 

241 

53 

280 

350,000 

1,500 

7,900 

12 

30 

158 

35 

185 

300,000 

1,310 

6,900 

14 

20 

107 

25 

130 

250,000 

1,120 

5,900 

16 

16 

83 

20 

105 

Size-B.  &  S. 

Gauge. 

18 

12 

64 

16 

85 

0000 

960 

5,070 

925 

4,890 

20 

9 

48 

12 

65 

000 

785 

4,150 

760 

4,020 

00 

625 

3,300    • 

600 

3,170 

0 

510 

2,700 

495 

2,610 

WEATHERPROOF  IRON 

WIRE. 

1 
2 

380 
335 

2,000 
1,770 

365 
320 

1,930 
1,690 

Approximate 

Weights   Per   Mile. 

3 

280 

1,480 

270 

1,425 

4 

230 

1,220 

220 

5,160 

Iron  Wire  Gauge.                  Double  Braid. 

Triple  Braid. 

5 

195 

1,030 

190 

1,000 

No 

.  4 

860 

940 

6 

165 

870 

160 

845 

6 

665 

740 

8 

105 

555 

100 

530 

8 

470 

525 

10 

80 

420 

9 

400 

450 

12 

55 

290 

10 

350 

400 

14 

40 

210 

12 

225 

260 

16 

30 

160 

14 

145 

175 

18 

24 

130 

GENERAL  INDEX 


[Descriptions  are  indexed  by  page  numbers  and  have  the  prefix  p.    Illustrations  are  indexed  by  figure  numbers  and  have  no  prefix.] 


A 

Absolute  Permissive  Block  System,   p    64..  511 

Accessories: 

Batteries,    pp.    326-345 9243-2415 

Circuit  Controllers,    pp.    346-362 !!2416-2549 

Indicators,    pp.     363-383 2550-2674 

Lamps,   Lanterns  and  Attachments,  pp.   384-391  2675-2743 

Lightning   Arresters,    pp.    393-397 2744-2788 

Locks,    pp.    398-410 2789-2859 

Power  Generation  and  Distribution,  pp.   411-438.2860-3043 

Relays     pp.    439-450 3044-3103 

Relay  Housings  and   Cable  Posts,   pp.   451-461. .  .3104-3223 

Signals  and  Fittings,   pp.    462-477 3224-3478 

Slots,     Electro-mechanical,    pp.     478-480 3479-3493 

Switch    Machines    and    Switch    Stands,    pp.    481- 

„  4813.     •  •  v 3493-3514 

Testing    Instruments,    pp.    484-489 3515-3558 

Tools    and    Appliances,    pp.    489-496 3559-3627 

Track  and  Pipe  Line  Insulation,   pp.   497-500 3628-3690 

Train    Stops,     pp.     501-502 3691-3700 

Trunkmg   and    Conduit,    pp.    503-509 3701-3883 

Wire,     pp.     510-518 3884-3899 

Adjustable  Crank    1172-1173 

Air  Compressors 2916-2917,   2920,    2923-2924,  2933-2934 

Air   Compressor   Plant,    Piping   and   Connections 2948 

Air   Pipe,   Alcohol   Inlet   Valve 2949 

Air    Reservoir 2921-2922,    2928 

Alternating   Current    Signaling: 
Discussion,   pp.    91-92 

Double   Rail    Circuit 604-  605 

Installation  on  Cumberland  Valley,  p.  93 610-  612 

Single    Rail    Circuit 603 

Ammeters 3515,   3520,   3525,   3528,   3534,  3535,  3537,  3542,  3556 

Ammeter   Symbol    212 

Annunciators: 

Bryant  Zinc  Co 2570-2571,  2580 

Circuits     2556-2561 

Federal     Signal     Co 2604 

General    Railway    Signal    Co 2597-2603 

Railroad   'Supply    Co.. 2551     2564-2569,    2587-2589,    2593-2596 

Union  Switch  &  Signal  Co 2550,   2562-2563,  2577-2578 

United   Electric  Apparatus    Co 2552-2555,   2583-2586 

Approach  Locking. .  .2059-2060,  2072-2073,   2075,  2084-2085,  2088 

Arrangements,    Typical    Block    Signals 308-  324 

Atchison  Topeka  &  Santa  Fe: 

Bootleg      3732-3772 

Interlocked   Switch    1618 

Location    of    Insulated    Joints    and    Trunking...   479-  483 

Relay    Box    Details 3028-3215 

Split    Point    Derail 1619 

Turnout   and   Crossover   Protection 479-  483 

Automatic   Block   Signals: 

Alternating  Current  Systems,   pp.    91-93 603-  612 

Control    Circuits,    pp.    55-64 484-  511 

Mechanisms,     pp.     64-90 512-  602 

Track   Circuit,   pp.   46-55 406-  483 

Automatic    Train    Stops- 669,    702-703     709     3691-3700 


Battery  Charging  Switches: 
Federal    Signal    Co 


6  2962 


si™  n     r 

signal  Co.,   pp.   430-43 

Union  Switch  &  Signal  Co 


B 


Back    Spectacles     3472 

Balance  Levers,  Pipe  and  Wire  Connected   Signals.  1662- 

Balance    Lever     Stand 3469 

Baltimore   &   Ohio: 

Normal  Danger  Three-position   Circuit 

Three-Position  Signal  Operation  from  two  levers, 

p.     160 1022 

Base  for  Signal  Posts,  R.  S.  A.  Standards 3314- 

Battery: 

Arrangement  of   Cells   for   Track   Circuit 422- 

Primary,   pp.    335-340 2297- 

Storage,    pp.    326-334 ; 2243- 

Symbols    for    201- 

Track    Circuit    Output 

Battery    Box    2365-2369,  2393, 

Battery    Brush     

Battery  Charging  Set,  Mercury  Arc  Rectifier 2906- 


•3476 
•1663 
•3471 

506 

1024 
3315 

429 

2351 

2296 

202 

430 

2412 

3574 

2908 


Battery   Connectors    .............  2352 

Battery  Copper,   R.   S.   A.   Standard,   pp."336-337;  !.'.  '2316 
Battery    Elevators  ...................  2364-2366,    2372-2374, 

.Battery    Knife    ......................... 

Battery  Shelters     .  ...    .......  2365-2371,  2375-2395;  '2397 

Battery    Shelter    Symbol  ____  04 

Battery     Syringe     ................. 

Battery    Vault    ..........................  "'2405 

''  .................  2400-2404,'  '2407 


29B 

« 

2361 
2318 
2396 
3575 

2415 
Q« 

357? 
2406 
2409 

Communicating,    Manual    Block    Signals.  .  . 

Highway   Crossing,   pp.   313-317  ...........  2146,    2153,   2155 

2168,  2170-2195,  2197-2210,  2215,   2217-2224,  2230    2239-2241 
Tower  Annunciators  ..................  2553-2554,'  2567-2568 

g  ades   .  .    .................................  3341-3343,   3361-3369 

Blade    Clasps    .......................................  3461-3462 

Block    Instruments: 
Controlled   Manual. 

General  Railway  Signal  Co  .............  361-  364 

Union  Switch  &  Signal  Co  ..................      346-  354 

Manual    Signals     ................................  343.  345 

Block   Signaling,    Semaphore    Indications  ............  225-  235 

Block  Signals: 

Automatic,    pp.    46-93  ..........................       406-  613 

Controlled   Manual,   pp.    27-45  .........  "  345-  405 

For  Electric  Railways,  pp.  94-125  ......  "   614-  713 

Manual,    pp.    24-27  .............................  ',',  325-  345 

Numbering    ......................................  3454-3455 

Typical    Arrangement     ......................  308-  324 

Block   Signal  Markers,  Illuminated  ..................  3563-3564 

Bolt   Connectors   for  Storage   Batteries  ...........  ..3570-3572 

Bolt    Locks,    pp.    203-205  ......  1482,    1484,    1707-1731,    1756-1757 

Bolt   Lock   Symbol  ................................  118,126-128 

Bond    Wires    ........................................          3594 

Bond   Wire   Arrangement  .......................  .  '  ',  "3610-3618 

Bond  Wire   Protectors,   p.    464  .....................     3619-3697 

Bonding    Drills    ..........................  3595-3598,    3600-3601 

Bootlegs  ..............  3722-3772,   3852-3863,  3868-3875,   3880-3881 

Boston,   South  Station,   Diagram   of  Track  and  Sig- 
nals    ...............................................  1991 

Boston  Elevated: 

Alternating  Current  Signal  Installation,  pp.  121- 

124     ...............................  ;  ----  700-703,  706-  709 

Automatic   Train    Stops  ..........................  3593 

Drawbridge     Protection  ..........................  2014-2016 

Switchboard  and  Motor  Generators  ..............  2887 

Box  Cranks    .........................................  1154-1160 

Box  Crank  Leadout,  p.  157  ...........................  1016-1020 

Box  Wheels    .........................................  1371-1386 

Bracket   Post    Signals,    Locations  .....................  285-300 

Bridge    Circuit    Controllers  ..........................  2.  ~>  37  -:.'.">  4  9 

Bridge    Couplers    ....................................  1739-1744 

Bridge  Lock: 

Gravity   ...............................  1747-1749,   1753-1755 

Tumbler     ........................................  1736-1738 

Bridge    Signals    .....................................   301-  305 


Cable  Connections   to  Mechanism   Case    3015 

Cable   Posts 3108,    3109,    3124-3130,    3135, 

3152-3154,    3156-3164,    3173,    3175,    3177,    3179.    3185-3190,    3208 

Cable   Post    Symbol 87-     92 

Cam    Circuit    Controller    2511 

Caustic  Soda  Battery,  R.  S.  A.  Standard,  p.  340 2341-2349 

Central  Railroad  of  New  Jersey,  Mercury  Arc  Rec- 
tifier       2914 

Chain    Wheels     1338-1403 

Channel  Pin   3605 

Channel  Pin  Gauge 3604 

Channel   Pin  Punch    3602,   3606,3608 


522 


THE    SIGNAL    DICTIONARY 


Channel   Pin    Set 3603,  3607 

Check    Locking    2079,  2081-2082 

Chicago   &  North  Western: 

Bridge  Signals,  Chicago  Terminal 1826 

Distant    Signal    Lamps 2688-2690 

Dwarf  Signals  on  Chicago  Terminal 1834 

Electric   Locking    2076 

Installation  of  Switch   Machine 1793,    1802,1813 

Lake   Street  Interlocking-  Plant 1821 

Protective   Wiring 434-  435 

Standard  Train  Order  Signals 3319 

Storage  Battery  Installation  on  Chicago  Terminal,  p.  327. 

Terminal  Power  System,  pp.  416-417 2888 

Unit  Type  Lever  Interlocking  Machine,   Chicago 

Terminal     1762 

Wire    Details 3004-3006,    3021-3025 

Chicago,   Milwaukee  &   St.  Paul: 

Adiustable    Resistance    for    Storage   Battery    on 

Track    Circuit 2248-2249 

Number  Plate  for  Block  Signals 3460 

Switch    Rod     Insulation 3687T368S 

Trunking    Stake 3876-3879 

Chloride   Accumulator: 

Accessory    Parts    3563-3572 

Cells    2250-2252,    2256-2257,   2259-2260 

Chuck  for  Bond  Wire  Drills 3599 

Chutes,   Battery 2317-2371,   2374-2387,   2394-2395,   2397-2399 

Circuits: 

Control,    pp.    55-64 484-  510 

Operating: 

Electro-Pneumatic  Interlocking  U.   S.   &  S'.  .1968-1975 

Electro-Pneumatic  Push-Button  Machine 2003-2005 

Electro-Pneumatic    Signal   Mechanisms 601-  602 

Eureka  Signal  System 634-  636 

G.   R.   S.   Interlocking  Plant 1767 

G.     R.    S.,    Model    2 — A     Signal    Mechanism 

552-553,     2053-2054 

Hall  Electro-Gas  Signal  Mechanism 

Hall  Style   "H,"    Signal  Mechanism 567-  568 

Kinsman   Automatic   Train   Stop 3695-3700 

Kinsman   Block   System 631 

Mercury  Arc  Rectifier 2900,  2915 

Nachod'  Signal   System 614,    617 

Power  Distant   Signal 2078 

Semi-Automatic  Interlocking   Signal 1769 

Solenoid     Signal 712 

U.    S.   &   S.  Electric   Interlocking.  .1882-1884,  1890-1903 

U.  S'.  &  S.,  Style  "B,"  Signal  Mechanism 

534,    536,    2045-2046 

United  States  Electric  Signal  System 625-  626 

Track,  pp.   46-55 406-  483 

Circuit  Breakers,  pp.  435-436 1770,  2994,  2996 

Circuit    Controllers: 

Application  to  Saxby  &  Farmer  Machine 2049-2050 

Automatic    Signal,    Hall    Signal    Co 527-  528 

Bridge    Circuit    Controller 2537,  2549 

Electric  Switch  and  Lock  Movement,  U.  S.  &  S..  1878-1881 

Electro-Pneumatic  Signal  Mechanism 592-  593 

Floor  Push 2498-2503,  2507 

Fouling  Bar,   p.    357 2489 

Hand    Circuit    Controller 2492 

Knife  Switches 2504,   2508,  2510 

Magnetic    Circuit    Controller 2493,2497 

Signal    Circuit    Controllers,    p.    354 24fi3-2^86 

Strap  Keys 2509,  2512-2531,  2533-2536 

Symbols   for    169-  179 

Switch   Boxes,    pp.    346-353 2416-2462 

Table  Circuit  Controller 2490-2491,   2505 

Track  Instruments,   pp.    356-357 2486-2488.   2532 

Circuit  Plans,  Standard  Symbols 139-  224 

Clamps: 

R.  S.  A.  Standard 3331,  3333,  3335-3340 

Signal    Post    1647-1661 

Clearance  for  Signals  Between  Tracks,  Sunset  Lines          3448 
Clearance   Diagram,    New    York    Central    &   Hudson 

River 3396 

Clock-Work   Mechanism   for   Crossing   Bell,    p.    317.  .2211-2212 

Clock -Work    Time    Release 2858-2859 

Clutch   Magnet,    American    Electric    Interlocking 1953 

Coleman  Lock  and   Block   System,  Union   Switch  & 

Signal  Co.,  pp.    28-39 348-  360 

Communicating  Mechanisms,    Manual   Block    Signals  325-  327 
Compensators : 

Pipe,     pp.     166-169 1163-1178 

Wire    1409-1412 

Compensator  Base 1167 

Compensator  Symbol 121 

Concrete    Foundations ........... 1263-1264 

Concrete  Interlocking  Tower 1929 

Condenser,    Symbol    for 200 

Conduit,   Fibre.    Standard  Fittings  and   Connections, 

pp.  506-507 3822-3850 

Connectors,  Battery  Wire 2352-2361 

Control  Circuits: 

Alternating  Current  Block   Signaling: 

Boston  Elevated 70S 

Hudson  &  Manhattan 653 

Interborough  Rapid  Transit  Subway 675 

New  York   Central  Electric  Zone 641 

New  York,  New  Haven  &  Hartford 698 

San  Francisco,  Oakland  &  San  Jose 674 

"Washington  Water  Power 666 

Blake  Dispatchers'  Signal  System 729 

Direct   Current   Automatic   Block   Signaling,   pp. 

55-64     484-  510 

Electro-Pneumatic    Interlocking 2000-2002,     2009-2013 

United   States   Electric   Selective   Signal    System  714 

Controlled  Manual  Signaling: 

Coleman    Lock    and    Block,    pp.    28-34 348-  360 

Electric  Train  Staff,  pp.  38-45 374-  405 

G.    R.    S.,   pp.    34-36 361-  370 

Pennsylvania  R.  R.,  pp.  36-38 371-  373 

U.    S.   &   S.   Electro-Manual,   pp.    27-28 346-  347 

Copper   Terminals,    Gravity   Battery,   pp.    336-337 

2297,    2303-2311,    2316-2318 


Counter 3543-3544 

Couplings,  Pipe,  pp.   161-163 1026-1133 

Cranks,    pp.    164-166 1134-1162 

Crank     Pins 1161-1162 

Crank    Stands 1139-1153 

Crank     Symbols 129-  131 

Cross  Arm.  Standard  on  Southern  Pacific 3013 

Crossing,  Protective  Wiring 468-  471 

Crossing    Gates,    p.    319 2226-2229 

Crossing   Gate   Lamp 2729 

Crossing    Gate    Symbol 44 

Cumberland   Valley,   Alternating   Current   Signal   In- 
stallation, p.  93 610-  612 

Cut    Section,    Track    Circuit 409-411 


D 

Deflecting  Bars,  pp.  169-170  1179-1204 

Deflecting  Bar  Leadout,  p.   157 1007-1009 

Delaware  Lackawana  &  Western: 

Crossing   Bell    Layout 2097 

Electric    Locking 2071 

Electro-pneumatic  Interlocking  Bridge  Signals..  3447 

Wiring  for  Polarized  Cut  Section 499 

Derails,    pp.    195-196 1621-1638 

Derail    Symbols 103-  108 

Detector  Bars,  pp.  189-193 1543-1617,  1796 

Detector   Bar    Symbol 117 

Detector  Locking 2070-2071,  2073,  2087 

Disk  Indicators 2575;  2581,  2582,  2584,  2595-2596,  2599 

Disk  Signals: 

Hall  Signal  Co. 

Details    3419-3420,  3435 

Mechanism,    p.    64 H12-  516 

Standard    Indications 242-  249 

Union  Switch  &  Signal  Co.  Mechanism,  p.  65 517-  520 

Dog  Charts,   pp.    134-143 740-789,  1829 

Double  Slip  Switch.  Method  of  Plating  and  tieing. . .  1485 

Double  Track  Crossing  Bell  Layouts 

2089,  2092,  2094,  2098,   2103,  2106,  2111,   2242 

Drafting,    Standard   Symbols l-  224 

Drawbridge    Interlocking,    pp.    206-209 1736-1761,  2014-2016 

Drills,    Bond   Wire 3595-3598,  3600-360] 

Drop    Annunciators 2551-2555,  2562-2566,  2569,  2571 

Dwarf  Interlocking  Machine,  p.  156 1004 

Dwarf  Interlocking  Machine  with  Electric  Locks.:..   355,  2796 
Dwarf  Signal:' 
Electric. 

American   Railway   Signal   Co 1941,  1944,  1946-1951 

Federal   Signal   Co 1921-1922,  1924 

General  Railway  Signal   Co 1830-1840 

Union  Switch  &  Signal  Co.,  p.  246.1887-1888,  1908-1919 

Electro-Pneumatic 1983-1988 

Low  Pressure  Pneumatic 2032,  2038-2039 

Mechanical .'. 1668-1681,  1684-1686 

E 

Electric  Interlocking: 

American  Railway  Signal  Co.,  pp.   249-254 1928-1954 

Federal  Signal  Co.,  pp.  247-248 1920-1927 

General  Railway  Signal  Co.,   pp.   210-229 1762-1840 

Union  Switch  &  Signal  Co.,  pp.  230-246 1841-1919 

Electric  Interlocking  Machine,   Application   of  Hand 

Screw    Release    2835 

Electric  Lights  for  Signal   Lamps 2709,  2715,  2717-2721 

Electric   Locking,   pp.    280-296 2055-208S 

Electric   Locks: 

Controlled   Manual    System 355,  357-  358 

G.   R.    S 2793,  2795-2796,   2803,   2805-2807 

U.  S.  &  S 2794,  2801-2802,  2804,  2808-2809,  2810-2812 

Electric  Railway  Signals: 
Installations. 

Boston  Elevated,  pp.   121-124 700-703,  705-  709 

Hudson   &  Manhattan,  pp.    108-110A 653-  661 

Interborough   Rapid  Transit  Elevated   Lines, 

pp.    124-125    710-  712 

Interborough  Rapid  Transit  Subway,  pp.  114- 

118     675-  692 

Lehigh  Valley  Transit,  pp.  106-107 645-  648 

Long  Island,   p.    119 693-  695 

New  York  Central  Electric  Zone,  pp.  104-106.   637-  643 
New  York,  New  Haven  &  Hartford,  pp.  120- 

.121 698-  699 

Pennsylvania  Tunnel  &  Terminal,  pp.  110-111  662-  665 
San    Francisco,    Oakland   and    San   Jose,    pp. 

113-114    672-  674 

Washington  Water  Power,  pp.  111-112 666-  671 

Waterloo  and  City  (London,  England),  p.  125  713 

West  Jersey  &  Seashore,  p.  119-120 696-  697 

Systems. 

Eureka,   pp.    102-103 632-  636 

Kinsman,    pp.    99-102 627-631 

Nachod,    pp.    94-96 614-  618 

United  States  Electric,  pp.  96-99 610-  626 

Electric  Train  Staff  System,  pp.  38-45 374-  405 

Electro-Gas  Signal  Mechanism,   Hall   Signal  Co.,  pp. 

85-87    583-  590 

Electro-Manual  System,  Union  Switch  &  Signal  Co., 

pp.    27-28    346-  347 

Electro-Mechanical  Interlocking,  pp.  276-277 2041-2044 

Electro-Mechanical  Slots,  pp.  478-480 3479-3492 

Electro-Pneumatic  Interlocking,  pp.   254-271.. 1955-2028 

Electro-Pneumatic    Plant   Connections 2936 

Electro-Pneumatic   Relays    3097-3100 

Electro-Pneumatic   Signals: 

Bridge,  D.  L.  &  W 3447 

Circuit  Controller    2482-2483 

Motion  Plate  Pole  Changers 2464-2474 

Slide  Mechanism    689-  692 

Union  Switch  &  Signal  Mechanism,  pp.  87-93 613 

Electro-Pneumatic  Three  Pressure  By-pass  System.  2935 

Electrolyte  in  Storage  Batteries,  pp.  327,  329. 

Elevators,   Battery    2364-2366,    2372-2374,  2396 


THE  SIGNAL  DICTIONARY. 


523 


Engines,    Gasoline 2856-2870,   2874-2875,   2S77-28S2,  2884-2885 

English  Practice: 

Arrangement    of    Signals 306-  307 

Manual  Block  Signals,   pp.   25-27 339-  345 

Erie,  Power  Operated  Signals  at  Mechanical  Plants.  2047 

Exide  Storage  Battery 2265-2274 

Expansion   Joint,   Air   Compressor 2918-2919,  2926-2927 


Facing  Point  Lock 1479-1483 

Filler   Blocks    3344-3351,  3357-3360 

Flange    Unions 2944,  2947 

Flask  for  Liquid  Gas,  Hall  Electro-Gas  Signals 587 

Floor   Push 2498,  2503,  2507 

Floor   Push   Symbol 186 

Foreign   Current,   Protection   Against 476-  478 

Fouling  Bar,   p.   357 2489 

Fouling-  Protection 431-467,   472-475,  479-  483 

Foundations: 

R.  S.  A.  Standards 3428-3434 

Pipe  Carrier  and  Compensator 1263-1278 

Signal. 

Cast  Iron 3440 

Concrete     3441-3443 

Fresnal  Lenses  for  Signal  Lanterns 2675-2676,  2730-2734 

Friction    Clutch,    G.    R.    S.    Switch   and   Lock   Move- 
ment     1782-1786 

Front    Rods 1532-1542,   3661-3664 

Fuse  Copper  Terminal 3027 

Fuse    Symbol 197 

G 

Galvanometer  Relay 3089 

Gasoline  Engine  Generator  Sets,  p.  412 

2866-2870,    2874-2875,    2882,  2884-2885 

Gauge,    Channel    Pin 3604 

Gauntleted    Tracks,    Protective    Wiring 466-  467 

Generator   2860,  2864,   2871,  2876 

Generator   Symbols 206-  211 

Gill  Selector 713 

Governor,  Air  Compressor 2931 

Gravity  Battery,  pp.   336-337 2297-2324 

Great  "Western  Railway  of  England: 

Bolt   Lock 1707-1709 

Dwarf   Signal 1684-1685 

Ground   Lock 1729-1731 

Inside  Connected  Facing  Point  Lock 1480 

Parallel    Bars 1598-1603 

Parallel  Compensator 1166 

Grey  Iron  Castings,  R.  S.  A.  Specifications,  p.  164. 
Ground: 

Paragon    Cone 2787 

Symbol    for 218 

Ground  Post  Signals,  Locations 277-284,  297-  300 


Interlocking: 

Mechanical,   pp.    134-209.  ......  740-1761 

' 


H 


Hand  Car  Axle  Insulation 

Hand    Circuit    Controller 

Hand  Screw  Release 2835-2839,  2843-2848,  2S53-2856, 

Hand  Signals 2738- 

Highway  Crossing  Signals: 

Arrangements  of  Circuits,  pp.  298-303 2089- 

Hoeschen   System,   pp.   320-324 2232- 

Interlocking  Relays,  pp.  303-308 2119- 

Signs  and  Bells,  pp.  309-320 2146- 

Symbol   for 

Hose  Connection 

Hudson  &  Manhattan: 

Alternating  Current  Signal  Installation,  pp.  108- 

110 653 

Electro-Pneumatic    Interlocking,    Church    Street 

Terminal    

Track  Plan,  Locking  Sheet,  and  Dog  Chart. ...  .1827 

Hydrometer    3566 


3690 
2492 
2857 
2743 

2118 
2242 
2145 
2231 
97 
2925 


-  661 

1982 
1829 
3569 


I 


Illinois  Central,  Bootleg 3868-3869 

Illuminated  Highway  Crossing  Signals,  pp.  310-312.. 

2196,    2213-2214,    2225-2231,    2264-2267 

Impedence  Bonds,  p.  433 2981,2982 

Impedence   Bond   Symbol 40,  198-  199 

Impedence  Coil 677 

Indications,    Signal,   pp.   4-20 225-  307 

Indicators: 

Annunciators  and  Tower  Indicators,  pp.  363-376.  .2550-2629 

Switch   Indicators,   pp.    377-383 2630-2674 

Symbols  for   139-  168 

Induction  Coil,  American  Electric  Interlocking 1931-1932 

Initial  Charge,  Instructions  for  Storage  Batteries,  pp. 

327,    328,    329. 

Inspection  of  Storage  Batteries,  pp.  328-329. 
Insulated   Joints: 

Location    for    Siding    and    Crossovers,    A.    T.    & 

S    F 479-  483 

Symbols    34-     39 

Insulation: 

Axle   3690 

Front  Rod 3663-3664 

Lock  Rod 3661-3662" 

Pipe    Line 3653-3658,   3665-3674,  3689 

Rail   Joints,   pp.   497-498 3628-3642 

Switch   Rod 3659-3660,    3675-3677,  3680-3688 

Switch   Wedge 3645-3652 

Wire    3884-3899 

Insulators,    Glass 3019-3020 

Interborough  Rapid  Transit: 

Electro-Pneumatic  Slide  Signal 

Elevated  Lines  Signaling,  pp.  124-125 710-  712 

Junction  Box 3035-3036 

Power    Switchboard 2899 

Subway  Signaling,  pp.   114-118 675-  692 


2139 


Bryant  Zinc,   pp.   305-307... 

Han,  pp.  303-304  ......................  ::.:::::::     - 

Railroad   Supply    ......................  2128-2138,  2140-2142 

U.  S.  &  S.,  pp.  303-308  ......................  2119-2123-2144 

United  Electric  Apparatus  ....................       2143-2145 


Jaws     Pipe 1034-1133 

Jaw  Pins 1041-1044 

Johnson  Interlocking  Machine,  pp.   152-154 903-  932 

Johnson  Interlocking  Machine,   Application  of  Elec- 

trie  Lock  28G4 

Joint,   Pipe    1026 

Junction    Box: 

If0.n   3035-3036,  3039-3041 

Reinforced  Concrete  3821-3840 

Symbol  for   73 

Trunking    Line 3818-3820 

Wood   ,< 3037-3038 

Junction   Strips 3042-3043 

K 

Knife    Switches 2504,    2508,  2510 


Ladders     for     Signal     Posts,     R.     S.     A.     Standard 

3306-3311,     3316-3318 

Ladder   Foundations,    R.    S'.    A.    Standard 3477-3478 

Lake    Shore    &   Michigan    Southern: 

Junction     Box 3037-3038 

Line  Wire  Arrangement  for  Automatic  Signals.  300-' 

Lamp  Indicators,  Great  Western  of  England 2620-2621 

Lanterns   2731,  2736-2737 

Lantern     Signals 2738-2743 

Latch    Lock,    Standard    Interlocking    Machines 853-  854 

Latch  Rod,  Saxby  &  Farmer  Machine 792-  793 

Lazy    Jack    Pipe    Compensator 1165-1168,1171 

Leadout: 

Manual    Block    Signals 328-  338 

Mechanical    Interlocking,    pp.    157-160 1007-1025 

Symbols    for 136-  138 

Lead-Sulphuric  Acid   Storage  Battery,   Operation  of 

2243-2246 

Left-Hand  Quadrant  Signal,  New  York,  New  Haven 

&   Hartford .\ 3438-3439 

Lehigh  Valley  Transit  Co.,  Alternating  Current  Sig- 
nal   Installation,    pp.    106-107 645-  648 

Lever    Lights 2616 

Lever  Operation  of  G.  R.   S.  Interlocking  Machine.  .1765-1766 
Lightning  Arresters: 

Arc  Damp,  pp.   392-393 2750 

Bryant  Zinc 2755,  2716 

Carborundum    2763 

Federal  Signal  Co 2786 

General  Electric,   p.    392 2749,    2768,   2774 

G.   R.   S.,    p.    392 2748 

Hall    2769,  2773 

Railroad  Supply  Co 2753,   2764,   2775-2780,   2782-2785 

Symbol    for 216 

U.    S.    &    S.    Spark   Gap,    p.    392 2744,  2747 

U.    S1.    Electric 2781 

Vacuum    2754 

Lightning-  Arrester  Box,  Symbol  for 80 

Light    Signals 649-652,    659-665,    693-695 

Links      1045-1121 

Location     of     Signals     with     Reference     to     Tracks 

Governed    277-  307 

Locks: 

Electric,    pp.    398-401 2789-2812 

Staff   Lever    396-  399 

.       Switch,    pp.    402-404 2813-2830 

Symbols    for 139-  168 

Time,  pp.  405-410 2831-2859 

Lock  Plunger,  G.  R.  S.  Switch  and  Lock  Movement..  1776 

Lock    Rods 1522-1527,    1532-1542 

Locking,    Electric,    pp.    280-296 .- 2055-2088 

Locking  Details: 

Johnson     Machine     903-  929 

National    Machine 935-1003 

Saxby  &  Farmer  Machine ' 794-  845 

Standard  Machine 855-  901 

Locking  Sheets,   pp.   134-143 740-789,    1828 

Long-   Island   Railroad: 

Alternating     Current     Signaling     on     Electrified 

Lines,    p.    119 •. 693-  695 

Arrangement  of  Double  Slip  Switch 14S5 

Bracket    Signals 561 

Cast    Iron    Rail    Brace 1529 

Malleable    Iron    Bootleg    Cap 3866-3867 

Long-Time   Burners   for   Signal   Lamps 

2699-2701,     2712.     2722-2724 

Low  Pressure  Pneumatic  Interlocking,  pp.   272-275.  .2029-2040 
Lug: 

Pipe    1032,    1047-1121 

Switch    Point     1486-1512 

M 

Machinery  Steel,  R.  S.   A.  Specification,  p.  164. 

Machines,   Mechanical  Interlocking 143-156,  790-1006 

Magnetic    Circuit    Controller 2493-2497 

Magneto    Generator   Used    for    Crossing   Signal 2232-2237 

Magneto    Testing    Set 3549-3550 

Mail  Crane,  Symbol  for 

Malleable  Iron  Castings,  R.  S.  A.  Specifications,  p.  164 
Manipulation    Charts 784-  785 


524 


THE  SIGNAL  DICTIONARY. 


Manual   Block  Signals: 

Communicating:   Mechanisms,    p.    24 325-  327 

English    Practice,    pp.    25-27 339-  345 

Leadouts,  pp.  24-25 328-  338 

Marker   for  Automatic  Block   Signals 3463-3464 

Mechanical  Interlocking: 

Bolt   Locks,    pp.    203-205 1707-1731 

Chain    Wheels 1338-140S 

Cranks,    pp.    164-166 1134-1162 

Compensators,    pp.    166-169 1163-1178 

Deflecting   Bars,    pp.    169-170 1179-1204 

Derails,    pp.    195-196 1618-1619,    1621-1638 

Detector  Bars,   pp.    189-193 1543-1617 

Drawbridge   Interlocking,   pp.    206-209 1736-1761 

Leadouts,    pp.    157-160 1007-1025 

Machines,    pp.    143-156 790-1006 

Oil    Pipes,    p.    180 1420-1444 

Pipe  Carriers,  pp.   171-173.  .  .1205-1233,   1242-1258,  1267-1268 

Pipe  Carrier  Base,   p.   172 1234,   1239,  1268 

Pipe     Line     Foundations 1259-1278 

Pipes   and   Couplings,   pp.    161-163 1026-1133 

Principles   of  Interlocking,   pp.   134-143 740-  789 

Rocker    Shaft    Bearings 1282-1289 

Signals    1639-1706 

Slots,    pp.    205-206 1732-1735 

Switch   Operating  and  Locking  Mechanisms,   pp. 

181-189     1445-1561 

Wire   Adjusting   Screw 1307-1308 

Wire   and    Pipe    Connections 1413-1419 

Wire    Carriers 1309-1337 

Wire    Compensators 1409-1412 

Wire    Connections 1293-1306 

Mechanisms,    Signal: 

American  Bottom  Post,  p.   82 575-  579 

American  Top  Post,  pp.  81-82 572-  574 

Eureka   

Federal,   pp.    83-85 580-  582 

G.  R.  S.,  Model  "2-A,"  pp.  75-78 549-563,  606,  1814-1819 

Hall    Disk,    p.    64 512-  516 

Hall,     Electro-Gas,     pp.     85-87 583-590 

Hall.    Style   "F,"   pp.    65-69 521-532 

Hall,   Style  "H,"   pp.   79-81 564-  571 

Kinsman     

Tunnel    Signal 656-  657 

Union  Disk,   p.    65 517-  520 

Union   Electro-Pneumatic,    pp.    87-90 591-602,    1978-1979 

Union,   Style   "B."   pp.   69-72 533-544,  1885-1886 

Union,    Style    "E,"    p.    74 546-  547 

Union,    Style    "S,"    pp.    72-74 543-  545 

Union,    Style    "T,"    pp.    74-75 

United    States    Electric 620-621,    623-624 

Mercury  Arc  Rectifiers,  pp.  420-424 2900-2915 

Mercury  Contact  Relays,  p.  440 3051 

Michigan    Central: 

Bootleg     

Concrete  Foundations    1263-1264 

Detector  Bar  Driving  Piece 1557-1559 

Junction   Box 3039-3040 

Rail    Pipe    Supports 

Self-Compensating  Pipe  Run 

Two-Way   Bolt  Lock 1722-1725 

Morse    Telegraph   Circuits 325-  326 

Motion   Plate  Detector   Bars 1568-1579 

Motion  Plate  Pole  Changers 2464-2474 

Motor: 

American    Signal    Mechanism 

American  Top  Post  Signal  Mechanism 572 

G.   R.    S.,   Model    2-A,    Signal   Mechanism 558-  559 

G.   R.   S.    Switch   and  Lock   Movement 1789 

Hall    Signal    Mechanism 531-  532 

Indication,  U.  S.  &  S.,  Electric  Interlocking  Ma- 
chine     1849-1850 

Symbols    for 206-  211 

Union  Style  "B"  Signal  Mechanism 544 

Motor  Cars: 

Adams,     p.     492 3584-3586 

Buda,    pp.     493-494 3589,3591 

Concrete    Form    and   Engine 3587,3588 

Fairbanks-Morse,    pp.    491-492 3578-3583 

Rockford,    p.    494 3592,  3593 

Motor  Generator   Sets. ..  .2861-2863.    2865,   2872,   2873,  2887-2888 

Moveable  Point  Frogs  in  Double  Slip  Switch 

Multipliers   for   Voltmeters 3552 


N 


2831 
345 


2949 


Nachod   Signal   System,  pp.    94-96 614-  617 

Nashville,  Chattanooga  &  St.  Louis,  Signal  Operated 

From  Two  Switches 1696-1698 

National  Interlocking  Machine,   pp.   154-155 933-1003 

National   Interlocking  Machine,   Application  of  Time 

Lock     

Needle  Block  Instrument,  Great  Western  of  England 
New  York  Central  &  Hudson  River: 

Alcohol  Inlet  Valve  for  Air  Pipe 

Alternating  Current  Installation  on  Electric  Zone, 

pp.   104-106 637-643,   649-650 

Bootleg 3672-3723 

Detector  Bar  Layouts 1563-1567 

Distant   Switch   Signal   Layout 1692-1695 

Dwarf  Signals   on  Electric  Zone '. 1835 

Electric    Locking 2072-2073 

Electric   Locking  for  Single  Track  Crossing-*  . . .  2080 

Installation  of  Switch  Machines ]  812 

Interlocking  Machines,   Grand  Central  Terminal.  1822-1825 

Iron    Pipe    Signal   Posts 3453 

Junction   Box  in   Trunking  Line 3818-3820 

Normal  Danger  Control  Circuit  for  Tunnel  Pro- 
tection     507 

Number   Plates  for   Block    Signals 3456-3457 

Oil    Tank   and   Pump    in   Interlocking    Tower 3882-3883 

Pole  Line  Construction 3007 

Power  Operated  Signals  at  Mechanical  Plants..  2048 


Power    Switchboard 2895, 

Semaphore   Signal  Clearance  Diagram 

Standard     Connections     for     Electro-Pneumatic 

Interlocking  plant   

Standard  Controlled  Manual  Circuit  Plan. 352-354,  359- 

Standard   Interlocking  Plan 

Standard  Pipe  Line   Clearance 

Switch    and    Crossover    Protection 472- 

Three-Pressure    By-Pass     System     for     Electro- 
Pneumatic    Interlocking   Plant 

Train    Order    Signals 3323- 

Tunnel    Protection    Circuit 

Wire    Splice    1305- 

New  York,   New  Haven  &  Hartford: 

Alternating    Current    Signal    Systems,    pp.    120- 

121   698- 

Lef  t-Hand     Quadrant     Signals 3438- 

Signal    Blades    3361- 

Suspended    Signals    550,  3444- 

Switchboard   for   Electric   Interlocking   Plant 

New  York,   Ontario  &  Western: 

Arrangements  of  Circuits  and  Apparatus  at  Elec- 
tro-Pneumatic Interlocking  Plant,  p.  428,  2937,  2938, 

Battery-Charging    Circuits 

Distant    Switch    Signal    Layout 

Normal    Clear    Control    Circuits,    pp.    55-61 484- 

Normal  Danger  Control  Circuit,  pp.   61-64 502- 

Northern    Pacific: 

Automatic    Signals 551, 

Normal   Clear  Three-Position   Circuits 487' 

Number    Plate    for    Block    Signals 3456- 

Numbering  Automatic  Block   Signals,    Southern   Pa- 
cific      -•• 3454 


2898 
3396 

2936 
360 
786 

1241 
474 

2935 

3324 

507 

1306 


699 
3439 
3369 
3446 
2892 


2943 
2950 
1706 
501 
510 

563 

.  488 
3460 

-3455 


o 


Ohm-Meter,    p.     487 3539-3541 

Oil  Founts 2699-2700,  2706-2708,  2713,  2722-2723 

Oil   Pipes,   p.    180 1420-1444 

Oil    Switches,    p.    435     2997,  2998 

Oil  Tank  and  Pump  in  Interlocking  Tower 3882-3883 

Oregon    Short   Line: 

Bootleg     3724-3725 

Rail    Bond     3616-3618 

Relay     Case    Wiring 3216-3223 

Overlap: 

Interborough    Rapid     Transit .' 686-688 

Use    in    Signal    Arrangements 312,    324 


Packing    Box    1421-1424 

Paragon  Ground   Cones 

Parallel    Bars    1598-1603 

Pennsylvania  R.   R. : 

Controlled   Manual,    pp.    36-38 371-  373 

Electric    Locking    Circuits 2061-2068 

Electro-Pneumatic  Bracket   Post   Signal   Piping. 2929-2930 

Electro-Pneumatic    Ground    Post    Signal 1980-1981 

Electro-Pneumatic    Interlocking    Machine,    New 

York    Terminal 1956 

Electro-Pneumatic     Signals    Mechanically     Ope- 
rated     , 1699-1702 

Electro-Pneumatic     Signal    Mechanism 1978-1979 

Illuminated  Automatic  Block  Signal  Markers 3463-3464 

Normal    Clear    Control    Circuit 486 

Power   Room   Equipment 2891 

Semaphore  Lamp 2692-2698 

Switch    Rod    Insulation 3675-3677,3680, -3682 

Tunnel   &   Terminal   Signaling,    pp.    110-111 662-  665 

Permissive  Attachment,  Electric  Train  Staff. 375-376,  390-  392 

Philadelphia  &   Reading,  Iron  Pipe  Signal  Post 3426 

Pilot  Cell,  Use  in  Storage  Batteries,  pp.  327-329. 

Pinnacle.     R.     S.     A.     Standard 3449-3450 

Pipe     Adjusting    Screw .-* 1036 

Pipe    Carriers,    pp.    171-173. ..  .1205-1233,    1242-1258,    1267-1268 

Pipe    Carrier    Base 1234-1239,  1268 

Pipe   Guides    for   Signal   Posts 3451-3452 

Pipe     Insulation 2932 

Pipes,   Interlocking,   pp.    161-163 1026-1133 

Pipe   Line   Insulation 3653-3658,    3665-3674,3689 

Pipe    R.   S.  A.   Specifications,   p.   161. 

Plug,     Pipe     1030 

Plunger  Lock   ' 1451-1456,   1459-1478 

Polarized  Line  Circuit 501 

Polarized     Track     Circuit 417-421,    496-  oOO 

Pole  Changer: 

Electro-Pneumatic    Signal    Mechanism 592-  593 

G.   R.    S.    Switch  and  Lock  Movement 1787 

Hall     Signal    Mechanism 529-  530 

Symbol    for    

Pole    Line    Construction 3002-3014,    3016-3025 

Portable   Storage  Battery    Installation,   p.   327. 

Pot   Signal    '. 1666-1667,    1687-1691,1997 

Power   Interlocking: 

Electric,  pp.   210-254 1762-1954 

Electro-Mechanical,    pp.     276-277 2041-2044 

Electro-Pneumatic,    pp.    254-271 1955-2028 

Low  Pressure  Pneumatic,  pp.  272-275 2029-2040 

Power   Operated    Signals   at  Mechanical    Plants,    pp. 

277-279     2045-2054 

Power   Station,    Symbol   for 45 

Pipe  and  Wire  Runs,  Symbols  for 109-  116 

Pressure    Gage,    Recording 3519,  3522 

Primary  Battery: 

Banks    Track    Battery 2331-2332 

Caustic    Potash    Battery 2333 

Caustic  Soda  Cell,  R.  S.  A.  Standard,  p.  340 2341-2349 

Columbia    Track    Battery,    p.    337 2325-2328 

Edison    BSCO,    p   339 , 2337-2340,    2350-2351 

Gordon    Cell     2334-2336 


THE  SIGNAL  DICTIONARY. 


525 


Gravity,     pp.     336-337 2297-2324 

Schoenmehl     Copper     Oxide     Cell -'329 

Primary    Cutouts     2999-3001 

Principles   of  Interlocking,   pp.    134-143 740-  789 

Punch: 

Lock   Rod    3560-3561 

Channel    Pin     3602,  3606,  3603 

Push     Button,     Symbol     for 180 

Push   Button   Machine,    Electro-Pneumatic 2003-2005,2028 

Pusher    Attachment,    Electric    Train    Staff.   375-376,    383-  385 


R 


Radial    Arms     1185-1204 

Radial    Contact    Relays 3088-3091 

Rail    Brace    1529-1530 

Rail    Joints,    Insulated: 

Continuous      3640 

Keystone,    p.    497 3628 

Mock    3631-3832,    3638-3639 

Railroad    Supply   Co 3629-3630,    3633-3637,    3643-3644 

Symbols     for      34-     39 

Weber     3640-3641 

Rail    Lock,    Weaver 1750-1752 

Railway   Signal   Association: 

Instructions    for    Installation    and    Operation    of 
Storage    Batteries,    pp.    326-329. 
Specifications: 

Signal   Roundels,   p.    384. 
Lenses,    p.    385. 
Glass   Slides,   p.   385. 
Wire,   pp.  511-517. 
Wood   Trunking,    pp.    517-518. 
Standards: 

Bridge    Mast    Base 3315 

Clamp   for   Base    of   Ground    Signal   Mast.  .  .3335-33340 

Clamp    for   Semaphore   Bearing 3331-3333 

Compensator   Base    1167 

Compensator    Foundation    3429 

Cranks    1134-1138 

Crank    Foundation    3428 

Crank    Pins    '. 1161-1162 

Crank  'Stands 1139-1153 

Dwarf  Signal  Foundation    3431 

Filler    Block    to    Limit    Signal    Arm    Travel. 3357-3360 
Filler  Block  to  Prevent   Signal  Arm   Travel. 3344-3351 

Gravity   Battery   Zincs,   .p.    336 2312,2315 

Jaws      1122-1133 

Ladders 3306-3311 

Ladder    Foundation    3477-3478 

Locking   Circuits    2084-208S 

Pipe     Carriers     1242-1 254 

Pipe    Carrier    Foundations 1269,3434 

Pipe  Compensators   1165,    1177-1178 

Pipe    and    Wire    Couplings 1026-1046 

Pipe    Line    Insulation 3665-3674 

Plunger    Lock    t 1451-1456 

Semaphore     Bearing     3352-3356 

Semaphore    Spectacle    3329-3330 

Signal    Pole    Foundation 3432-3433 

Signal    Post    Base 3314 

Signal    Post    Pinnacle 3449-3450 

Spectacle    Clearance 3334 

Terminal    Block    3026 

Top   of  Ladder  Details 3316-3318 

U  Bolt  for   Semaphore   Bearing 3328 

Upper    Quadrant    Signal    Blade 3341-3343 

Wheel    Foundation    3430 

Reactances,    Track   Circuit,   pp.    432-433 

2978-2980,    2985,    2986,2989 

Reactance    Bond    654-  655 

Rectifier,    Mercury    Arc,    pp.    420-424 2900-2915 

Rectifier,    Symbol    for 203 

Reducing   Valve,    Hall   Electro-gas  'Signal 583 

Relay: 

Alternating  Current 607-608    680-684,    696 

American     3061-3062,    3081-3086 

American     Electric    Interlocking 1942-1943 

Bryant   Zinc   Co 3095 

G.   R.   S.,   p.   443 3065-3069,    3093,3103 

G.    R.     S.    Selective    Signaling 723 

Hall,    pp.    439-440 3047-3051,    3079-3080 

Interlocking,     p.     303-308 2119-2145 

Nachod     618 

Polarized   Track,   Boston  Elevated 700 

Railroad    Supply    3072-3074,  3078 

Symbols   for    139-  167 

Union    Switch    &    Signal,    p.    429 

3044-3046,    3053-3060,    3077,    3087-3091 

United   Electric   Apparatus 3063,    3070,    3071,   3092,3096 

United  States  Electric  Signal  System 619,    622 

Relay  Box  658    3104,   3107.  3109,   3152.   3154-3155,   3159- 

' 3172,    3174-3184,    3188-3190.    3197-3223 

Relay    Box   Symbol 77,    82,    83,     90-     92 

Resistance: 

Adjustable  for   Storage  Batteries   on  Track   Cir- 
cuit      2248-2249 

Symbols    for    195-  196 

Resistance    Grids     678-  679 

Resistance   Units,    p.    434 2987,    2988,    2990-2993 

Resistance   Testing  Box 3554 

Rheostat,     p.     488 3545 

Rheostat    Symbol     190 

Rocker     Shaft     Bearings 1282-1289 

Rocker  Shaft  Leadout,  p.   157 1010-1015 

Rock     Island     Lines,     Normal     Clear    Three-Position 

Circuit    501 

Route    Locking 2071-2077,    2084,    2085.2086 


San    Francisco,    Oakland    &    San    Jose.    Alternating 

Current   Signal   Installation,   pp.    113-114 672-  674 

Saxby  &  Farmer  Interlocking  Machines,  pp.  143-149.   790-  850 


haxby  &  Farmer  Interlocking  Machine  Applications- 

Electric  Lock 2790,  2792,  2794,   2795    2801,  2803. 

Hand    Screw    Release 2839     2853 

Time  Lock    ' 

Screw   Driver ' 

Screw    Jaw 

Selective  Signaling: 

Blake   System,   pp.    130-131 729 

G.  R.  S.  Selective  System,  pp.  128-130 721 

Stromberg-Carlson  System,  pp.    131-132...  ,.   734 

United  States  Electric,  pp.  126-128 714 

Western  Electric  System,  p.  131 731 

Selector: 

General  Railway  Signal  Co 

Signal,    p.    160 1Q21 

Stromberg-Carlson    '.'..'.'.'.'.'.'.  734 

Western  Electric .....'. 

Semaphore  Bearings 3352-3356,  3378-3395/3465 

Semaphore  Castings 

3312-3313,  3329-3330,  3370-3377,  3397-3400,  3403-3415/3423 

Semaphore   Indicators 

2550,  2572,  2574-2580,  2583,  2585-2594,  2597-2598,  2600, 

Semaphore  Standard  Indications: 

Block  Signals 225 

Interlocking  Signals 250 

Separators  for  Storage  Battery 3564 

Series  Fouling  Circuit,  Switch  Protection 447 

Set,    Channel    Pin 3603, 

Shackles  for  Wire  Connectors 1293 

Shunt  Fouling  Circuit,  Switch  Protection 

Shunts,  Portable  Alloy 

Sign,  Crossing,  pp.  310,  312 

2146,   2153,   2155-2169,   2196,  2216,   2225,   2230, 

Signals: 

Location  with  Reference  to  Track  Governed 277 

Mechanical,  Pipe  and  Wire  Connected 1639' 

Standard  Symbols 1 

Train    Order 3319 

Typical    Arrangement 3224 

Signal  Bridges,  Symbol  for 

Signal  Circuit  Controllers: 

General  Railway  Signal  Co 2479 

Hall   Style   "E"   Commutator 2476 

Motion  Plate  Pole  Changer 2464. 

Railroad   Supply   Co 2484- 

U.  S.  &  S.  Duplex  Rotary,  p.  354 

Signal  Indications,   pp.   14-20 225- 

Signal  Lamps,  pp.  384-389 2675- 

Signal  Mechanisms,  Automatic  Blocks,  pp.   64-90 512 

Signal  Mechanism  Case: 

Hall  Signal  Co 3421 

Union  Switch  &  Signal  Co 

Signal    Post   Iron   Pipe 3436, 

Signal  Repeater,  p.  371 

Single  Track  Crossing  Bel!   Layout 

2090,    2091,    2093.    2095-2097,2099, 

2100-2102,    2104,    2105,    2107,    2110,    2112,    2114,    2117,    2118, 

Slide   Signal,    Electro-Pneumatic 

Slot  Arm,  Union  Style  "B"  Signal  Mechanism 540- 

Slots,  pp.  205-206,  478-480 1732-1735,  3479- 

Soldering  Torch   

Solenoid  Dwarf   Signal „ 

1773,   1830-1833,   1836-1840,  1910-1911, 

Solenoid   Signal  Mechanism 710 

Southern  Pacific: 

Bootleg    and    Trunking    Run 3851,    3880 

Normal   Clear   Control    Circuit 489,  490,     493 

Number  Plate  for  Block  Signals 3458 

Numbering  Block  Signals 3454 

Pole  Line  Construction 3008-3014,  3016 

Power   Room  Equipment 

Protective  Wiring   

Switch  Adjustment 

Switch  Rod  Insulation 

Switch  Wiring  and  Fouling  Protection 

Southern  Railway,  Trunking  Connections.  .3797-5807,  3810 
Specific    Gravity   of   Storage   Battery   Electrolyte,    p. 
329. 

Spectacle  Clearance,  R.  S.  A.  Diagram 3334 

Spectacle  Rings.  R.  S'.  A.   Standard 3402 

Split  Point  Derail  Details,  Atchison,  Topeka  &  Santa 

Fe    - 1619 

Spokane,   Portland   &   Seattle: 

Drawbridge  Interlocking    1820 

Power   Room   Equipment 2894 

Staff  Catcher  and  Pouch 403-  405 

Staff    Lever    Lock ' 396-  399 

Staffs,   Standard,  Pusher  and  Permissive 402 

Staff   System,    pp.    38-45 374-  405 

Staff    Switch    Lock 400-  401 

Stakes,  Wire  Carrier 1334-1337 

Standard  Interlocking  Machines,  pp.   149-152 851-  902 

Standard  Interlocking  Machine,  Applications: 

Electric  Lock 2791.   2793 

Time    Lock 2832-2833 

Standard   Symbols 1-  224 

Stationary  Batteries,  Installation,  p.  326. 

Stevens  Interlocking  Machine,  p.  156 1006 

Storage  Batteries,   Types  of  Cells: 

Edison  Storage  Battery,  p.  334 2283-2296 

Electric  Storage  Battery 2250-2275 

Gould  Storage  Battery 2281  -2282 

Willard    Storage    Batteries 2276-2280 

Straight   Arm   Compensator 1174-1175 

Strap   Keys 2509,  2512-2531,  2533-2536 

Stuffing  Box 1420-1425 

Style  "C"  Interlocking  Machine,  p.  156 1005 

Sub-station,  Symbol  for 46 

Sunset  Lines,  Clearance  for  Signals  Between  Tracks.  3448 

Suspended  Signal: 

Electro-Pneumatic 1995-1996 

G.  R.  S.  Model  2-A 550 

New  York,  New  Haven  &  Hartford 3444-3446 

Switches,    Knife,   Symbols  for 191-  194 

Switch   Adjustments 1513-1521,  152S-1531 


2810 
2857 
2834 
3562 
1033-1034 

730 

728 
739 
720 
733 

725 
1025 
735 
731 
3468 

-3427 
2602 

•  235 

•  276 
3565 

•  449 
3607 
1304 

446 
3532 

2231 

307 
1706 
33 

3327 
3301 
11 

•2481 
2478 
2474 
2485 
2463 
307 
2729 

•  602 

3422 
3437 
3453 

2604 


2238 
2025 
542 
3492 
3573 


-  711 

3881 

495 

3459 

3455 

3020 

2889 

475 

1531 

3683 

475 

3816 


526 


THE  SIGNAL  DICTIONARY. 


Switches  and  Derails,  Interlocked,  Symbols  for 134-  135 

Switch  &  Lock  Movement: 

Electric,    G.    R.    S 1774-1775 

Electric,   U.    S.    &   S 1874-1877,  1904-1906 

Electro-Pneumatic    1998-1999,  2006-2008,  2017-2020 

Low  Pressure  Pneumatic 2030 

Mechanical  1445-1450,  1457-145S 

Switchboards,  pp.  417-420 1768,  2890-2899 

Switch  Boxes: 

American   2447-2453 

G.  R.  S.  Model  5 1810-1811 

G.  R.  S.  Universal,  p.  350 2438-2444 

Hall  Style  "C" 2427-2428 

Hall    Style    "E" 2425-2426 

Hall  Style   "G,"   pp.  34C-347 2416-2424 

Railroad   Supply 2454-2458 

S*ykes  Point  Detector 2462 

Union  Electric  Selector,  p.  348 2429-2430 

Universal  Switch  Circuit  Controller,  p.   348 2431-2432 

Vertical  Rotary  Switch  Box,  p.  349 • 2433-2437 

Switch  Box  Location,  Symbol  for 84 

Switch  Guard,  p.  193 1604-1610 

Switch   Indicators: 

American  Railway  Signal  Co.,  p.   377 2643-2644 

General  Railway  Signal  Co.,  p.  377 

2636,   2646-2647,   2658-2659 

Hall   Signal   Co.,   pp.    380-381 2630-2632,2645 

Northern  Pacific 3108 

Railroad   Supply   Co 2633-2635,   2654-2655,2657 

Symbol  for 85,   86.   88.   89,  91,  92 

Union  Switch  &  Signal  Co..  p.   381 2637-2642,  2663-2674 

Use  in  Normal  Danger  Control  Circuit 508-  510 

Switch  Insulation   431-467,   472-475,  479-483 

Switch   Lamps 2683-2685 

Switch  Light  Stand 1682-1683 

Switch  Lock: 

American    2820-2822,  2827 

G.  R.    S.,  p.  402 2813-2817,   2823-2824 

Hall    2829,  2830 

Nickerson 1620 

Railroad    Supply    2825,  2826,  2828 

Symbol  for '. 76 

Switch  Machine: 

American    1930,    1933-1940,  1945 

G.    R.    S1 1771,  1797-1802 

Power,   Symbol  for 73 

Triplelock,    p.    481 3493-3494 

Switch  Movement: 

Electro-Pneumatic    1989-1990 

Low  Pressure  Pneumatic 2029 

Switch  Point  Lugs 1486-1512 

Switch  Protection  in  Track  Circuits 432-  464 

Switch  Rod,  Insulated,  Symbol  for 74 

Switch  Rod  Insulation 3659-3660,  3675-3677,  3680-3688 

Switch    Stand: 

Interlocking   Ground    Lever 3495-3510 

Symbol   for   75 

Switch  Valve,  Electro-Pneumatic 2021-2022 

Switch  Wedge  for  Track  Circuit  Insulation 3645-3652 

Sykes  Electric  Tunnel  Signal,  p.  125 713 


T 


Table    Circuit   Controller 2490-2491, 

Tags,     Wire 2388- 

Telegraph     Instruments 3546- 

Telephone: 

Communicating  Circuits.   Manual  Block  Signals.. 

Ringing    Key,   Manual    Signals 339- 

Set    

Symbol     for 

Temperature  Changes,  Effect  on  Compensation 1163- 

Terminal  Block,  R.  S.  A.  Standard 

Terminal  Board,  G.  R.  S.  Interlocking  Machine 

Terminal  Box,  Symbol  for 

Testing   Instruments,    pp.    484-489 3515- 

Three-Position  Signaling,   Standard  Indications 

236-241,        265- 

Throw     Rods 1513-1521, 

Time    Circuit    Breaker 2849-2852, 

Time  Locks,  pp.  405-406 2831-2834,  2840, 

Time  Release: 

G.   R.   S.   Hand  Screw  Release,  pp.    406-407 :. 

2835-2839,     2843- 

Symbols    for 132- 

Time    Circuit    Breaker 2849,    2852, 

U.    S.    &   S.    Clock  Work   Release,   p.    410 2858- 

U.   S.  &  S.   Hand  Release 2853- 

U.   S'.  &  S.  Wall  Type  Hand  Screw  Release 

Tommy    Bar 

Torpedo    3511- 

Torpedo  Machine,  Symbol  for 

Torpedo    Placer    3513- 

Tower: 

Concrete   Block 

Symbols     for 132- 

Tower  Indicators: 

Bryant    Zinc    2570-2571, 

Circuits     2556- 

Federal     

G.    R.    S 2597- 

Railroad   Supply 2551,   2564-2569,   2587-2589,  2593- 

TT.   S'.   &  S 2550,  2562-2563,   2577- 

United    Electric    Apparatus 2552-2555,  2583- 


2505 
2392 
3548 

342 

340 
3551 

215 
1164 
3026 
1764 
79 
3558 

276 

1778 
2855 
2842 


2848 
133 
2855 
2850 
2857 
2856 
3559 
3512 
56 
3514 


1929 
133 

2590 
2561 

2604 
2603 
2593 
25-78 
2586 


Tower    Lamp 2732-2733 

Track    Battery,    Symbol    for 98-  100 

Track  Circuit: 

Alternating   Current 603-  605 

Connections,  East  Boston  Tunnel 707 

Connections,  West  Jersey  &  Seashore 697 

Direct  Current,  pp.  46-55 406-  483 

Tester    3553,   3555,  3576 

Transposition    at    Crossings 468-471 

Track  Indicator,    Illuminated 2615,    2623-2629 

Track    Instruments,    pp.    356-357 2486-2488,    2532 

Track    Instrument    Crossing    Signal,    pp.    320-324 2232-2242 

Track  Instrument  Symbol 55 

Track    Pan,    Symbol    for 42 

Track     Transformer 676 

Train   Describer,    p.    371 2605-2606 

Train    Director's    Board 2617-2619 

Train    Order    Lanterns 2675,  2727 

Train     Order     Signals 3319-3327 

Train    Stops 3691-3700 

Train    Stop    Symbol. 63-    72 

Transformer: 

Indication,   U.    S.   &   S.  Interlocking  Machine 1843-1844 

Power,    p.    432 609,    2970-2977 

Symbols    for 204-  205 

Transposition    of    Track    Circuit    at    Crossings 468-471 

Triple   Lock   Switch   Machines,    p.    481 3493-3494 

Trolley  Contact: 

Eureka   Signal    System 632 

Nachod    Signal    System 616 

Trunking: 

Connections     3732-3816 

Location  at  Siding  and  Crossovers,  A.  T.  &  S.  F.  479-  483 
R.   S.  A.   Specifications,  pp.   517-518. 

Standard    Types 3701-3721 

Trunking   Stake,   C.,   M.    &    St.    P 3876-3879 

Tubes,    Mercury   Arc    Rectifier 2909 

Tudor    Accumulator 2263-2264 

Tunnel     Protection 507,  2083 

Turbo-Generator    Sets 2883-2886 

Two-Position  Signals,  Standard  Indications.  .229-235,    250-  264 


U 

U-Bolt  for  Semaphore  Bearings,  R.  S.  A.   Standard..  3328 

Union  Pacific: 

Automatic  Block  Signal  Location  Plan 3401 

Bootleg     3853-3854 

United  States  Electric  Signal  System,  pp.  96-99 610-  626 


V 

Velocipede    Car    Equipped    with   Gasoline   Engine..,  3587 

Voltmeters     

..3516-3518,    3526-3528,    3530,    3531,    3533,    3535-3537,3536,2558 
Voltmeter    Symbol 213 


w 


Washington  Water  Power,  Alternating  Current  Sig- 
naling,   pp.    111-112 666 

Water    Column,    Symbol    for 

Water  Tank,   Symbol  for 

Wattmeter,  Symbol  for 

Wedged    Switch , 

West  Jersey  &  Seashore,  Alternating  Current  Signal 

Insulation,   pp.   119-120 * 696 

Wire: 

Insulated    3SS4 

Resistance,   p.  511. 

R.   S.  A.  Specifications,  pp.  511-517. 

Symbols    for 219 

Tables  of  Weights,  p.   518 

Wire    Adjusting    Screw 1035,    1307 

Wire  and  Pipe  Connections,  pp.  175-179. ..  .1293-1306,  1413 

Wire    Carriers    1309 

Wire    Compensators 1409 

Wire    Connectors 2352 

AVire    Insulation     3864 

Wire    Sleeves 3028 

Wire    Splice    1305-1306, 

Wire    Tags    2388 

Wire    Terminals    3031 

Wiring    Details     3002 

Wiring   in    Relay    Cases 3216 

Wrought  Iron  Bars,  R.    S.  A.  Specifications,  p.   165.. 


671 
54 
53 
214 
431 

-  697 
-3899 


-  224 

130S 
1419 
1337 
•1412 
2363 
3865 
3030 
3726 
2392 
3034 
3034 
3223 


Zinc    Terminals,   Gravity   Battery,    p.    336 

2300,    2312-231::.    2::i!i-L'::i 


V 


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DUE    AS   STAMPED   BELOW 

fi£C.  C1-,    JUL  2  6   J9 

! 

APR     7  1980 

REG.  cm.     APR  2  4  1990 

JUL     9  1980 

ttc.ca.jwi  2  90 

AUG  201982    . 

~~T 

flETD     JUL  2  2  882 

WOV-  71983 

DTP   PRt    uru      Q  >AS 

KcU  viiC  nu*     T  93 

FORM  NO.  DD  6, 


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